O level Agriculture Notes 2020 teachers copy (1)

O LEVEL AGRICULTURE GUIDE- 2020 GWANZURA .R. 0773266377/ 0714404707 HOLY CROSS HIGH SCHOOL P.BAG 200 MVUMA Table of Contents TOPIC 1: GENERAL AGRICULTURE .......................................................................................... 1 SUB TOPIC: LAND USE ....................................................................................................................... 1 Physical farm planning .................................................................................................................. 1 Crop rotation ................................................................................................................................ 2 SUB TOPIC: ENVIRONMENTAL FACTORS ........................................................................................... 3 Rainfall .......................................................................................................................................... 3 Natural disasters ........................................................................................................................... 4 Disaster risk management strategies ............................................................................................ 6 SUB TOPIC: FORESTRY ....................................................................................................................... 7 Timber harvesting and marketing ................................................................................................. 7 Deforestation .................................................................................................................................... 8 Agro-forestry................................................................................................................................. 9 SUB TOPIC: WILDLIFE ...................................................................................................................... 10 Indigenous knowledge systems in management of natural resources ....................................... 10 Human and wildlife conflicts ....................................................................................................... 13 TOPIC 2: SOIL AND WATER ............................................................................................................ 14 SUB TOPIC: SOIL FORMATION ......................................................................................................... 14 Weathering ................................................................................................................................. 14 physical weathering .................................................................................................................... 14 chemical weathering ................................................................................................................... 14 biological weathering .................................................................................................................. 15 SUB TOPIC: SOIL TEXTURE, STRUCTURE AND PROFILE .................................................................... 15 Soil textural classes ......................................................................................................................... 15 Soil textural classes ..................................................................................................................... 15 Soil structure ................................................................................................................................... 17 Soil structure ............................................................................................................................... 17 SUB TOPIC: SOIL TYPES ................................................................................................................... 18 Improvement of physical characteristics of soils ........................................................................ 18 SUB TOPIC: SOIL CONSTITUENTS .................................................................................................... 19 Importance of soil components .................................................................................................. 19 Types of soil water ...................................................................................................................... 20 SUB TOPIC: SOIL TEMPERATURE ..................................................................................................... 21 Influence of soil temperature on plant growth and soil organisms ............................................ 21 i GWANZURA.R. guide 2020-0773266377 / 0717 558 917 SUB TOPIC: SOIL FERTILITY .............................................................................................................. 23 Fertiliser application ................................................................................................................... 23 Timing of fertilizer application .................................................................................................... 24 Soil sampling ............................................................................................................................... 25 Soil pH and liming ........................................................................................................................... 29 Nitrogen cycle ............................................................................................................................. 30 SUB TOPIC: SOIL EROSION AND CONSERVATION ............................................................................ 32 Conservation methods and structures ........................................................................................ 32 Advantages of cultural methods of soil conservation ................................................................. 34 Disadvantages of cultural methods of conservation ................................................................... 34 Mechanical soil conservation methods ....................................................................................... 34 SUB TOPIC: WATER LOSS AND SOIL DRAINAGE............................................................................... 35 Drainage and water logging ........................................................................................................ 35 Leaching ...................................................................................................................................... 36 SUB TOPIC: WATER CONSERVATION ............................................................................................... 37 Rain water harvesting and storage ............................................................................................. 37 Water pollution ........................................................................................................................... 38 Water legislation ......................................................................................................................... 39 SUB TOPIC: IRRIGATION .................................................................................................................. 39 Methods and types of irrigation ................................................................................................. 39 Choice of an irrigation system ........................................................................................................ 41 Irrigation equipment ................................................................................................................... 42 TOPIC 3: CROP HUSBANDRY ......................................................................................................... 42 SUB TOPIC: STRUCTURE OF FLOWERING PLANTS ........................................................................... 42 Plant anatomy and physiology .................................................................................................... 42 Structure of the stem .................................................................................................................. 43 Structure of the lef ...................................................................................................................... 44 THE CROSS-SECTIONAL STRUCTURE OF A LEAF ........................................................... 45 Adaptations of the Leaf for Photosynthesis ................................................................................ 45 SUB TOPIC: PLANT PROCESSES........................................................................................................ 46 Water and nutrient uptake ......................................................................................................... 46 Transpiration............................................................................................................................... 47 Wilting in plants .......................................................................................................................... 48 Factors affecting transpiration .................................................................................................... 48 Photosynthesis ............................................................................................................................ 49 Translocation and food storage .................................................................................................. 51 ii GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Respiration .................................................................................................................................. 51 Plant tropisms ............................................................................................................................. 52 SUB TOPIC: CROP IMPROVEMENT .................................................................................................. 54 Crop breeding (Maize) ................................................................................................................ 54 SUB TOPIC: CROP PRODUCTION ..................................................................................................... 56 Land preparation ........................................................................................................................ 56 Primary tillage ............................................................................................................................. 57 Secondary tillage ......................................................................................................................... 58 Legume and cereal production ....................................................................................................... 59 Cereal crop production (Maize production) ................................................................................ 59 Maize storage ............................................................................................................................. 64 legume crop-groundnuts ................................................................................................................ 67 SUB TOPIC: CROP PROTECTION ...................................................................................................... 71 Pests ............................................................................................................................................ 71 Diseases ...................................................................................................................................... 73 Weeds ......................................................................................................................................... 74 Agrochemicals ............................................................................................................................. 77 TOPIC 4: ANIMAL HUSBANDRY ..................................................................................................... 78 SUB TOPIC: ANATOMY AND PHYSIOLOGY ....................................................................................... 78 Digestive system of a ruminant and non-ruminant ..................................................................... 78 Digestive system of hen .............................................................................................................. 80 Reproductive system of a ruminant ............................................................................................ 83 Reproductive system of a cock ................................................................................................... 84 The female ruminant reproductive system (cow) ....................................................................... 85 The reproductive part of a hen ................................................................................................... 86 SUB TOPIC: ANIMAL NUTRITION ..................................................................................................... 87 Types of feeds ............................................................................................................................. 87 Maintenance and production rations ......................................................................................... 88 SUB TOPIC: SMALL LIVESTOCK PRODUCTION ................................................................................. 90 Rearing of either rabbits or layers or indigenous chickens ......................................................... 90 Slaughtering, processing and marketing ..................................................................................... 92 SUB TOPIC: NON-RUMINANTS ........................................................................................................ 93 Rearing of Non-ruminants: Pigs or donkeys ................................................................................ 93 Management of cattle or sheep or goats .................................................................................... 94 SUB TOPIC: ANIMAL HEALTH .......................................................................................................... 96 Notifiable livestock diseases ....................................................................................................... 96 iii GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Animal parasites and immunisation .......................................................................................... 100 One host tick ............................................................................................................................. 100 Two- host tick............................................................................................................................ 100 Internal parasites (endo-parasites) ........................................................................................... 101 SUB TOPIC: ANIMAL IMPROVEMENT ............................................................................................ 103 Genetics .................................................................................................................................... 103 SUB TOPIC: ANIMAL IMPROVEMENT ............................................................................................ 107 Breeding .................................................................................................................................... 107 TOPIC 5: FARM STRUCTURES AND MACHINERY ......................................................................... 108 SUB TOPIC: FARM IMPLEMENTS ................................................................................................... 108 Maintenance ............................................................................................................................. 108 SUB TOPIC: FENCING ..................................................................................................................... 113 Treatment of fencing materials................................................................................................. 113 FENCING.................................................................................................................................... 114 Fencing specifications ............................................................................................................... 114 Anchors and fencing calculations .............................................................................................. 115 SUB TOPIC: FARM BUILDINGS ....................................................................................................... 116 Farm buildings........................................................................................................................... 116 Designing livestock buildings .................................................................................................... 120 SUB TOPIC: FARM ROADS ............................................................................................................. 123 Features of farm roads .............................................................................................................. 123 FARM ROADS ............................................................................................................................ 123 Road construction and maintenance ........................................................................................ 125 SUB TOPIC: APPROPRIATE TECHNOLOGY ...................................................................................... 129 Irrigation pumps ....................................................................................................................... 129 Shellers ..................................................................................................................................... 129 TOPIC 6: AGRI-BUSINESS ............................................................................................................. 132 SUB TOPIC: PRINCIPLES OF ECONOMICS ....................................................................................... 132 Opportunity cost and choices ................................................................................................... 132 Opportunity cost ....................................................................................................................... 133 Demand, supply and price ........................................................................................................ 134 Diminishing returns ................................................................................................................... 137 Risk and uncertainty ................................................................................................................. 138 Decision making ........................................................................................................................ 139 SUB TOPIC: FARM BUDGETING ..................................................................................................... 140 Budgets ..................................................................................................................................... 140 iv GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Farm records and accounts. ...................................................................................................... 141 Farming costs . .......................................................................................................................... 142 SUB TOPIC: AGRICULTURAL MARKETING ...................................................................................... 144 Functions and factors of marketing .......................................................................................... 144 Marketing legislation ................................................................................................................ 145 CONTINUOUS ASSESSMENT ............................................................................................................. 149 PROJECT ........................................................................................................................................ 149 MARKING CRITERIA ................................................................................................................. 152 v GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ******************************************** FORM 3 TOPIC 1: - FORM 4 GENERAL AGRICULTURE ********************************************* SUB TOPIC: LAND USE ********************************************* Physical farm planning  discuss the importance of physical farm planning Importance of physical farm planning  it helps in: - establishing a clear direction for management and employees to follow. - Defining measurable terms of what is most important for the farm. - Allocating resources (labour, machinery, equipment, building and capital) more efficiently. - Establishing a basis for evaluation of management decisions and key employees - Providing a management framework that allows quick responses to changing conditions - Highlighting water and access routes such as roads - Assessing the feasibility of planning to increase the cropping and livestock rates - Assessing the site in terms of present and future potential use. - Planning sites where to build shelters. Factors to consider when planning - Land – the availability of land and how much of it is arable. Labour- the availability of labour and the type of labour required for different agricultural activities. Capital – the amount of capital needed to start agricultural activities. Water resources- The availability of a water source and how reliable it is. Farm supplies – the location of areas to acquire farm supplies and the distance to the location. Markets- the location and availability of market for the produce is also important. Budgeting- the budget is important to determine the viability of the project. 1 ********************************************* Crop rotation    outline principles of crop rotation design a four crop rotation cycle discuss the advantages of crop rotation crop rotation - is the practise of growing a series of different types of crops in the same area in sequential seasons. Designing a four crop rotation cycle. Types of rotations. Grass ley rotation: Is a rotation which includes a period in grass which is used for grazing and conservation. Continuous cereal and break crops. For example; maize- soya bean – maize, cotton – maize- cotton, tobacco – maize- maize, maize- wheat- soya bean maize, tobacco- grass- grass- grass- tobacco. year 1 year 2 year 3 year 4 carrots(root crop) beans(legume) rape(brassica) maize(cereal) Principles of crop rotation - shallow rooted crops should be followed by deep rooted crops - crops of the same family should not follow each other. - Always include a legume - Add manure or organic matter regularly - Grow crops suited to the climatic conditions of the area - Soil type should be correct for the crops selected Advantages of crop rotation - Improves the soil structure. - Reduces build-up of pests and diseases - Helps improves soil fertility by including a legume - Helps manage soil pH - Soil erosion is minimised - Some of the weeds are effectively eradicated 2 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* SUB TOPIC: ENVIRONMENTAL FACTORS ********************************************* Rainfall   describe distribution, effectiveness, reliability and intensity of rainfall in Zimbabwe explain the effects of distribution and intensity of rainfall on agricultural activities Rainfall - is precipitation in the form of water droplets released by clouds. Effective rainfall - it is the rainfall which supplies adequate soil moisture for plant growth. Season length - Refers to the duration of effective rains in a particular region. Rainfall distribution - Refers to how the effective rainfall is shared or spread throughout the season - It determines season quality - Rainfall must be distributed in such a way that it is available during critical growth stages like germination, flowering and grain filling. - These plant growth stages are sensitive to moisture stress and inadequate soil moisture during these stages severely decrease final yield. - The distribution of rainfall is quantified in terms of rainy pentads in a given region. - A rainy pentad is defined as the second one of three five – day periods (pentally) which together receives more than 40 mm and any two of which receives at least 8 mm of rainfall. - A large number of rainy pentads show that there is good distribution of rainfall in the season. - Natural region 1 and 2 tend to have more rainy pentads and consequently higher crop yields than region 3,4 and 5. Rainfall reliability - This means that rainfall is received regularly within a season and from season to season in amounts which are normal for that region. - Cropping programmes where rainfall is reliable can be planned to make full use of the rain. Cropping twice in the same season may also be done. - Unreliable rainfall/ mid-season droughts/ dry spells are experienced in natural region 3.4, and 5. Rainfall intensity - This is the amount of rainfall received in an area per given time period. - High intensity means a large amount of rainfall has been received in a short time. 3 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Rainfall which has high intensity is not very effective because it is quickly lost as runoff from the field before it percolates into the soil. Rainfall of low intensity falling over a long period has a better infiltration rate and is highly effective. Effects of rainfall on agricultural activities  Low rainfall causes animals to become weak and thin due to inadequate pastures  Severe case of drought lead to deaths as there will be no pastures or water to drink.  Animals lose body condition due to infection by internal parasites such as liver fluke and tape worm which breed in damp and swampy areas if there is too much rainfall.  The disease root rot may develop under conditions of excess rainfall  Drought causes wilting and drying up of crops.  Drought also results in low crop yields of low quality.  Excessive rainfall causes lodging of plants; dropping of flowers, leaves and fruits  Stunted growth and yellowing of plants take place due to nitrogen deficiency caused by excessive rainfall  Some plants, particularly in clay soil will develop root rot disease under very wet conditions. ********************************************* Natural disasters  explain the effects of natural disasters on agriculture  Hailstorm  Floods  Cyclones  Whirl wind  Veld fire  Drought  Heat wave November 1997 b). Explain how each of the following will reduce crop production. i). Strong winds - break branches - shed flowers, pollen, fruit leaves - affects photosynthesis - reduces yield and quality ii). Low rainfall - causes drying, moisture stress - plant food manufacture is reduced - poor germination - poor yield - quality of produce is affected iii). High temperatures 4 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - transpiration rate is increased rate of evaporation rises plants wilt and die poor quality of produce and low yields November 1996 1a). Explain the effects of drought, wind and hail on crops. (5) b). Describes the measures the farmer can take to minimize the effects of the crop hazards mentioned in 11(a) above. (5) Possible Answers a). Explain the effects of drought, wind and hail on crops Drought - reduced growth of crops - Crops dry - Poor yields - Quality of crops is reduced Wind - necessary for pollination in some plants An agent for dispersal of seed Can have a cooling effect - increasing rate of evaporation Strong winds cause crops to dry up Can break branches, stems and fruits dropping Spread pests and diseases fast Hail - shred leaves, flowers and crop stems - Cause branches, stems and fruits to break November 1998 12a). List five causes of crop damage other than pests and diseases. (5) b). Explain how each one cause damage to crops. (5) Possible Answers a). List five causes of crop damage other than pests and diseases - drought hail extreme temperatures water logging capping / crusting excessive use of fertilizers fire weeds frost flooding wind nutritional deficiency b). Explain how each one causes damage to crops 5 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 drought - plants wilt/ dry hail - tear / breaks/ crops water logging - suffocation of plants / stunted growth affect microbial activity capping affects infiltration of water affects germination affects aeration fire destroys crops wind - encourages evaporation/ transpiration - breaks plants/ crops / lodging of crops Nutritional deficiency – retards growth of plants ********************************************* Disaster risk management strategies  outline precautionary measures to guard against natural disasters  Weather forecast  Disaster preparedness  Conservation structures 6 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* SUB TOPIC: FORESTRY ********************************************* Timber harvesting and marketing    describe methods of harvesting trees discuss methods of treating timber identify possible markets HARVESTING - Trees are mature for harvesting at six to eight years of age depending on the species and rainfall. - At maturity the trees are 8-13cm in diameter. cutting is best done in early spring (late October-November) because: - It is easier to strip the bark off poles at this time. - New shoots grow out more readily if cut at this time. - N.B. Cutting is down using axes or bow-saws, with each tree being cut just above the ground 10cm or less. This is because; - Regrowth is better if cut low - The shoots are more stable if coming from near ground. - The trees should be cut at an angle to have a sloping surface to ensure that water runs off stool thus preventing rotting, leading to death of the stool. Methods of harvesting trees - Hand felling- trees should be cut 10 cm above ground using a hand axe or machine operated saws. Machine felling-this is done using motorised chain saws. Trees should be cut at an angle to avoid water accumulating on the stump which may cause rotting. After felling trees the regrowth on stumps are called coppices Clear cut – this is the removal of all trees in the area, no tree will be left standing Shelter wood cut- mature trees are removed in 2-3 harvests over a period of 1015 years. This method allows regeneration of medium to low shade towering species. METHODS OF TREATNG TIMBER - Using creosote, tar oil or grease: poles are immersed in hot creosote, tar oil or grease and heated for an hour and left in the liquid for a further 24hours. - After drying the poles are ready for use and remain protected for a very long time. - For short term protection -used oil ‘may be used to coat the poles and timber. - use of used oil. 7 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Seasoning- this refers to drying of timber through evaporation of excess moisture either by natural (air drying) or artificial (kiln drying) methods Partial drying Possible markets for timber - industry for paper manufacturing - Manufacturing of furniture, - Mining for making pillars - wood for fuel for example households and tobacco curing. - construction eg houses, and fencing ********************************************* Deforestation     describe causes of deforestation explain effects of deforestation suggest possible solutions to deforestation explain importance of afforestation and reforestation Causes of deforestation - clearing land for cultivation. - collection of wood fuel. - Cutting down for construction of houses and roads - Mining, particularly open cast where large tracks of land are cleared - veld fires - Construction of dams - Logging- wood based industries destroy large forests Effects of deforestation - Soil erosion- soils are exposed resulting in washing away of topsoil. - The water cycle is affected as evapotranspiration is reduced. - Loss of biodiversity- there are a number of plant species wiped out and animals that depend on the plant as habitat - Climate change due to accumulation of carbon dioxide in the atmosphere. - land degradation. - Siltation of dams- accumulation of soil in water bodies. Possible solutions of deforestation - Re-afforestation and afforestation programmes to establish exotic and indigenous woodlots. - Develop alternative energy sources rather than depend on wood, alternative sources may include liquid petroleum (gas) or electricity or solar power. - government to pass and enforce laws to preserve existing forest resources. - Improved farming methods- this will prevent the indiscriminate cutting down of trees. 8 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - encourage farmers to plant trees for poles and curing tobacco, instead of using wood as fuel they can use coal instead. Importance of afforestation and reforestation - Trees can control runoff and soil erosion thereby reducing siltation and water loss - Trees maintain soil organic matter - Trees reduce soil toxicities (acidification and salinization) - Forests utilise solar energy efficiently. - Trees help to reclaim eroded land. - forests play an environmental and ecological role. trees moderate microclimate in residential areas. leguminous trees fix atmospheric nitrogen Helps in apiculture (bee keeping). income for famers. - ********************************************* Agro-forestry    identify agro-forestry components discuss the importance of agro-forestry practices establish agro-forestry plots Agro-forestry - Refers to Land- use systems in which trees or shrubs are grown in association with agricultural crops, pastures, or livestock and in which there are interactions between trees and other components. Advantages - The land is fully utilized. - Labour is always in use all the times. - Livestock gain food from crops and tree leaves. - Crops gain manure from the animals kept. - Prevent erosion as the land has a cover. Disadvantages - Trees harbour pests such as birds and insects harmful to crops. - Presence of trees makes ploughing or cultivation operations difficult. - Technical know-how is required. 9 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* SUB TOPIC: WILDLIFE ********************************************* Indigenous knowledge systems in management of natural resources     explain how cultural values and beliefs affect the management of natural resources explain how principles of conservation and preservation affect wildlife trading describe effects of poaching discuss biodiversity in relation to genetics, species and ecosystem diversity describe habitats of wild animals Indigenous knowledge systems in wildlife conservation and preservation - indigenous knowledge systems (IKS) are a body of knowledge, or bodies of knowledge of the indigenous people of particular geographical areas that they have survived on for a very long time. - IKS is local knowledge that is unique to a given culture or society. - IKS is built by societies through generations of living in close contact with nature. It includes norms, taboos, a system of classification of natural resources, a set of empirical observations about the local environment and a system of selfmanagement that governs resource use. Use of Totems - Amongst traditional communities such as the Ndebele and Shona where totemic is practiced, it is taboo for clan members to kill animals which serve as the revered symbol of their families. - the family members whose totem is symbolised by a certain animal become custodians of that particular animal. Taboos and rules - Protection of wildlife through taboos and cultural laws was very common in the Zimbabwean culture as well as other African societies. - sacred animal species being for example owls, snakes, pangolins, tortoises and porcupines - It has been studied that in some Zimbabwean cultures, snakes symbolised the ancestral beings. Consequently, it was taboo for the local people to kill them. The belief in these symbolic snakes was a favourable factor which necessitated their annual increase in numbers. - Although, it has been reported that taboo species may still suffer from human impact, as they are not necessarily free from being poached by other people who doesn't value them also as taboo species. 10 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - Thus it has been shown that formal rules and informal law enforcement regulations are important in influencing the behaviour of people in natural resources conservation. Some plants are taboo to chop down or use as firewood eg umphafa (also known as umlahlabantu) used in burial ceremonies. some animals are also taboo to kill e.g swallows (inkonjane, nyenganyenga) who are believed to signal the coming of rainfall. Sacred areas - The local names of these areas differ between regions (e.g., indawo ezizilayo, masango anoera, nzvimbo dzinoera) and are usually included in areas regarded as sacred sites in revered areas, - local people refrain from cutting down trees, killing animals, harvesting useful plants within such sites, or even entering or passing nearby, believing that the spirits or deities would be offended and bring harm to the persons, families, or even whole villages if the sites are disturbed. - What is generally known, however, is that these areas exist in communal areas all over the country, but are scattered, and in the form of grazing lands, watersheds and even mountains - Matopo Hills are examples of such a place, they are of spiritual significance to the Ndebele and Shona people. Important traditional ceremonies are conducted at shrines in these hills; for example, during severe drought rainmaking ceremonies are often performed at the Njelele shrine. - It is believed that the ancestral spirits of the people live among the hills. - In most African communities, the ancestral spirits are believed to be living in the forests and special trees, caves and ruined homes and water bodies. - There are studies that have been carried out that claim that certain sacred hills were places of abode for ancestral spirits. Also, echoes of music and dance used to be heard on the following day after Mukwerera rainmaking performances. - The Amarula and Muhachi trees are of special mention in Matobo. - It is equally taboo to hunt or poach animals within or running into a sacred forest because they belong to Mwari and the ancestral spirits. - Such landscape elements are therefore normally treated with veneration to ensure limited human access into them lest the spirits be offended and driven away „homeless‟. - In this regard, it is taboo to cut down trees found in a sacred place without the sanction of the local chief priest. - Furthermore, it was found out that the community members were culturally not allowed to fell trees from these sanctified hills and they [hills] grew into thick forests. - Thus the indigenous knowledge system was utilised not only to protect wild animals and deforestation; it was a tool that intensively combated soil erosion as well. Special meat for chiefs - Such animals as the pangolin should not be eaten by anyone except the chief, since the chiefs are few the pangolin will be preserved 11 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Principles of conservation and preservation and how they affect wildlife trading - Parks and wildlife act of 123/1991 chapter 20:14 – the act seeks to guarantee that the wildlife heritage of Zimbabwe is protected through sound management and restrictive laws - The restrictive laws include the fact that no persons is allowed to hunt for any wild animal without authorisation from the responsible government department and may not trade in any of the products that are obtained from the wild animals. - the act also provides for the establishment of national parks, botanical gardens, sanctuaries, and safari areas where the wildlife is protected and this also restricts the trade in wildlife. - CAMPFIRE is another programme that helps in restricting the trade in wildlife as it seeks to benefit communities who live with the wildlife. - non-governmental organisations such as World Wide Fund for nature (WWF) who are involved in wildlife conservation. - CITES is an international agreement which forbids commercial trade in endangered species while allowing trade in species that can withstand the pressures of trade. Effects of poaching -Loss of biodiversity. - Extinction. - Imbalance in the ecosystem. - Animals that depend on a particular species is also affected. - Loss of foreign currency. - Loss of income for people who depend on tourism and wildlife. - Biodiversity in relation to species, genetics and ecosystem diversity - Biodiversity- refers to a variety of plants and animals that exist in a particular natural environment. - Species diversity-refers to the number of different species in an area - Ecosystem diversity –refers to the number of different ecosystems in an area - Genetic diversity-the sum total of genetic information contained in genes of organisms Habitats of wild animals - Habitats of wild animals include, water, soil, trees, rivers, dams, caves and sea. - causes of differences in wildlife habitats include:  Genetic makeup.  climatic factors.  soil factors (physical).  competition between species.  diets and feeding patterns. 12 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* Human and wildlife conflicts     discuss possible conflicts between humans and wildlife explain the existing legislation in managing wildlife resources in Zimbabwe discuss the role of Government and voluntary organisations in wildlife management discuss the role of international conventions in wildlife management Conflicts between humans and wildlife.  Competition for water and food.  Animals (e.g elephants) destroy man’s crops.  Man hunts down animals.  Leopards, Lions etc attack humans. Roles of National Parks - They are responsible for research e.g. investigation and monitoring animals. - They protect animals from attack by man (poaching). NGOs (Non- Government Organizations) They help the government by funding research, protection and development of game parks. CITES - Affects the marketing of Wildlife products. - Caters for species treated with extinction e.g. black Rhinos. CAMPFIRE Functions of CAMPFIRE - Protects trees and wild animals against poaching - Used to improve infrastructure e.g. roads - Generate funds which are used to build schools, clinics etc for rural communities. - Community gets forex through tourism in game parks etc. 13 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* TOPIC 2: SOIL AND WATER ********************************************* SUB TOPIC: SOIL FORMATION ********************************************* Weathering  discuss various forms of weathering physical weathering - Results in the rock crumbling or breaking into smaller particles without any chemical changes. It increases the surface area available for chemical weathering. Physical is accomplished by the following factors: Changes in temperature - When the sun heats the rock during daytime, the outer layer warms up faster than the inside, resulting in different rates of expansion of the outer and inner layers. At night, the outer layers cool more rapidly than the inner ones resulting in differential contraction of the rock. A repetition of this sequence of expansion during the day and contraction by night results in cracking and finally peeling off of the outer layer. This is known as exfoliation or onion weathering. freezing water - Water collects in a crack and when it freezes it expands and breaks up the rock. Abrasion - Wearing away of rock due to bouncing together of rocks. - Running water can use stones which it carries as abrasive tools which erode the underlying rock material or bedrock. The scratched or abraided rock particles will become raw materials for chemical weathering. Wind - Sand particles carried by strong winds may wear down exposed rocks by friction. chemical weathering - Rock particles or parent material are further broken down through chemical reactions. The minerals within the rock particles are changed chemically resulting in further breakdown of the rocks. Water is essential in chemical weathering. There are a number of chemical weathering reactions involved in chemical weathering and these include hydrolysis, carbonation and solution. Hydrolysis - It is the replacement of cations within the rock by hydrogen ions. - Cations are positively charged particles of elements and replaced cations are sodium,potassium,calcium, and magnesium. - The replaced cations go into soil solutions and are absorbed by plants. - The removal weakens the rock and makes it more susceptible to breakdown. 14 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Carbonation - This is the action of carbonic acid which is produced in the soil. - This sis a weak acid which reacts with bases to form carbonates which are soluble salts. - Since the salts are soluble they drain out the rock leaving a weak structure which easily crumbles. Solution - Compounds or salts simply dissolves into water and are drained out off the parent material leaving a weak structure which crumbles. biological weathering - Breakdown of rocks or change of materials brought about by direct or indirect action of living organisms. These can be plants, animals or microorganisms. Plant roots grow through the smallest cracks in rocks and stones. As roots increase in size the cracks are widened and the rock breaks apart. In addition, plant roots secrete chemicals which breakdown rocks chemically. ********************************************* SUB TOPIC: SOIL TEXTURE, STRUCTURE AND PROFILE ********************************************* Soil textural classes   list the eight textural classes determine textural class of a soil using textural triangle Soil textural classes - soil consists of particles which vary in size namely sand, silt and clay. Each of the se particles can be referred to as a soil fraction and the millimetre (mm) is the unit of measuring their sizes. Classification of soil fractions Name of particle (Fraction) Clay Silt Sand Gravel Diameter of soil particles (mm) Less than 0.002 0.002 - 0.02 0.02 – 2.0 Greater than 2.0 15 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - in practice, soils do not consist of 100% sand, silt or clay but are mixtures of these three components or particles. the percentage composition of sand, silt and clay in a soil is known as soil texture. in Zimbabwe eight (8) textural classes have been identified and these are given in the table below: Textural class Sand Loamy sand Sandy loam Sandy clay loam Clay loam Sandy clay Clay Heavy clay Definition Over 85% sand 75% - 85% sand Less than 20% clay and 50% - 75% sand 20% - 35% clay, 45 – 80% sand 20 – 40% clay and less than 45% sand Greater than 35% clay and 45 – 65% sand Greater than 40% clay and less than 45% sand Greater than 50% clay. These are stiff, sticky clays with shiny surfaces when dry. Explain the importance of the following on plant growth: Soil texture. [4]  a good texture enables a soil to adsorb and return moisture and nutrients; 16 GWANZURA.R. guide 2020-0773266377 / 0717 558 917    have adequate movement of air and water within them; easy to till; the rate and direction of many chemical reactions is influenced by particle size range of the soil. ********************************************* Soil structure    identify methods of improving and maintaining good structure explain factors affecting soil structure explain the importance of soil structure Soil structure - soil structure refers to the arrangement of the soil particles (sand, silt and clay) into clusters called peds or aggregates. soil structure may be changed by the farmer. soil structure may be blocky, platy, prismatic or spheroidal. The spheroidal structure is further subdivided into 2 subclasses: crumb and single grain. the crumb structure is the most ideal for crop production because it has good aeration, good drainage, can be easily worked on, allows good root penetration and has good water and nutrient holding capacity. Methods of improving and maintaining good structure - application of organic manure, composts and green manure. - cultivation of soil when not too wet or too dry - addition of agricultural lime. Lime results in more particles combining together to form crumbs through a process called flocculation - include crops with high leaf litter in a crop rotation programme. The litter will eventually decompose to humus which binds the soil into a good crumb structure. - maintain well drained soils - practising minimum tillage reduces destruction of soil structure by tillage equipment Factors affecting soil structure - excessive tillage breaks down soil structure - use of heavy machinery in the field compacts the soil and breaks down soil structure - working on the soil when it is too wet or too dry breaks soil structure - practising monoculture - waterlogged conditions The importance of soil structure Explain the importance of the following on plant growth: Soil structure. [4] - provides good aeration; allows good root penetration; there is high nutrient retention ability 17 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - there is adequate aeration for root respiration and soil microbes there is high water holding capacity due to the porous crumb structure soil is friable, that is, it can be easily worked on it also increases the resistance of soil to water and wind erosion ********************************************* SUB TOPIC: SOIL TYPES ********************************************* Improvement of physical characteristics of soils  describe methods of improving different soil types - Sand and clay soils  Manuring soils  Adding anthill soil to sand soil  Liming Improvement of physical characteristics of soils - Ways of improving: Sandy soil    addition of manure addition of ant-hill soil addition of suitable clay soil Clay soil   addition of manure addition of lime Loam soil - Loam soil can be maintained through:  liming  addition of organic matter describe any two effects of adding lime to the soil. [2]  improves soil structure;  improves soil pH/ raise pH/ reduce acidity;  improves availability of nutrients/ soil fertility  improves microbial activities;  reduces toxicity of insoluble compounds; what are the advantages of clayey soil over sandy soil? [6]  High water holding capacity;  Soil is compact and cannot be eroded easily;  Has more humus;  Low leaching;  High microbial activity;  High fertility; 18 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* SUB TOPIC: SOIL CONSTITUENTS ********************************************* Importance of soil components       describe the composition of an agriculturally viable soil explain the importance of each soil component describe the types of soil water explain movement of water in the soil explain field capacity explain the role of living organisms in the soil Soil Constituents Soil Composition - the soil is composed of rock particles (mineral matter), organic matter, water, air and living organisms. The percentage composition of the constituents is as shown in the figure below: Soil composition Air 25% Water 25% Mineral matter 45% Organic matter 5% 1. Mineral matter - the weathered rock particles or mineral matter are also called inorganic matter, meaning they are not of plant or animal origin. 19 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - the majority of Zimbabwean soils are known as mineral soils because they have a high percentage of mineral matter. They are derived from the weathering or breakdown of rocks. mineral matter forms a greater part of the soil, making 45% of the soil by volume. - 2. Organic matter - organic matter may be fresh leaves, plant stalks or droppings of animals. - -it may also be decomposed plant and animal matter 3. Soil air - soil air consists of oxygen, carbon dioxide, nitrogen and water vapour. - it is found in the spaces between the soil particles. - the oxygen part is essential for root respiration of soil organisms, germination and many chemical processes occurring within the soil. - soil aeration can be improved by: • • Applying organic matter to the soil, for example, farmyard manure, compost and green manure. These give the soil a crumb structure which provides adequate air space. Improving drainage of waterlogged soils. If a soil is waterlogged it means all the air spaces are filled with water. By draining this excess water air will occupy these spaces. 4. Soil water - soil water is important because it: i. ii. iii. iv. - Aids the germination of seed Aids weathering since weathering occurs in a moist environment Dissolves nutrients which are then absorbed in solution by the plant Keeps plant cells turgid soil water can be classified into three types which vary in their availability to plants. These are: Types of soil water 1. Free or Gravitational or Drainage water - this is excess water which a soil cannot retain and is drained downwards through the soil by the force of gravity. - it is more than the soil can hold and therefore moves down. - this type of water is undesirable because it leaches (washes down) plant nutrients out of the crop’s rooting zone and thus making the unavailable to plants. - it is also undesirable because it reduces soil aeration by filling up the air spaces. 2. Hygroscopic water - this is an extremely thin layer of water around each and every soil particle which is absorbed from atmospheric vapour. - it can only be seen after heating air-dried soil - it has no value to plants because it exists as a very thin film with a very high force or tension. This force is so high that plant roots cannot extract or absorb this water. 20 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 3. Capillary water -this is water which surrounds soil particles in a thin layer outside the hygroscopic layer. -it moves from wet to dry areas or from the water table upwards in all directions -it is held in small pores called capillary pores and also moves through these pores to drier parts of the soil. ********************************************* SUB TOPIC: SOIL TEMPERATURE ********************************************* Influence of soil temperature on plant growth and soil organisms     explain the effects of soil temperature on plant growth and soil organisms outline optimum soil temperature range for growth of most crops explain effects of extreme temperatures on various stages of crop growth outline measures that can be taken to reduce the effects of extreme soil temperatures - temperature is the degree of hotness or coldness of a body, for example atmospheric air and the soil. it is important for a farmer to know both the maximum and minimum temperatures for each day as both extremes can have adverse effects on crop growth. in agriculture we are more interested in soil temperature. Soil temperature is directly related to the amount of heat (warmth) within the soil environment. warmth of the soil is important because: 1. It is necessary for germination 2. The uptake of water and nutrients by crops is higher in warm soils than in cold ones 3. Increased growth rate in (ii) above means crops and fruits open earlier 4. There is increased activity of soil micro-organisms resulting in: - (a)increased breakdown of organic matter with subsequent release of nutrients (b) nitrogen being readily available through nitrification Optimum temperature range for : the maximum temperature for germination is 38oC and the minimum is 5oC. The optimum is 30oC. Effects of excessively high temperatures - very high temperatures usually about 300C damage crops through wilting, scorching and death. Even with moisture available in the soil the plants are unable to cope with the rate of water loss through transpiration which is greater than that of uptake from the soil. - if the soil is exposed to direct sunlight it might be so hot that the roots near the soil surface may die. 21 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - at high temperatures, plants may abort as flowers are forced to drop and no fruit set will take place. some plants may ‘bolt’ when they should be growing vegetatively. seeds may fail to germinate. microbial activity is reduced. Methods of reducing effects of excessively high temperatures 1. Supply of adequate water through irrigation. 2. Mulching – covering the soil surface with a layer of plant material (grass leaf, litter, compost, manure or crop residues). The mulch’s function is to reduce water loss through evaporation, slow down temperature fluctuations and reduce weed growth. 3. Shading of transplanted seedlings – this involves the sticking of leafy twigs around a seedling soon after transplanting to provide some shade. The shade prevents excess heat on the seedling and reduces the amount of evaporation. This improves the survival rate of seedlings. 4. Transplanting under cool (such as late afternoon) or cloudy conditions. Effects of excessively low temperatures - very low temperatures which occur at certain nights and reach or go beyond the freezing point (00C) cause frost. - crops differ in their susceptibility to frost and the following damages can be inflicted on the crop: 1. Tissue necrosis (death) - the leaves and stems of affected plants are killed if temperature goes below freezing point. - the affected plant tissues turn brown. - the most affected plants in Zimbabwe are tomatoes, potatoes, coffee and tobacco seedlings. 2. Injury to flower buds and flowers - in wheat the flowers become sterile and therefore produce no seed if exposed to more than four hours at -2oC . The damage increases with decrease in temperature. 3. Fruit injury - the fruit skin gets discoloured resulting in the lowering of fruit quality. 4. Injury to underground storage organs - potatoes and onions show brown patches if bitten by frost 5. Reduced germination of seeds and reduced plant growth rate. Methods of reducing effects of excessively low temperatures (frost) - Protection measures can be divided into long and short term methods. (a) Long term methods • Avoid areas prone to frost such as valleys and lower slopes. This applies to tea, coffee and tobacco seedlings (sown in winter). 22 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 • Choose planting dates which avoid frost hitting the crop at its susceptible growth stage. In wheat this is done by planting it in early May so that flowering does not coincide with frost. Construct frost barriers – a barrier of thatch grass around a crop will guard against cold air. This is suitable for tomatoes and tobacco seedbed sites. Soil management done by keeping the soil: 1. Compact - excludes too much air (poor heat conductor). This allows more heat to be conducted to the surface. 2. Free of mulch - mulch produces air pockets which result in poor conduction of heat. 3. Moist soil – a better conductor of heat than dry soil. 4. Uncultivated since cultivation creates air pockets. • • - (b) Short term methods These methods can be used when there is a high likelihood of frost occurring on a particular night. • Sprinkling (irrigation) – water is sprinkled continuously once the temperature reaches 1oC until the danger of frost is over. Thus water is warmer than atmospheric air , and therefore the latter is warmed. • Creating fires – this is achieved by burning diesel oil, old worn-out tyres, crop residues or grass. ******************************************** SUB TOPIC: SOIL FERTILITY ********************************************* Fertiliser application    describe different methods of fertiliser application Applying organic and inorganic fertilisers calculate fertiliser application quantities per given area differentiate basal from top dressing Soil fertility -fertilizers Methods of fertiliser application i) Broadcasting - this is done by spreading fertilizer uniformly on the soil surface This method is usually done before planting and the fertilizer is incorporated into soil through discing or ploughing under. Advantages- it can be done by hand or by machine and it has low labour requirements and it is fast. Disadvantages- nutrients cannot be fully utilised by roots as they are not concentrated in the root zone, weed growth is promoted 23 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - ii) Foliar application This refers to spraying of fertilizer solutions on the leaves of growing plants, some nutrients are readily absorbed by the leaves e.g. zinc, boron, iron and manganese which are dissolved in water and absorbed, Advantages- effective as fertilizer is applied directly on to plant, and the fact that it can be applied together with pesticides to reduce costs. Disadvantages- if amounts are not correct i.e. excess amount it may result in scorching of leaves and the method is only limited to micro nutrients iii) Fertigation - This is the application of water soluble fertilizers to crops through irrigation water. The fertilizers are then carried to the soil by water in solution. Advantages- very effective as nutrients in solution are easily absorbed by plants. Disadvantages- high chances of leaching in sandy soils iv) Hill placement - This is when fertilizer is placed on the side of every plant, usually a standard cup is used in such a way that each cup corresponds with a certain mass of fertilizer. - Advantages- minimum contact between the soil and fertilizer, weeds do not use fertilizer as it is localised to the plant, the fertilizer is localised to the plant and nutrients subsequently are close to the root zone and the next crop in the cycle also benefits from the fertilizer. - Disadvantages- requires a lot of labour. v) Banding - A continuous line of fertilizer applied in furrows alongside planted crop rows. the fertilizer is placed deeper than the seed on the side. This method can be done also on growing crops - Advantages-no direct contact between seed and fertilizer. - Disadvantages- it is time consuming and requires machinery vi) Dollop method - This is done by making a small shallow hole where fertilizer is placed and coverd by soil. - Advantages- prevents loss through volatilisation - Disadvantages- labour intensive, and poor nutrient uptake Fertiliser application quantities per given area - Fertiliser application per given area is determined by various factors including: • the crop type. • the type of fertilizer. • the method of fertiliser application. • the fertility of the soil. • recommendations made by soil scientist after doing soil testing. • previous experience of the farmer on the field in question. Timing of fertilizer application Basal dressing • This is when fertiliser is applied before or at planting. 24 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 • Basal dressing can be done using compound and phosphatic fertilisers as well as organic manure. Top dressing • This is when fertiliser is applied after emergence, straight nitrogenous fertilisers are usually applied as top dressing. • Top dressing can be a single once off application or a series of split application. In split application, a fraction of the total fertiliser required is first applied and the remaining amount applied after a certain period. Calculations on fertilizer applications. Example 1: (N2011) a farmer applied 250kg of compound D fertilizer at a planting station and 200kg/ha Ammonium Nitrate for top dressing. Calculate the total amount of Nitrogen applied to the soil, given the following. Compound D- 8 %N 14 % P 7 % K Ammonium Nitrate- 34.5 % N Solution: Amount of nitrogen in compound D = 8/100 x 250 =20 kg of N Amount of N in Ammonium nitrate = 34.5/100 x 200 = 69 kg of N Total amount of N = 20 + 69 = 89 kg Example 2: (N 2011) A farmer intends to grow 2 ½ ha of a maize crop. If the recommended fertilizer application rate of top dressing is 200 kg / ha, how many 50 kg bags of top dressing are required? Show all working. Amount required = 2 ½ x 200 kg = 5/2 x 200 kg = 500kg/50kg = 10 bags ********************************************* Soil sampling  explain the importance of soil sampling  sample soil using at least one method Soil sampling 25 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - - Sampling is the selection of a small fraction of the whole so that the characteristics of the whole can be inferred from the fraction. Sampling is necessary because it reduces costs, space and time required to evaluate a certain characteristic about the whole population. In soil sampling it is impossible to take soil from the whole field so that the characteristics of that soil may be ascertained and as such only a fraction of the soil must be taken so that it can be taken to labs that do the analysis and these may be several hundreds of kilometers away. As such soil sampling should be governed by certain principles which shall be discussed here and these help to ensure that the results that you are going to get are going to reflect the properties of the whole field. However; before we look at these principles let us look at the need for soil sampling which may sound more or less the same like the introductory discussion. Need for soil sampling - It breaks bulkiness of the soil so that smaller amounts of soil can be used to determine characteristics about the whole field from which the soil was taken as such there is saving on space for storage, transportation and also time and monetary resources during the handling. - The sampled soil is used to determine the nutrient content of the soil so that the proper fertilizers can be applied at the right rates. - The sample is also used to determine the soil pH so that the right material can be used to adjust the pH, a farmer may use lime if the pH is too low or they may use acidic fertilizers if the pH is too high and it has to be brought down. - The sample may also be used to determine the physical characteristics of the field from which it has been taken and these may include the following; soil structure, texture, bulk density, particle density (these may help in the determination of water holding capacity, drainage and aeration) and colour among many other parameters. Principles of soil sampling - A soil sample should be representative of the whole field from which it was taken. As such the sample should be a composite one which is made up of several subsamples that would have been taken around the whole field not just from one corner. - A composite sample must be taken from each field for which recommendations are required. - Significant changes in a field must be sampled separately. By significant, it means the changes affect a large piece of the land and some of the changes include; changes in soil colour, texture, drainage, slope and vegetation among some of the parameters. If there is a large variation for areas in the same field then the samples will have to be taken separately. Minor variations in the field will have to be ignored since their impact is very negligible. - Uncharacteristic abnormalities have to be avoided and examples of such areas include; anthills, animal holes, ridges, compost sites, areas where fertilizer or manure was heaped and drain sites among many other areas which are not typical of large chunks of the field. 26 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - - - Each composite sample must be made up of at least ten subsamples no matter how small the field for the determination is. The number can only be increased not reduced, increase is more appropriate in larger pieces of land and in land which has just been ploughed. The subsamples must be taken randomly across the field without any bias as this may give false results. There are some methods that may be used to avoid this and these include completely random sampling across the field and zigzagging across connecting to corners moving diagonally and this must be done for all the corners. The sample must represent the full depth of the soil. All corrections that may be required are going to be done in the rooting zone and as such the soil has to be sampled at least to a depth of about 30cm which is the depth of the top soil. When samples are being taken for nitrogen determination, it will be best if the samples are going to be taken after the rains have stopped. If determinations are made during the rains, there may be further loss of the nitrogen during the season and whatever corrections were made may be lower than the actual requirement. If samples are required for pH determination, then the samples can be taken anytime since the hydrogen ions which cause or determine acidity are not easily leached since they are tightly held to soil particles. Methods of soil sampling Spade method - Dig a V-shaped hole to plough depth which is about 30cm. Do not brush away litter or loose soil on the surface. Cut a uniform slice of soil along one arm of the V shape taking proper care not loose any of the soil especially the surface soil. This is going to be done at each sub-sampling point. - This method only works where the ground is firm, where it is loose like in recently ploughed lands the method is not really suitable since a lot of the soil from the surface is going to fall back into the hole and the results may not be reflective of the true properties of the soil in question. The trowel method - A normal garden trowel is used to gather subsamples in recently ploughed lands. The setback with a trowel is that the representativeness of the subsample is reduced since its effectiveness is reduced with increasing depth. - To try and counter this you are supposed to increase the number of subsamples that are taken per piece of land over the recommended 10. - The method therefore becomes rather tedious and even so the results will not be really representative, it will require someone good at the technique. Auger method - This is the most rapid method and it is more efficient in taking samples that are more representative of the soil depth. - The method can be used by almost anyone who is able bodied since room for mistakes is reduced. - The equipment has a screwing effect and as it is screwed into the soil it will be augering soil into a collection bucket packing it tightly as it does so. 27 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - When the bucket is full the soil is discarded in a collection container as a subsample. This method cannot be used in very wet lands since the soil can get sticky therby preventing the proper augering of the soil. In soils which are very loose, the soil will not remain in the bucket, it will be more suitable to use the trowel method. In very dry lands it will be almost impossible to screw the auger into the soil, it will be more suitable to use the spade method. - The augers come in different sizes which vary with the diameter of the bucket. Preparing the samples for analysis - When all the subsamples have been collected in one container, there is going to be some thorough mixing of all the subsamples to ensure the representativeness of the composite sample which is made up of all the subsamples. - The composite sample is allowed to dry if it has some moisture in it and the drying should be natural, artificial drying is known to destroy some components which are of significance. - When the soil is ready, about a kilogram of soil is drawn from the composite sample and packed in a proper package which can have the following information labeled on it; name of farmer, name of field, date sampled and purpose of sampling. - This prepared pack is send for analysis at proper labs which may be private or public. The private laboratories include those at fertilizer companies like ZFC and Windmill and also at the Zimbabwe Sugar Association Experimentation Station in Chiredzi. - There is also the quasi-government Tobacco Research Board Kutsaga Station and the soil science and chemistry sections of institutions of higher learning like universities and polytechnic colleges. - Normally there is a fee to be paid for the service rendered. Fertilizer companies normally do pH determinations for free but they will charge you for nutrient content determinations and the recommendations. - It is important to note here that fertilizer companies normally make recommendations using their product which to me becomes easier for the farmer rather than being given numbers for nutrient requirements which may be difficult for the farmer to formulate on farm. Precautions - All implements and all containers that are going to be used for the exercise must be clean and free from chemicals that may alter the actual chemical contents of the soil e.g. used fertilizer sacks should not be used. - Avoid the peripheries of the field as these normally may have too much or too little fertilizer applied to them. 28 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* Soil pH and liming       describe how soils are tested for pH discuss the influence of soil pH describe methods of correcting soil pH identify types of lime explain the importance of liming materials explain the difference between lime and fertiliser interpret the significance of pH values Soil pH and Liming - Soil pH is the measure of acidity or alkalinity of the soil, soils below pH 7 are acidic and those above pH 7 are alkaline Testing soil for pH - Materials- universal indicator or pH paper, distilled water, test tubes, and soil samples. 1. Place soil in the test tube to a height of 2cm. Add distilled water to almost fill the test tube. 2. Add a few drops of universal indicator solution and shake well. 3. Leave the test tube to stand until the solution is clear. 4. Read off the pH on the universal indicator colour chat. - If using indicator paper, dip the pH paper into the solution once it has settled. Influence of soil pH - soil pH affects the availability of important plant nutrients, under extremes of both acidity and alkalinity most nutrients are not available for use by plants. - nitrogen fixing bacteria and bacteria that are responsible for decomposition of organic matter function best at a pH range of about 6.5 to 7.5. - plant cells die and there is tissue necrosis under very acidic and very alkaline conditions, this results in the death of plants. Methods of correcting soil pH - soil acidity can be corrected by adding lime. Lime is any compound of calcium and/or magnesium that is used to correct soil pH and nutritional disorders. Types of lime - quick lime (calcium oxide). - dolomitic (calcium magnesium carbonate), this type or lime contains both calcium and magnesium. - hydrated or slaked lime (calcium hydroxide). - ground limestone/calcitic lime (calcium carbonate) Importance of liming materials - Liming reduces acidity to a point where most plant nutrients are available. - it adds nutrients calcium (for cell wall formation), magnesium (chlorophyll formation). 29 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - calcium flocculates soil particles into a crumb structure thereby improving soil structure. lime also increases nodulation of legumes thereby increases nitrogen fixation. soil microorganism activity increases. The difference between lime and fertiliser - Lime is mainly applied as a soil conditioner (raises soil pH) while fertiliser supplies plant nutrients. ********************************************* Nitrogen cycle  describe the nitrogen cycle with the aid of a diagram Nitrogen cycle - Atmospheric nitrogen is fixed into soil by rhizobium bacteria Rhizobium bacteria stay in leguminous plants, for example groundnuts. Bacteria get carbohydrates from legumes and they supply legumes with nitrogen. - The nitrogen cycle in plants can best be described by a diagram as below: Nitrogen gas in the atmosphere De-nitrification N 2 fixation by legumes bacteria) Nitrogen in plant protein death Nitrates Decay ( Nitrobacter ) Nitrification Feeding Animal protein Ammonification nitrosomonocus Nitrites Explanation of the diagram - Nitrogen fixation: Atmospheric nitrogen is fixed into the soil by the bacteria called rhizobium, found in root nodules of all legumes. 30 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - The nitrogen in plant protein is taken in by animals through feeding processes. The animals contribute animal protein. Plants and animals die and decay to form ammonium compounds. The bacteria called nitrosomonas and nitrosococcus act on ammonium compound to form nitrites. Nitrites are not used by plants because they are poisonous. The Bacteria called nitrobacterium acts on nitrites to convert them intro nitrates which are usable by plants. The denitrifying bacteria act on nitrates to obtain oxygen for respiration. The nitrogen released from nitrates is further released into the atmosphere. A-Nitrogen fixation by legumes B-Nitrification-Nitrobacter, nitrifying bacteria C-De-nitrification-de-nitrifying bacteria Explain the functions of the following bacteria in the nitrogen cycle: (i) Rhizobium bacteria, [2]  Fixes nitrogen from the air; in root nodules; of legumes; which is then used by plants. (ii) nitrifying bacteria, [2]  Converts ammonium compounds; from decayed plants/ animal; to nitrutes; then to nitrates. (iii) denitrifying bacteria. [2]  Converts nitrates to nitrites; then to nitrogen gas; which is lost into the atmosphere. How nitrogen is lost from the soil. List 3 processes through which nitrogen is lost from the soil. [3] The following processes facilitate the loss of nitrogen from the soil: - It is lost through:  Leaching: This is the washing away of nutrients by water infiltrating the soil. 31 GWANZURA.R. guide 2020-0773266377 / 0717 558 917      Plant up take: Plants use up nutrients as they grow. Soil erosion: This is the washing of top soil by water and wind. Volitization: This refers to loss of nitrogen in the form of gas. Burning of residues of crops: This deprives the soil of the manure that would have formed from rotting husks. Dentrification: It is a process where denitrifying bacteria breaks down nitrates into nitrites resulting in nitrogen gas going into the atmosphere. November 1996 b). Explain the importance of legumes in Agriculture Possible Answer - rich in proteins, useful as hay, improve pastures - fix nitrogen into the soil/ improve fertility, - reduce use of nitrogenous fertilizers / costs November 1995 2a). Explain the importance of each of the following in the nitrogen cycle. i). lightning ii). nitrifying bacteria iii). Nitrogen – fixing bacteria b). State three methods which can be used to improved quality of livestock. c). How can excessive irrigation be harmful to crops? Possible Answers a). Explain the importance of each of the following terms in the nitrogen cycle. Term Explanation Lightning converts atmosphere nitrogen into nitrates Nitrifying bacteria converts ammonium carbonate to nitrous acid which reacts with lime to form nitrates Nitrites are changed to nitrates by nitrobacter Nitrogen fixing bacteria in the soil convert nitrogen from the air into Bacteria nitrogen compound that can be used by the plant b). State three methods which can be used to improve quality of livestock. -cross breeding livestock -selection of cows and bulls -improve nutrition c). How can excessive irrigation be harmful to crops? - Too much water will cause erosion, water logging and will increase incidence of pests, diseases and weeds. ********************************************* SUB TOPIC: SOIL EROSION AND CONSERVATION ********************************************* Conservation methods and structures  describe methods of soil conservation on arable and grazing lands  describe the construction of basic conservation structures to standard dimensions 32 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 SOIL EROSION AND CONSERVATION - Top soil contains humus and is very important for agricultural activities. The loss of top soil makes the land unproductive for agriculture. - soils are more prone to erosion when they are sandy, lacking humus and having no vegetative cover. - areas with gradients that are steep experience high rates of erosion due to high speeds of runoff. - Farmers’ practices may encourage or reduce levels of erosion. Conservation methods and structures in arable and grazing lands - these are practices meant to conserve natural resources by utilizing them beneficially without compromising their quality and availability to future generations. Cultural methods 1.Early planting - Early planting enables crops to establish a canopy before onset of rains. Leaf canopy will break the impact of raindrops reducing splash erosion and encouraging infiltration of water into the soil. 2.Intercropping - Intercropping or planting of crops of different growth habits including cover crops such as pumpkins reduces soil erosion, thereby conserving the soil. 3.Crop rotation - Crop rotation with broad leaved plants included in rotations conserves soil by reducing soil erosion. 4.Mulching - Mulching introduces soil cover which encourages infiltration and reduces erosion of top soil by surface runoff. 5.Paddocking - Paddocking or rotational grazing discourages over grazing and maintains good soil cover which reduces erosion by allowing ample time of grass regeneration between animal grazes. 6.Correct stocking rate - Farmers should not keep more livestock than their families can sustain as this results in overgrazing leaving soil bare and unprotected from erosion. 7.Grass planting - Planting grasses creates soil cover which protects soil from erosion, reducing runoff. 8.Destocking - Reducing number of livestock when the carrying capacity of land has been exceeded. 33 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 9.Correct fertiliser application - Addition of organic matter.This ,improves infiltration of water whilst reducing runoff which washes away top soil. 10.Good soil cover - Avoid burning of grasses to maintain good soil cover Advantages of cultural methods of soil conservation • • Cultural methods are cheap They are easy to carry out on small lands • • They do not reduce arable lands These methods increase yields Disadvantages of cultural methods of conservation • • • They take time to establish Cultural methods introduce weeds The methods can fail easily Mechanical soil conservation methods - To control speed of runoff and allow for improved infiltration in arable lands that are slopy, farmers should construct the following features: 1.Storm drains - These are structures dug at the upper land of the field to catch and divert storm water to water ways. Storm drains reduce high rates of erosion through uncontrolled runoff from heavy rains. 2.Contour ridges - Contour ridges reduce runoff speed in arable lands which washes away soil loosened by cultivation. These are constructed inside the field to collect surface runoff and discharge this water safely to water ways. 34 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 3.Water ways - Water ways control water paths minimizing erosion of top soil. 4.Terraces - Terraces are levelled perches of land constructed on sloping land to reduce gradient of slope and to enable cropping with reduced run off and soil erosion. 5.Tied ridges - These are ridges made in between crops forming furrow like structures with breaks made of soil in between to stop continuous flow of water between planted crop rows. These ridges encourage infiltration and reduces soil erosion. ********************************************* SUB TOPIC: WATER LOSS AND SOIL DRAINAGE ********************************************* Drainage and water logging  describe drainage and water logging  explain the effects of water logged soils on crop growth  describe methods of improving drainage Drainage: this refers to the movement of water through soil particles. Soils with large particles have good drainage while those with closely packed particles have poor drainage. Poor drainage leads to water logging. Water logging: when water is applied to the soil, it fills or occupies the air spaces. When all the air spaces are filled by water the soil will be saturated. When saturation of air spaces persists the soil becomes waterlogged. Effects of waterlogged soils on crop growth - as the soil becomes waterlogged all the air from the soil is removed resulting in lack of oxygen for roots and micro- organisms. - the roots will not be able to respire resulting in death of plants 35 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - aerobic micro- organisms will not be able to survive resulting in reduced microbial activity in the soil and subsequently low fertility in the soil consequently because of low fertility nutrient release to plants is reduced fungal diseases will be on the increase causing plants to be affected and yields being reduced Methods of improving drainage 1. Surface drainage - the simplest method is by digging single open drains or ditches. These are channels which drain water to a river or waterway. - ditches can be 1-2m deep and 50-100m apart, depending on soil type. Clay soils need shallow drains which are close together, while sand soils need deeper drains which are far apart. 2. Sub-surface or internal drainage - this is the removal of excess water by downward flow through the soil. - However, this has the effect of permanently lowering the water table. -sub-surface drainage is accomplished by: o digging open ditches deep enough or down to the impervious layer ii) the use of sub-surface pipe drains- these are clay or plastic pipes laid in ditches and covered. The pipes are perforated and water enters through the holes - *on a small scale beds can be raised 20-30cm above the ground and this can help drain water - however, as the excess water moves down the soil profile it takes with it dissolved plant nutrients such as nitrates, and these are lost from the field’s soil system together with the water as it enters the pipe drains and gets discharged from the field. - the loss of dissolved nutrients due to excessive drainage, to horizons beyond the reach of roots is called LEACHING. ********************************************* Leaching  explain the causes of leaching in arable lands  Experimenting to show leaching levels of different soils  explain the effects of drainage on loss of plant nutrients  describe methods of controlling leaching in arable lands leaching - refers to the loss of water-soluble plant nutrients from the soil, due to rain and irrigation. Causes of leaching on arable land - leaching is caused by excess water on the land surface and in the soil which originates from excess rainfall; over irrigation; seepage from dams, canals and ditches - alternatively, it may come into the area through surface or sub-surface flow from other areas where there is excess rainfall or irrigation 36 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Effects of drainage on loss of plant nutrients - leaching results in plants losing essential nutrients such as nitrogen. Due to leaching, soluble nutrients like nitrogen need to be split applied especially in areas with high rainfall and highly drained soils - leaching is beneficial at times as it helps move soluble nutrients like nitrogen applied as top dressing on the soil surface reach the plant roots Methods of controlling leaching in arable lands - it is difficult to control leaching in the field. Where possible, large quantities of organic manure should be applied to sandy soil to improve soil structure and thus reduce drainage - ant hill soil can be applied in the field to improve the clay content of the soil and thus reduce drainage ********************************************* SUB TOPIC: WATER CONSERVATION ********************************************* Rain water harvesting and storage  describe methods of harvesting and storing water  describe different ground water sources Methods of harvesting and storing water Rain water harvesting - rain water can be collected using various methods during the rainy season. The collected water is stored in dams, tanks and reservoirs for use later during the dry season. - rain water can be harvested through the use of gutters and dwalas or domes. Water harvested through these methods can be used to irrigate small areas around homesteads and gardens. 1. Roofs and gutters - rainwater that falls on roofs flows downwards to the edges of the roof where instead of dropping to the ground the water drops into the gutters that convey the water into storage tanks. 2. Domes and dwalas - large granite outcrops which may be dome shaped or low lying with curved surfaces are used to harness rain water. peripheral concrete structures are built around the dome or dwalas and canals to channel water into storage tanks or dams. a) Rain water storage 1. Dams 37 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - soil surface runoff from rainfall collects in streams and streams supply rivers. Small rivers feed into bigger rivers dams are structures that are built mostly on river gorges for the purpose of collecting runoff that collects in streams and rivers. 2. Weirs - these are concrete or brickwork structures that are small imitations of dams built on rock surfaces to temporarily store water for irrigation. weirs may also collect flood water from the rains GROUND WATER SOURCES - ground water sources are crucial in supplying water for farming during dry spells. The ground water sources can be natural or artificial. Examples of ground water sources are: 1. Boreholes 2. Lakes 3. Dams 4. Wells 5. Rivers/ Streams ********************************************* Water pollution  explain causes of water pollution  describe the effects of water pollution on agricultural production  discuss ways of reducing water pollution Water pollution - It is the contamination of water sources by chemicals, fertilizers, detergents and sewage Causes of water pollution  Chemicals and fertilizers from industries. They can be applied to crops, then washed into the soil, to the rivers and dams there by posing a health hazard.  Sewage deposited into water sources Effects of water pollution  Affects aquatic life e.g fish.  Leads to diseases e.g bilharziasis  Leads to Eutrophication (overgrowth of microscopic aquatic plants and green algae which absorb oxygen for fish and other animals, leading to massive death and upsetting the ecosystem. Water treatment Common methods of water treatment are:  Water settling 38 GWANZURA.R. guide 2020-0773266377 / 0717 558 917   By filtration By chlorination ********************************************* Water legislation     discuss water use legislation discuss water management in Zimbabwe Management of national water (ZINWA) Identification of water bodies Water legislation. - This refers to the law regulating the use of water in the country. In Zimbabwe, water use is controlled through the Water Act of 1976 whose purposes are: (i) The prevention of water pollution (ii) All irrigation systems should be approved by the state (iii) Makes sure that extraction of underground water is controlled by the state. (iv) Right to use public water is granted by the state (v) Apply for water rights before setting up irrigation projects. ********************************************* SUB TOPIC: IRRIGATION ********************************************* Methods and types of irrigation  describe methods of irrigation  explain different types of irrigation  explain the advantages and disadvantages of each method of irrigation IRRIGATION - this is the artificial application of water to the soil to meet the crop water requirements. - irrigation is usually done to supplement rainfall shortages and during prolonged dry spells. Methods of irrigation - There are basically three main methods of irrigating crops namely; 1. Surface / flood irrigation 2. Overhead /sprinkler irrigation 3. Drip irrigation 39 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Surface/Flood irrigation - this is a method of irrigation that moves water over the soil surface through canals and furrows. Siphons can also be used to move water from canals into the fields. - types of surface irrigation methods are : i) ridge and furrow irrigation ii) border irrigation method iii) basin irrigation Advantages of surface / flood irrigation • Deep irrigation can be achieved • It has low operation costs once land has been levelled • Volumes of water can be measured accurately Disadvantages of surface irrigation methods • can result in soil erosion • uneven wetting if soil is not properly levelled • large volumes of water are required • productive land is lost to canals • changes in soil types along the water path may affect the efficiency of the method • not suitable for sloppy land Overhead irrigation method - this system of irrigation imitates rainfall. Water is pumped at high pressure usually via aluminium pipes. The water is then delivered via nozzles in a form of a spray. - types of overhead methods : i) sprinkler irrigation ii) centre pivot irrigation iii) drag hose irrigation Advantages of overhead irrigation • can be used on all terrain without any need of levelling the land • can also be applied with fertilisers as fertigation • cools the plants • nocturnal/night irrigation is possible Disadvantages of overhead irrigation • may wash off chemicals before they are effective • can be affected by wind • • • operational costs can be high such as diesel or electricity for pumping, servicing of equipment and repairs operation of some equipment such as the centre pivot may require skilled labour evaporation losses can be high 40 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Drip irrigation - this is a system of pipe networks set up in a predetermined pattern that supplies water at low pressure to localized stations - the water is discharged at each planting station adjacent to the palnt or as a subsurface network that discharges water at the root zone - types of drip irrigation: i) drip irrigation ii) micro jets Advantages of drip irrigation system - less energy is required for pumping - less evaporation loss - does not cause erosion - effective in weed control as weeds are at a competitive disadvantage as they are not supplied with moisture and nutrients - offers improved fertilizer placement - less labour requirement - reduced disease incidence Disadvantages of drip irrigation - expensive to install - the pipes can be blocked - requires clean filtered water - pipe network may hinder other operations in the field - plant root development is restricted - requires careful and skilled management ********************************************* Choice of an irrigation system  discuss the factors affecting choice of an irrigation system  Demonstrating different methods of irrigation  Designing an irrigation system Choice of an irrigation system - Choice of an irrigation system is determined by many factors: 1.Soil type - The choice of an irrigation method depends on soil type, for example, flood irrigation methods cannot be used on sandy soils. 2.Slope of the land - The slope of the land also influences choosing of an irrigation method. Flood irrigation cannot be used on sloping land. Sprinkler irrigation will be most ideal for sloping land. 3.Amount of water in the source of water 41 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Flood irrigation methods cannot be used with little volumes of water. 4.Availability of power - Availability of power affects the choice of irrigation system. Offgrid areas may use diesel pumps or rely on methods using alternative sources of power other than electricity. ********************************************* Irrigation equipment   identify irrigation equipment describe the structures and functions of irrigation equipment ********************************************* TOPIC 3: CROP HUSBANDRY ********************************************* SUB TOPIC: STRUCTURE OF FLOWERING PLANTS ********************************************* Plant anatomy and physiology  identify parts of the internal structure of a root, stem and leaf  explain functions of tissues in a root, stem and leaf Structure of a root - Root tip is covered by a root cap to protect it from physical damage as it pushes through the soil and therefore the root is able to penetrate a good depth of the soil absorbing nutrients - Root has hairs which are elongated cells, with a thin cellulose cell wall which enables ions to diffuse short distances into the cell. - Numerous root hairs grow amongst soil particles to provide a very large surface area for the absortion of water and nutrients - When root hair die, they are replaced by new ones. 42 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Functions of the parts of a root. Part Epidermis Cortex Cambrium Phloem Xylem Root hairs Function Prevents excessive water loss and entry by bacteria For extra xylem and phloem vessels Produces xylem and phloem vessels Feature Thin,waxy Transport food (sucrose) to all parts of the plant Transports water and mineral salts from roots to all plant parts Absorb water from and nutrients from the soil Have parenchyma cells Composes of undifferentiated cells Have parallel rows of undifferentiated cells Dead and lignified Large surface area, delicate Basic functions of a root system ▪ Provides physical support to the plant (anchorage) ▪ Absorption of water from soil through osmosis ▪ Uptake of plant minerals through diffusion and active transport ▪ Act as food storage organs for some plants Structure of the stem - - The plant stem performs the following essential functions: • Supports the plant and leaves • Carries water and food in vascular bundles • Photosynthesis occurs in new green stems The structure of the stem allows it to perform these functions efficiently. The diagram below show the internal stem structure of a typical dicotyledonous plant 43 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 epidermis cortex phloem cambium pith xylem phloem - cambium xylem Pith- it is the large central area for storage of food and support. It may be absent in older plants (they’re hollow) Cambium-it is found as a circle around inner stem and outer surface. Forms woody secondary tissue for support Cortex- it is composed of various packed cells to give young plants strength and flexibility. It is a storage area between the cambium and epidermis Epidermis-thin layer of skin cells. It provides protection and it may be absent replaced by bark Xylem-water conduction up Phloem-sap (organic molecules) conduction usually down to the roots Structure of the leaf - - Most leaves are covered by a waxy cuticle on the outside which is waterproof and prevents the plant from losing too much water through leaves. It also protects the leaf. On the surface of most leaves there are veins which transport substances to and from the leaf. 44 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Leaves are attached to the stem by a petiole that can change position of the leaf so that it always receives as much sunlight as possible for photosynthesis. Most leaves are thin and flat with a large surface area(lamina) and the edge is called the margin Cuticle layer:- It is a waxy layer on top of epidermis. It is a waterproof and therefore reduces the loss of water from the leaves and also prevents entry of pathogens. - Palisade layer/mesophyll- : main organ of food production. The cells contain a lot of chloroplast. - Spongy layer :- have got a lot of air spaces and is important for gaseous exchange. - Vascular bundle-: contains the xylem and phloem vessels. - Xylem vessels-carries water required for photosynthesis. - Phloem vessels- carry away soluble food to other parts of the plant. THE CROSS-SECTIONAL STRUCTURE OF A LEAF - Much of the photosynthesis takes place in the palisade cells. The spongy layer has a lot of air spaces to allow easy diffusion of gases through the leaf. Gases enter and leave the leaf through microscopic holes called stomata. The cuticle is waterproof so as to prevent excessive water-loss Adaptations of the Leaf for Photosynthesis - Large surface area to trap light. Thin leaf to allow light through and a short diffusion for carbon dioxide. Presents of stomata on the underneath of the leaf to allow gaseous exchange. Spongy layer which creates air spaces to allow carbon dioxide to enter through. Chlorophyll to attract or trap sunlight. Venation (veins) to carry water into the leaf and soluble food out of the leaf ********************************************* 45 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 SUB TOPIC: PLANT PROCESSES ********************************************* Water and nutrient uptake  describe the absorption of water by plants through osmosis  explain nutrient absorption by roots through active uptake  describe absorption of water by seeds All the chemicals reacting in the cells need to get in and out either by a Passive process: This doesn’t need energy e.g. osmosis and diffusion or an active process: one that requires energy e.g. active transport. Diffusion: - It is the movement of a molecule from a reign of high concentration to a reign of low concentration down the concentration gradient which is the difference in concentration of the substance, the greater the difference the higher the rate of diffusion. - The rate of diffusion depends on : • Concentration gradient • Temperature • Size of molecule • Surface area • Permeability of membrane Osmosis - is the movement of particles from a region of higher concentration (abundant) to a region of lower concentration (less abundant) through a partially permeable membrane. - It is the movement of a liquid from a region of higher concentration to a region of lower concentration through a semi- permeable membrane. Importance of osmosis  It enables plants to absorb water and nutrients from the soil. Imbibition: It is the absorption of water by the seed so as to effect germination. Active transport: - It is the uptake of substances from a reign of low concentration to a reign of high concentration, against the concentration gradient requiring protein carriers. 46 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* Transpiration     discuss the role of transpiration stream describe the role of stomata explain how wilting occurs outline factors affecting rate of transpiration Transpiration stream - loss of water from plant leaves creates a pulling force which causes water with dissolved minerals to move upwards from the soil through the stem. Both water and mineral salts are required by the plant. - Forces of adhesion, cohesion and tension between the water molecules and also walls of the xylem allows this effect. - The transpiration stream allows for the movement of water up the plant that transpiration can occur. - Transpiration is the loss of water in the form of water vapour by plants through the stomata. Stomata. - Are very numerous on the lower epidermis. On the upper side of the leaf they are fewer. - Usually the stomata are open during the day and closed during night-time. - A stoma consists of a pore which is bound on both sides by a kidney-shaped guard cell. - The guard cells contain chloroplasts while the other epidermal cells don't. The inner wall of each guard cell is thicker than the outer wall. Opening and closing of stomata. - When a guard cell becomes TURGID (this means that the internal pressure or TURGOR increases), by the intake of water (through osmosis), its outer wall is pushed outwards and the thick inner wall bulges in the same direction. - As both guard cells work in the same way, but opposite directions, the pore opens. 47 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - The diffusion of gases into and out of the leaf is regulated by the stomata. In most plants gaseous exchange occurs during the day and stops during the night. Wilting in plants - Wilting is loss of turgidity by plant cells causing the plant to drop. It occurs when the rate of water loss from the plant is higher than the rate of water uptake by the plant. Water from the mesophyll cells evaporates into the sub-stomatal air space and diffuses out into the atmosphere through the stomata. Temporary wilting means that plant cells have the ability to regain their turgidity after adsorbing enough moisture. Permanent wilting is the severe loss of water by plant cells that they can no longer regain their turgidity even if water is now available. Drought resistant crops have the ability to minimize water loss through transpiration even under dry conditions. This is achieved by partial closer of stomata. Factors affecting transpiration - - - Light intensity: -Plants transpire more rapidly in the light than in the dark. This is largely because light stimulates the opening of the stomata. An increase in light intensity results in the increase of rate of transpiration due to an increase in stomata opening. This is a problem for some plants as they may lose water during the day and wilt Temperature: -Plants transpire faster at higher temperatures; this is because the rate of evaporation increases with temperature. At 30 degrees a leaf may transpire three times as fast as it does at 20 degrees. Temperature also reduces air humidity, so transpiration increases Humidity: - Humidity means a higher water potential (concentration) in the air, so the lower a water concentration gradient between the leaf and the air, so less evaporation. Humidity can be defined as the relative amount of water in the atmosphere. If the air is dry then the diffusion gradient would be greater from the plant to the atmosphere. There would be an increase in the diffusion of water vapour out of the stomata and into the atmosphere. If the air is humid (containing a lot of water) then the opposite would be true, and very little water would diffuse out of the atmosphere 48 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - - Wind: - Very little wind means water vapour on the leaf is not swept away and this result in an increase in humidity; there by resulting in lower rate of transpiration. When there is a breeze humid air is carried away and an increase in transpiration is experienced Water supply: - If the plant has very little water available, it will close its stomata. This will of course cause a decrease in the rate of transpiration. If absorption of water by the roots fails to keep up with the rate of transpiration, loss of turgor occurs and the stomata close; this reduces transpiration and as well as photosynthesis. If the loss of turgor extends to the rest of the leaf and stem, the plant will wilt Leaf surface area: - the broader the leaf surface area the higher the rate of transpiration due to a higher number of stomata. Smaller leaf surface area is associated with lower rates of transpiration. November 1996 c). Explain how plants use water Possible Answers - used in transpiration to cool the plants - combines with CO2 in the presence of light to produce carbohydrates / oxygen - a solvent for nutrients/ translocation - a medium for all chemical process in the plant - Used in germination - Major component of plant tissue ********************************************* Photosynthesis  describe how plants photosynthesise  state the chemical and word equation for photosynthesis Photosynthesis - It is the process by which green plants manufacture their own food They trap sunlight using chlorophyll and convert it to glucose using water & oxygen Oxygen is released as a by product Equation Chlorophyll Carbon dioxide + water Carbohydrates + Oxygen Sunlight 49 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Raw materials of Photosynthesis 1. Carbon dioxide 2. Water Products of Photosynthesis 1. Carbohydrates 2. Oxygen Conditions necessary 1. Chlorophyll 2. Sunlight Sources of raw materials for photosynthesis Water – it is sucked from the soil by the roots (osmosis) & transported up the stem to the leaf where it is used Carbon dioxide– it moves into the leaf from the air by the process of diffusion through the stomata (tinny holes under the leaf The Process: - How photosynthesis occurs - Carbon dioxide and water enter into leaf cells Chloroplasts in the chlorophyll traps sunlight energy. The light energy is s used to split water into hydrogen and oxygen. The oxygen escapes from the leaf to the atmosphere as a by-product. The hydrogen reacts with carbon dioxide to form carbohydrates. Factors affecting Photosynthesis The following list provides factors that affect the process of photosynthesis.  Light intensity: The amount of light reaching leaves at a given time.  Carbon dioxide concentration: Refers to the extent or amount of carbon dioxide in the atmosphere.  Presence of chlorophyll: Refers to the green colour in plants which facilitates photosynthesis.  Carbohydrates: Refers to the energy released during photosynthesis in plants. Describe how leaves are adapted to the process of photosynthesis. [5]       Palisade layer: dense contain many chloroplasts; Spongy mesophyll: many intercellular spaces for gases exchange; Many stomata: allow gaseous exchange; Broad lamina: trap sunlight; Thin lamina: gases travel short distance/ allow light to penetrate all layers of the leaf; Leaf vein: water available from vein. 50 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* Translocation and food storage  explain the process of translocation  identify plant food storage organs  state the nature of food stored by plants Translocation - It is the movement of manufactured plant food to the storage organs, for example, roots, stems, seeds, leaves etc. Food storage organs  Tubers- (store most sugars)  roots (store sugars)  leaves  fruits  Seeds- (Cereals and legumes store their food in seeds)  (Proteins, Fats/oils and vitamins-stored in seeds) Importance of food storage Food storage helps in the movement of food from point of production to point of storage for future use. ********************************************* Respiration      state the word and chemical equation for aerobic respiration distinguish between aerobic and anaerobic respiration identify sites of respiration describe the importance of respiration explain the differences between photosynthesis and respiration Respiration - Refers to the breakdown of carbohydrates during the presence of oxygen and carbon dioxide is released. - State the word equation for aerobic respiration. [1] - C6 H12 O6 +6O2 6CO2 + 6H2 O + Energy. The word equation for respiration is, Carbohydrates + Oxygen Carbon dioxide + Water + Energy Forms of respiration Aerobic Respiration 51 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - It occurs when oxygen is available and is a source of energy for growth and other plant processes. Occurs in all living organisms. Anaerobic Respiration - Does not use oxygen to breakdown food. - Little energy is released. - Used to brew beer, to ferment sugars to alcohol. Differences between photosynthesis and respiration Photosynthesis  Occurs only in light in green cells of plants  Carbon dioxide is used and oxygen released  Light energy is built up  Plants gain weight  Chlorophyll is used Respiration  Occurs all times in all living cells  Oxygen used, carbon dioxide is produced  Energy is released  Plant losses weight  Chlorophyll not used Explain the importance of respiration in plant growth. [3]  Enables plants to get energy for growth;  Allow the exchange of gases; for the development of roots; November 1997 Explain the differences between a). respiration and photosynthesis - respiration: oxygen used to provide energy in cell - carbon dioxide and water are produced - photosynthesis: carbon dioxide and water used to produce food and oxygen in chloroplasts, respiration takes place in both animals and plants while photosynthesis occurs in plants only. Respiration C6H12O6 + 6O2 Sugar + Oxygen Photosynthesis 6CO2 + H2O Carbon Dioxide + Water 6CO2 + 6H2O + Energy Carbon Dioxide + Water C6H2O6 + 6O2 Sugar + Oxygen ********************************************* Plant tropisms    describe each of the tropisms Plant tropisms Responses to light, touch, gravity and water demonstrate the responses of plant parts to tropisms 52 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  evaluate the importance of plant tropisms Tropism - Is a response shown by a plant to an external growth stimulus - The response by a plant to a stimulus can be negative or positive. - A negative response means plant growth takes place in the direction opposite that of the external stimulus. - A positive response means plant growth takes place in the direction of the stimulus. - Hydrotropism is the response of the plant to water. Plant roots grow toward moisture. Hydrotropism enables roots to take up dissolved plant nutrients. Plant roots show positive hydrotropism but shoots shows negative hydrotropism. - Phototropism is the plants response to light. The shoot of the plant grows towards light. This enables the plant to absorb light for photosynthesis.in addition phototropism enables the shoot to be exposed to the atmosphere for gaseous exchange to take place. - Geotropism is the response of a plant to the force of gravity. Roots grow downwards due to the force of gravity. Geotropism enables roots to penetrate the soil and this gives the plant physical support (anchorage) . 53 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Haptotropism - This is the response of plant to touch, usually displayed by climbing plants. They get support and they grow tightly around the supporting plant - Importance of Haptotropism -It enables climbing plants to grow upwards because they cannot stand on their own. ********************************************* SUB TOPIC: CROP IMPROVEMENT ********************************************* Crop breeding (Maize)      state the importance of crop breeding explain heterosis differentiate between open pollination and controlled pollination state the three types of crop hybrids describe the production of single, double and three way hybrids importance of crop breeding - produce new high yielding crop cultivars - produce cultivars which are tolerant to pest and diseases - produce cultivars which are suited to the climatic conditions experienced in an area - produce cultivars which produce yields of superior quality to the existing ones. Cultivars may be superior in terms of nutrient content, storage quality, resistance to herbicides. E.tc. Heterosis (hybrid vigour) - it is superiority shown by a hybrid over both parents in certain important characteristics - lets take an example of two different maize cultivars, A and B. 54 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 -  Cultivar A produces high yields but has low resistance to diseases.  Cultivar B produces low yields but has high resistance to diseases. Cross pollinating cultivar A with Cultivar B may result in a hybrid which produces high yields and has good resistance to diseases. The hybrid is said to show heterosis or hybrid vigour because of its superiority to both parents. Open pollination - It is the pollination which takes place naturally through pollinating agents such as wind and insects which carry pollen from unknown sources. Controlled pollination - It is pollination which takes place between selected parent plants. - The production of different maize hybrids is achieved through controlled pollination. Types of crop hybrids 1. Single hybrid 2. Double hybrid 3. 3-way hybrid Hybrid production - 2 different types of maize plants with desired qualities are planted in the same field. - The field must be isolated to prevent pollination from unknown sources. - One type of plant is allowed to tassel and produce pollen and this is called the male or pollen parent. - The second type, the female or cob parent is only allowed to silk and its tassel is removed. Detasseling is done to prevent self – pollination. - The two types of plants then cross pollinate to produce a hybrid. Single cross or single hybrid: - hybrid obtained from a cross between two inbred-lines - these are high yielding, but have limited adaptability inbred line A x (seed/cob parent) inbred line B (pollen parent) single hybrid cultivar (AB) Double cross hybrids / double hybrids: - obtained from a cross between two single crosses. single hybrid (AB) x single hybrid (CD) (seed/cob parent) (pollen parent) double hybrid cross 55 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 3- way hybrids/crosses - obtained from a cross between a single hybrid cross and an inbred line - have wide adaptability; medium level yields but can reach 10t/ha with optimum conditions and top management. single hybrid cross x (seed/cob parent) inbred line (pollen parent) three-way hybrid Advantages of using hybrid seed - high yields are obtained because parents with good qualities are used to produce hybrid seed. - There is good resistance to pest and diseases. - There is good adaptation to the local environmental conditions. - The quality of yield is high. Disadvantages of using hybrid seed - Only the first generation (F1) shows hybrid vigour. - They are expensive to produce. ********************************************* SUB TOPIC: CROP PRODUCTION ********************************************* Land preparation     state reasons for land preparation describe steps taken during land preparation describe primary and secondary tillage methods describe conservation or minimum tillage techniques Reasons for land preparation - to provide the necessary soil conditions which enhance the successful establishment of a selected crop. - To improve the aeration of the soil. - To help destroy soil weeds, insect pests and diseases. - To prepare land to enable the establishment of surface irrigation. - To add in erosion control - To help conserve soil moisture - To incorporate crop residues - To loosen the soil and allow freedom of root development. - To make a seedbed for successful germination and establishment of a crop. - To increase rainfall infiltration into the soil - To level the field - To break soil pans and soil caps 56 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Steps taken during land preparation 1. Land clearing of large rocks and vegetation by stumping using caterpillars or axes and mattocks. When land is not too rocky, clearing involves the removal of rocks, debris and vegetation. 2. Collect soil sample for analysis. Sent the sample to a soil chemistry laboratory. This analysis will determine the soil amendments that can be incorporated before planting, as well as fertilizer nutrients that should be applied, and application rates. 3. Developing a soil conservation plan- construction of contour ridges, storm drains, planting of wind breaks as well as construction of access roads to allow vehicles to entre and traverse the field. 4. Primary tillage- ploughing should be done using ox- or tractor drawn ploughs like mouldboard ploughs or disc ploughs. The land should be initially cultivated using subsoilers. When the soil tilth is satisfactory you can now proceed to plant your crop. 5. Secondary tillage -rolling or discing the land, this will help break the soil cods and prepare a fine tilth as well as levelling the seed bed (if you are satisfied proceed to plant you crop) 6. Harrowing will help in levelling the seedbed and remove trash. After this operation land is ready for planting. Tillage - Refers to the planned disturbance of the soil. - Tillage refers to mechanical manipulations of the soil that provide necessary conditions favourable for the growth of crops. Primary tillage - - It is tillage which cuts, inverts and /or shatters the soil to a depth 15-36 cm. It may bury trash by the inversion and it usually leaves the surface rough. It is a more aggressive, relatively deeper operation and implements tend to be heavier and more strongly constructed than for secondary tillage. Examples of primary tillage implements: Mouldboard ploughs, chisel ploughs, Disc ploughs, Sub-soilers Discuss the advantages of primary tillage to a farmer. [5] Advantages of primary tillage:  loosening and aerating the soil surface layer;  used in hard soil;  for deep ploughing;  in virgin lands; removal of obstacles;  incorporation of organic matter;  improves seepage/ drainage/ aeration;  controls pests /disease  incorporating fertilizer  covering plant residue from previous crop or mixing the residue into the surface layer of the soil  mechanically destroys weeds  it helps water infiltration  it helps conserve soil moisture Disadvantages of primary tillage 57 GWANZURA.R. guide 2020-0773266377 / 0717 558 917        Dries the soil before seeding Soil loses a lot of nutrients Decreases the water infiltration rate of the soil and results in more runoff and erosion Results in dislodging of the soil particles thereby causing erosion Reduces organic matter content in the soil. Reduces activity of microbes, earth worms and ants Compaction of the soil also known as tillage pan. Secondary tillage - - It refers to tillage operations that follow primary tillage and are for the purpose of preparing a final seedbed suitable for planting, seed germination seedling establishment and weed control It works the soil to shallower depths -5-15 cm Secondary tillage operations are meant to improve the seedbed and increase soil pulverization. In the end this will leave the land as uniform as possible. This is accomplished by use of harrows, rollers. cultivators, blade harrows and pulverisers. Conservation / minimum tillage - It is any method of soil cultivation that leaves the previous year’s crop residues on the field before and after planting the next crop. - The method leaves at least 30% of the crop residues on the soil surface. - This improves water movement, which reduces the amount of soil erosion and run off. It is suitable for erosion prone areas. - Conservation tillage practise include no till, strip till, ridge till, and mulch till. - Each method requires different types of specialized or modified equipment and adapting in management. Benefits of conservation or minimum tillage Discuss the advantages of conservation tillage. [10]                 Promotes crumb structure of soil; Reduces leaching of nutrients Reduces erosion; Improves infiltration; Liming reduced; Reduces costs of fuel per given hectare of crop; Enables early planting of crops/fast Residues provide cover for microbial activities Organic matter left on top decays to form humus/ fertility. Labour costs reduced/ cheap Reduced fertiliser rates Maintains soil temperature Moisture conservation. Conserve energy due to fewer tractor trips across the field. Reduces potential air pollution from dust and diesel emission Reduces compaction that can interfere with plant growth. 58 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* Legume and cereal production      grow one cereal and one legume crop  Suitable cultivars from: - Cereals:-maize, sorghum, wheat - Legumes:-groundnuts, field beans, soya beans  Seed rates carry out management practices on selected crops describe harvesting of the crop store harvested crops market crops Cereal crop production (Maize production) The social and economic importance of maize - maize is the stable food crop in Zimbabwe - it can also be used as feed for livestock - it is also used in the brewery industry for brewing beer. - Used to produce cooking oil - It can be used in starch manufacturing. The soil requirements for maize - Deep fertile and well drained soils rich in organic matter. - Soils shoud be medium textured with good water holding capacity - Maize plants at early growth stage are highly susceptible to water logging so water should not be allowed to get stagnant in the field. - The ideal soil is one which is neither clayey or sandy. - Optimum soil pH range is 6.5-7.5 Climatic requirements for maize - Thrives in warm weather, were night temperature do not go below 15oC - Crop cannot withstand frost at any given growth stage - Young plants are highly susceptible to hail storm - Maize is generally grown where rainfall ranges between 400-900mm - Rainfall should be well distributed - Crop needs bright sunny days for accelerated photosynthetic activity and rapid growth of plants. - Prolonged cloudy period is harmful for the crop as it encourages then development of fungal diseases Factors considered when selecting suitable Maize variety. - Potential yield of the variety. - Standability- resistance to lodging as it reduces harvesting losses and damage. - Insect pest resistance - Drought tolerance - Number of days to reach maturity - End use value such as milling, stock feed and silage. 59 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Cob height- is related to maturity. Excessive height may contribute to plant lodging in mind and rain situations. Husk cover- they function to prevent damage caused by larvae, and protect the grain from weather. Common Maize varieties: - Very early maturity e.g. SC403 ▪ Very tolerant to maize streak virus and molfle viruses. ▪ A relatively short, flinty ear and excellent yields. ▪ Stability over a range of environments. ▪ Outstanding drought tolerant. ▪ High potential yields. ▪ Tolerant to diploid ear rot. - Early maturity- e.g. SC513 ▪ Average tolerance to both Maize streak xims (MSV) and grey leaf spot (GLS). ▪ Takes about 137 days tp mature. ▪ High yielding potential. ▪ White dent variety. - Medium maturity- e.g. SC602 ▪ Moderately susceptible to GLS and MSV. ▪ Takes about 144 days to mature. ▪ Yellow dent varieties. ▪ Has excellent yield potential. - Late maturity – e.g. SC709 ▪ Susceptible to MSV. ▪ Very tolerant to GLS. ▪ Takes 151 days to mature. ▪ Excellent yield potential. Timing of planting maize - October to December - Any delayed planting will result in corresponding decline in yields - Planting methods include water planting, dry planting and rain planting. Seed rate - On average , 25kg of certified seed is required per 1 ha. - However seed rate depends on seed size and the targeted population Fertilizer requirements - 300kg/ha of compound D or Z as basal dressing - Top dressing of Ammonium Nitrate at a rate of 250kg/ha - Top dressing can be applied as split.i.e the first application when crop is at knee height of 4 weeks from planting and then later applied at tasselling stage. Plant spacing - Short season cultivars; 900mm by 230mm - Long season cultivars: 900mm by 300 mm Plant population - It is correlated with more yields and should be based on soil type. 60 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - However soils have higher water and nutrient holding capacity than sand soils and have high yield potential. The plant population per hectare of a maize crop with a spacing of 90cm × 30cm can be calculated as follows : 𝐴𝑟𝑒𝑎 (𝑚²) 𝑖𝑛𝑟𝑜𝑤(𝑚)×𝑖𝑛𝑡𝑒𝑟−𝑟𝑜𝑤(𝑚) Plant population = 10 000𝑚2 0,3×0,9 𝑚 = = = 37 037,04 31 037 plants Problem 1. Calculate number of maize plants in one ha area if inter and intra spacing is 60cm and 20 cm, respectively. Given area (m2) Number of plants in a given area = ------------------------------------------________ Area required by single plant (m2) 1 ha = 10000 m2 Area required by single plant (m2) = inter spacing/100 x intra spacing/100 = 60/100 x 20/100 or 0.6x0.2 or 1.2 Number of plants/ha = 10000/1.2 = 8333.33 or 8333 Problem 2. Calculate number of wheat plants in 400m2 area if inter and intra spacing is 22cm and 10cm, respectively. Given area (m2) Number of plants in a given area = ------------------------------------------________ Area required by single plant (m2) Area required by single plant (m2) = inter spacing/100 x intra spacing/100 Area required by single plant (m2) = inter spacing/100 x intra spacing/100 Number of plants = 400/0.022 = 18181.81 or 18182 Calculation of seed rates Recommended quantity of crop seed (kg) per ha or square meters 61 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Seed required = (kg) ------------------------------------------------------------------------------- for the area Given area in ha or square meters Questions: 1. A silage maize crop is planted at a spacing of 800 mm X 200 mm, calculate the plant population per hectare. Show all working. [5] (N2013) Harvesting indices (signs of maturity) - Black layer at the top of mature kernel , - Grain moisture at onset of maturity occurs within the range of 25-350C, - Number of days to reach maturity of the variety being grown , - Drying of maize cobs , - Kernels become hard to bite and glossing in color, - Husks and leaves become brown and papery. Harvesting methods - Harvesting is the operations of gathering the useful part or parts of the plant. - It is a voluntary intervention by man, carried out at the time when all the nutrients have been developed and the edible parts have reached maturity. - Maize crops are first cut either as whole or partially (cobs) and then threshold and cleaned to separate the grain from the cobs and straw. - Two methods can be used : -  Hand harvesting  Cut the maize stalks with machetes or hoes and stack in the field for the cobs to dry.  Pluck maize cobs from the stalks and remove them from the husks.  Put cobs in bags or stationary cart to contain the cobs for later storage.  Transport for storage. Harvested by hand and cobs are stored in traditional structures (granaries). This method does require specific tools, it simply involves removing cobs from stalks.          Machine harvesting The mechanical harvester detaches the cob of the Maize from the stalks. Combine harvesters carry out several tasks in one operation. They remove cobs from stalks, dehusk, shell and pour grain in trailers or bags. A combine harvester is used. The combine harvester performs the gathering, snapping and removal of the trash. The rotating reel pushes or gathers the uncut stalks against the cutter-bar. Snapping is the breaking of the maize ears from the stalks. The crop is conveyed and fed into the machine. 62 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  The material is moved into the cylinder and concave for threshing. Thus the grain is removed from the ears.  Straw walkers separate the grain. Unshelled grain fall through the straw walker opening and returned for re-threshing.  The cleaning shoe (chaffer sieve and blowing fan) separate the kernels from impurities.  Describe the advantages and disadvantages of mechanical methods of harvesting crops. [5] Advantages  Less labour;  Stover chopped leaving land ready for ploughing;  Faster method. Disadvantages  Only upright stalks decobed;  Weeds may block combine harvester;  Requires even land;  Produces poor grade; Threshing methods - Traditionally maize shelling is done as manual operation , maize kernels are separated from the cobs by pressing on the grain with the thumbs. - Maize shellers, are hand operated machines. - Threshing maize cobs which have been placed into bags and the beaten using sticks. - Motonised threshing –small maize shellers, equipped with a rotating cylinder of the peg or bar type are available on the market. Harvesting stages for maize Field drying on stalks Harvesting / stocking Temporary storage Drying Dehusking GWANZURA.R. guide 2020-0773266377 / 0717 558 917 63 Shelling / cleaning Storage Marketing Maize storage - Maize for marketing should be stored shelled in a closed stored with the use of pesticides. The spread of the grain borer in the region makes the use of good storage essential. Delayed harvesting of maize lead to higher losses because of attacks by termites , rodents and domestic animals. Crops can be infected by pests. Storage facilities should serve the following purposes × provide protection –ground & water rain -insect pests -excessive heat. Maize storage facilities - Drying storage cribs – used normally when storing maize on the cobs, and can also be used to store shelled grain in bags. - Mud or cement – plastered buckets. - Brick bins - Ferro cement bins – Preparing Maize for marketing - GMB buys the maize soon after harvesting. - The farmer can find milling buyers at a Marketing Board or Co-operative Depot. - Maize is marketed through the GMB at a price gazette by the government. - Also due to trade liberalization, maize processing companies like millers and breweries provide an alternative for maize growths. - Farmers can market their grain through the open market like Mbare Musika at concessionary prices. 64 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Harvesting losses - Pre-harvest losses: Occurs before the crop is harvested due to over drying, weather, pests, and diseases. - Header losses: Losses are caused by the reel operation, e.g. lodging. - Threshing losses: Losses result from incomplete removal the seed from the seed head (under-threshing). - Separating losses: These are losses of threshed grain over straw walker. - Cleaning shoe losses: These are the losses of grain passing over the shoe. Expected yield • Depends on cultivar and rainfall distribution. It ranges from 012t/ha. Post-harvest technology: Drying maize - Drying is the systematic reduction of crop moisture down to safe levels for storage, usually 12%-15.5% moisture content. May be left to dry in the field for 4-7 weeks, either in stacks or heaps. Late harvesting can shorten drying duration. Wet grains and attract insects and mold. Drying the maize on the ground will make it absorb moisture and pick up dirt and insects. Shelled maize can be dried in layers on bare ground, mats or plastic sheets. Cob may be suspended from poles on free branches. Artificial driers and ventilated structures such as cribs, are modern methods. Proper drying results in increased storage life of the grains, prevention of deterioration in quality, reduction of biological respiration that leads to quality loss of grains, and optimum milling recovery. Shelling and winnowing - - Shelling is the process of separating the seeds or grains from the cobs. To maintain the high quality of the harvested grains, it should be shelled immediately after harvesting. Maize shelling is difficult at moisture levels above 25%. This may lead to mechanical damage to the grain. Shelling is commonly done by beating maize cobs with stick in a sack or a confined floor space or by use of powered sheller. Beating maize will result in physical damage which makes it more vulnerable to pests and moulds Cleaners or winnowers separate kernels from impurities. Milling 65 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Milling is the process wherein the maize grain is transformed into a form suitable for human consumption. Dehulling - Dehulling is the process of removing the pericarp or seed coat from the kernels. The methods include: • Hand pounding and • Use of mechanised dehullers. Storage - Store in bags, silos or granaries. Rooms must be moisture proof, dry and cool, tidy and clean. Store at 12-13% moisture content. Apply insecticides such as Malathion 1% dust. • Protect from vermin by putting rat baffles on granary pillars. Losses due to poor storage Mould - Microbial infection in storage occurs due to inadequate drying of produce. Fungal infection results into rots and development of aflatoxins, which are poisonous compounds to live stock and cause cancer in human. Losses due to mould  Loss of weight  Loss of quality (smell, taste, colour, nutritional value, germination) Spillage - Careless handling of either maize cobs or grains can lead to spillage. This leads to loss in terms of quantity. Spillage can also lead to loss of quality in case contaminated grains or cobs are again mixed with the clean stuff. Preparation for market - Shelling to remove the kernels or grain or pips. - Winnowing to remove chaff, weed seeds and small grains. - Grading according to quality or size. The term “quality” as applied to food material refers to those attributes of the food which make it agreeable to those who consume it. Attributes of quality involve colour, flavour, texture, nutritional value and the absence of harmful substances. - Weighing and packing in 50kg bags. 66 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Marketing through Grain Marketing Board or other merchants. Diseases, pests and weeds are common causes of crop damage. State and explain other causes of damage to crops. [10]              Field operations; example; Livestock/ wild animals eat all crops; High temperatures cause plants to wilt and die; Frost- air drop to freezing point and damage crop; Hail- water that has frozen in the atmosphere causes damage to leaves; Water logging- plants turn into yellow colour and may die; Soil capping; Soil pans Drought- plants wilt and die Nutrient deficiency- stunted growth; Fire –destroy all crops Wind – dislodge plants Floods legume crop-groundnuts - There are mainly seed crops that are used to produce oils and fats. Their main uses are given below.       Extraction of cooking oil. Manufactured margarine. Soap. manufacture groundnut cake. livestock hay. confectionary purposes e.g sweets. Varieties SHORT SEASON VARIETIES MEDIUM SEASON VARIETIES LONG SEASON VARIETIES Plover Falcon Valencia R1 Valencia R2 Natal common Shallow Flamingo Heron Egret Makhulu Red For a named legume crop, discuss the factors that affect the choice of a suitable variety to grow. [7]  rainfall required;  days to maturity;  yield per hectare;  disease and pest tolerance;  drought/ frost tolerance;  fertilizer requirements; 67 GWANZURA.R. guide 2020-0773266377 / 0717 558 917     easy use of machinery; growth habit; market demand; farmer’s preference/ taste. Soil requirements - Groundnuts grow well on fertile soils, well drained and deep soils. - e.g. sand loam, clay, loam soils. Climatic Requirements - Prefer warm temperature. - Rainfall required ranges between 725-865mm per annum. - Don’t tolerate frost. Land preparation - Land is ploughed, rolled, and disced to a time tilth. - Ridges are constructed on heavier soils for easy lifting during harvesting. For a named legume crop, describe its cultivation under the following headings: (i) Method of planting, [4] Planting time - Planting can be done by hand or using a machine planter; - Plant in rows; - Timing; November to December - Depth of planting 25- 80 mm; - Planting methods - Can be planted by either hands or groundnut planters. In rows - Spacing  row spacing 300- 450 mm;  in row spacing 50 – 100 mm; Fertilization of legume crops  Apply compound S after ploughing and harrow it in.  Top-dress when symptoms of deficiency have been shown. Apply gypsum for pod formation. Weed Control  Can be done by hand pulling, use of herbicides, mechanically or culturally. Harvesting  Done when groundnut plants are mature. Signs of Maturity Signs of maturity. [4] 1. Pods are firm / dry 2. Seed colour is true to type e.g. Makhulu red has red kernels. 3. Pods well filled; 4. Seeds/ kernels rattle inside pods; 68 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 5. 6. 7. 8. 9. Leaves start falling; 50- 60 % mature pods; Testa hard to peel off; Appearance of block markings on the inside of pods. Pods open easily, when rubbed and pressed between the fingers. Describe the harvesting and marketing of a named legume crop. [7] Harvesting Procedures  Ground nuts  Start to harvest at 50- 70 % kernel maturity;  At 90% defoliation of leaves;  Loosening of soil;  Lifting of crop; this is done by hand or using machine;  Leaving to dry for 2-3 days / curing;  Shelling;  Cleaning, grading and packing into 50kg bags and weighed before being sown with twine. Storage  Best stored in pod form to give protection against pest e.g. weevils in bags or silos. Marketing  Market at 10-12 % moisture content;  Pack into 50Kg bags;  Grade the crop before packing;  Market at GMB/ any buyer;  Weighing; branding; percing; transportation What precautionary measures can a farmer take to protect a named harvested legume crop from point of harvesting up to storage?  Groundnuts;  Harvest: soon as crop is ready; prevent insects damaging crop in field;  At correct moisture content; 12-14 %  Clear storage places/ granary; burn / bury old crop residue;  Clean grain/ winnowing;  Clean dirty sacks;  Fumigation; use insecticides; kill insects, use ash; bucketful on 70 kg grain; on use; wash ash away  Rodents; fix rat buffles to crib; block-up rat holes; broken glass/ cement; keep a cat; use poison;  Humidity; protect from rain/ moisture ; direct sun. November 1997 10). Describe the cultivation of a named legume crop under the following headings. a). Name of legume crop b). Preparation of soil for planting (5) c). Methods of planting (2) d). Signs which indicate that the crop is ready for harvesting. (3) Possible Answers 69 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 a). Name of legume - groundnuts b). preparation for planting - cheating / stumping burning and filling holes - ploughing / digging / sub soiling to a depth 230 – 300mm - discing / harrowing rolling and levelling - fertilisation, manuring and liming c). Methods of planting - by hand or machine planters - plant in rows of furrows spacing 600mm x 100mm - timing/ plant in summer – November to February - Depth – 25 to 75mm d). Signs which indicate that the crop is ready for harvesting - pods are dry, turn brown - when pods are well filled - brown leaves start failing - 50 to 60% pods are mature November 1998 10a). For a named legume crop, describe the operations that are carried out from harvesting to marketing. (6) b). Explain the difference between selective and non- selective herbicides. (4) Possible Answers a). For a named legume crop, describe the operations that are carried out from harvesting to marketing. name of legume: ground nuts Lifting / digging/ picking, hands / groundnut lifter Curing on racks / drying; 2 – 6 weeks of drying Plucking / threshing beans, groundnuts stores best in pods Winnowing Shelling Protect from pests Bagging Store in a dry place, moisture below 9% Grading Weighing / 80 kg Beans / 50kg Sold to Grain Marketing Board/ National Foods / Lever Brothers b). Explain the difference between selective and non-selective herbicides. Selective-Kill only the weeds, without harming he crop, kill weeds within a crop Non- selective - Kill everything i.e both crops and weeds, use for pathways / construction sites / parking sites ********************************************* 70 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 SUB TOPIC: CROP PROTECTION ********************************************* Pests  explain methods of pests control  describe the advantages and disadvantages of each method  describe mode of action of the main groups of pesticides Methods of pest control 1. Cultural methods Explain 5 cultural methods of controlling pests. [5] These are practices that break life cycles of pests when cultivating crops, for example, - - Crop rotation breaks pest life cycle and reduces their population, Planting resistant cultivars; Removal of weeds Use of catch crops Using ash; Planting certified seeds; Rogueing; Hand picking/ squashing pests; Weeding destroys pest habitat. Early planting allows pest to emerge when crop has fully established. Field hygiene such as burning or destruction of crop residues. Growing resistant/ tolerant varieties. Use of legislation that prevents introduction of new pests into the country. Hand collection and squashing under foot. Use of clean planting materials, such as seed, cuttings, buds and root stocks that are free from pests. Avoid high plant densities Physical barriers- floating row covers to the crop from pests. 2. Chemical method It involves use of poisons that are harmful to a particular pest. They ca be applied by dusting, spraying or fumigation of a crop. The mode of action of the main groups of pesticides Stomach poisons: -They kill when eaten by the target organism. Contact poisons: -They are absorbed through the skin or cuticle of the pest. Pest are killed when they are sprayed directly or get in contact with the sprayed foliage. Systemic pesticides: -These are absorbed into the plant and travel in sap or juice to other parts. They kill sucking pests when ingested, e.g. Dimethoate 40% E.C. Fumigants: - They act in gaseous form and interfere with respiration. They destroy the pest by suffocation, e.g. Ethyl bromide. 71 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - 3. Biological method This is the employment of any biological agent (natural enemies) for control of pests. It involves the use of beneficial organisms, such as insects or vectors that feed on pest. For example, Use of predators, e.g. Ladybird beetle. Introduction of fungi or virus that feed on pest. 4. Physical pest control. - It is a method of getting rid of insect and small rodents by removing crashing or setting barriers that will prevent further destruction of crops. Classification of Pests 1. Biting and chewing Pests - These are insects which feed by biting pieces of plant material and chewing. Very good examples of such pests are: locusts, crickets, caterpillars and beetles. Damage caused by biting and chewing pests Losses in plant yield can be brought about in different ways by biting and chewing pests as indicated below: - - During feeding some pests produce substances which irritate the host plant leading to proliferation and gall formation. Loss of photosynthesis tissue due to the eating away of the leaf lamina of the plant and leaf drop, e.g. by leaf worm There is destruction of seedlings and young plants, e.g. vegetable seedlings can be destroyed by cutworm. Feeding of pests from the growing points lead to the destruction of buds and shoots e.g. the bud worm in tobacco. Some pests feed by boring and tunneling the stems interfering with the movement of sap up and down the plant and weakening of the plant, e.g. maize stalk borer in maize. During feeding the pests destroy flowers, seed and fruits there by significantly reducing fruit production, e.g. cape mounted rifle beetle in sugar bean. Tubers and roots can be bored or eaten by pests in the soil leading to reduced yields, e.g. potato tuber moth in potatoes. 2. Piercing and sucking Pests - Pests in this category have part or all of the mouthparts modified into piercing proboscis. They suck sap from the xylem or phloem tissues of the plant. Examples of such pests are from the order Acarina, homoptera and thrips. Pests that are vectors of pathogens - These are insects that transmit diseases to plants making them important to agriculture. 72 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Examples are fruit fly which transmits tobacco and cotton leaf curl viruses, aphids transmits groundnut mosaic virus, and leaf hopper which transmits maize streak virus. It is important to note that very low populations of disease vectors can lead to serious crop damage. 3.Boring pests - These bore into plant parts and destroy the tissues of the plant or fruit or seeds. - They have sharp snouted mouth parts which tunnel into plant tissues. - Examples include: weevils, stalk borer and American bollworm. Describe 5 harmful effects of pests on crops. [5]  Destroy seeds;  Burrow into fruits/stem;  Cuts stems of plants causing lodging  Lower grades of crops;  Reduce yields;  Causes defoliation; ********************************************* Diseases  describe methods of disease control  identify the correct chemicals used to control crop diseases Importance of disease management - Reduces or excludes the initial inoculum. - Reduces crop losses. And hence yield increases - Improves quality of produce. Methods of disease management Cultural - Refers to those growing methods that reduce pathogen levels or reduce the rate of diseases development. These include:  Crop rotation. It helps keep populations of pathogens from building up to damaging numbers.  Sanitation. This involves ploughing under, removing and properly disposing of infected leaves, washing hands and burning of crop residues.  Host eradication: It refers to the removal of undesirable plants that might serve as a host reservoir for diseases that attack cultivated crops.  Use of optimum plant populations.  Applying adequate fertilisers and use of vigorous growing crops.  Practicing intercropping and early planting. Chemical - Pesticide application method works by eliminating disease-causing organisms. Biological 73 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - Crop rotation may be an effective means to prevent a parasitic population from becoming well-established, as an organism affecting leaves would be starved when the leafy crop is replaced by a tuberous type. Disadvantages of biological methods of disease management. ▪ Need careful study before implementation. ▪ It is slow to work/ineffective. ▪ Predator may fail to establish. ▪ Predator may be difficult to get. ▪ Lack of knowledge. Legislative Avoid the introduction of harmful non-native organisms by controlling all human traffic and activity. Integrated Disease Management (IPM) This involves use of two or more of these methods in combination offers a higher chance of effectiveness. ********************************************* Weeds     describe methods of weed control differentiate herbicides as selective and non-selective differentiate herbicides on the basis of timing of application compare effectiveness of different weed control methods Methods of weed control Describe other methods of weed control besides use of herbicides. [5] 1. Cultural method - Cultural weed management is defined as any practice or effort adopted by the farmer in crop production which minimizes weed interference problem . Cultural weed methods include:  Hand weeding.  Mulching smother weeds by excluding light from them.  Crop Rotation.  Tillage.  Burning crop residues destroy weed seeds in the process.  Flooding.  Sowing/planting time and crop spatial management. 74 GWANZURA.R. guide 2020-0773266377 / 0717 558 917     Crop genotype choice. Cover crop (used as Living mulches). Intercropping maize with cowpeas reduces Striga aciatica Fertilization. 2. Mechanical method - Animal or tractor drawn machinery, including hand hoe is used to control weeds. The implements are used after the crop has emerged. 3. Biological method - - - Biological weed management refers to the use of biological agent – pest, predators, pathogen and parasites to control weeds. It involves the control or suppression of weeds through the action of one or more organisms by natural means, or by manipulation of the weeds, organism or environment. Discuss the biological methods of controlling weeds. [5]  Use of living organisms to control weeds;  Living organisms should not prey on wanted crops;  Living organisms should multiply rapidly;  The weed should be palatable;  By pass of threshold; It involves:  Control of weeds with vertebrates and invertebrates (Macrobial weed control).  Use of micro-organisms such as plant pathogen (microbial weed control).  Live mulch: Live mulch is the crop production system in which a food crop in planted directly in the living cover of an established cover without destruction of the fallow (cover crop vegetation).  Perennial legumes such as Psophocarpus palustris, have been evaluated and found suitable as live mulch. Reasons why biological methods of weed control are not widely used by farmers - predators may not be available. - needs time to study the pest natural enemy relationships. - new predator-crop relationships. - natural enemy takes time to establish. - natural enemy may not establish/adapt to new climate. - take time to multiply to effective levels of populations. - it is a slow method. - ineffective method. - plant natural enemies may compete for nutrients. -lack of knowledge. 4. Chemical method 75 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Chemicals that are used for killing weeds or suppress the plant growth are called herbicides. The practice of killing the undesirable vegetation (that is weeds) with herbicide is called chemical weed control. Type of plants killed (Selectivity). Herbicides can be divided into two groups depending on their selectivity. - Selective herbicides, kill specific targets they come in contact with, while leaving the desired crop relatively unharmed. Non-selective herbicides, kill any plants they come in contact with. They may be translocated. Time of application (When applied). - There are three groups:  Pre-plant incorporated herbicides: These are applied before planting.  Pre-emergence herbicides: They are herbicides applied before emergence of both the weed and the crop.  Post emergence herbicides: They are applied either when both the crop and the weed has emerged. Discuss the advantages and disadvantages of using herbicides in crop production. [10] Advantages of using herbicides - Faster/ covers a large area in short time; - Reduces labour costs; - Do not disturb root system; - Control weed seeds before they germinate - Used in wet conditions/ Can be used without loss of efficacy under wet conditions. - Can suppress weed germination. - More effective than other methods of weed control when properly used. - Faster than manual and cultural weed control. - Less likely to be adversely affected by erratic weather condition. - Pre-emergence application of herbicides protects crops from the adverse effects of early weed competition. - Effective /More effective against perennial weeds. Disadvantages - Not user friendly/ poisonous; Pollute the environment; Need skilled person/ knowledge; Some have long residual effect; Expensive; Need sophisticated equipment; Herbicides may be ineffective due to soil conditions. Weeds become resistant due to prolonged and constant use of a given herbicide. 76 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Crop injury as a result of poor sprayer calibration or wrong dosage calculation, faulty equipment or failure to follow label directions There could be side effect on the applicator. Adsorption by soil colloids. Has residual effect on subsequent crops. Can be lost through volatilization. Proper calibration is needed. Can damage crops if over used. ********************************************* Agrochemicals     explain the precautionary measures taken when using and storing chemicals describe the toxicity levels of agro-chemicals calculate the mixing ratios of chemicals used in spraying draw and label parts of a knapsack sprayer Ways of applying pesticides - These include:  Spraying  Dusting  Fumigation  Baiting  Seed dressing Safety precautions when using farm chemicals Explain the safety precautions to be followed when using pesticides. [5]            Read instructions on label; Don not blow nozzles with mouth; Wear protective clothing; Keep out of reach of children; Wash body after using; Keep chemicals in their storage containers; Do not eat when using chemicals; Do not smoke when using chemicals; Spray while on the windward side; Avoid cleaning the equipment in water sources meant for other use/ avoid water body contamination; Proper disposal of empty containers; Pesticide toxicity - Manufacturers’ chemicals are labelled with triangles of different colours. - The colours indicate the toxicity of each chemical. 1. Green triangle  Contain the least poisoning pesticide or chemical. 77 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 2. Amber-Triangle  Chemical contained is poisonous. Handle with care 3. Red Triangle  Chemical contained is very poisonous. Handle with care. 4. Purple- Triangle  Chemical contained is extremely dangerous. Handle with extreme care. ******************************************** TOPIC 4: ANIMAL HUSBANDRY ********************************************* SUB TOPIC: ANATOMY AND PHYSIOLOGY ********************************************* Digestive system of a ruminant and non-ruminant  identify parts of the digestive system of a ruminant and non-ruminant  explain functions of parts of the digestive systems  distinguish the difference between digestive systems of a ruminant and nonruminant Ruminants - Animals which have four stomach chambers and chew the cud - e.g cattle, sheep and goat. Non-Ruminants - Animals with a single chamber and they do not chew the cud - E.g horses; donkeys; pig and rabbits Digestive system of a ruminant (cattle) 78 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 1) 2) 3) 4) 5) Oesophagus Rumen Reticulum Omasum Abomasum Functions of the parts Gullet (oesophagus)- connects the mouth to the rumen Rumen- stores food, contains micro-flora bacteria which break down cellulose; a site for synthesis of vitamin B complex. Reticulum- separates coarse and fine materials. Omasum- assists in water absorption Duodenum- protein, fat and starch digestion. Ileum- absorption of food into the blood stream. Colom- water absorption. Rectum- stores food for a time before it is passed out as waste. Digestive system of a non-ruminant (pig) Diagram Functions of the parts Part Mouth Oesophagus Functions Mystification of food (chewing) Mixing food with saliva Chemical digestion of starch by enzymes salivary amylase. Muscle-less tube that connect the mouth to the stomach. Food passes through oesophagus by a process called peristalsis. 79 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 stomach duodenum Pancreas and pancreas duct liver Gall bladder Bile duct Small intestines/ileum Large intestines/colon Caecum Rectum anus - - Chemical digestion of food as stomach walls breaks down food into smaller molecules. Chemical digestion by enzymes also take place. Proteins are digested by the enzyme pepsin. Pepsin works under acidic conditions. Food from the stomach moves to the duodenum for further chemical digestion. Enzymes from the pancreas digest carbohydrates, fats and proteins. Fats are digested by pancreatic lipase to fatty acids and glycerol. Proteins are digested by pepsin to peptides. Starch is digested by pancreatic lipase to maltose. Enzymes in the duodenum will be in the pancreatic juice from the pancreas. Secrets pancreatic juice containing enzymes. The pancreatic duct connects the pancreas to the duodenum. Produces a bile needed for emulsification of fats into droplets. Stores bile produced in the liver. Connect gall bladder to the duodenum The inner walls are made up of finger like projections called villi. Villi absorbs nutrients into the blood streams. Chemical digestion also takes place. Absorption of water and mineral salts Bacteria in the caecum digest cellulose using enzymes cellulose. It is small in non-grazers but large in grazers like donkeys, horses and rabbits. Stores dung or faeces before they are passed out. Passage for dung/ faeces. There are 2 types of digestion that take place in non-ruminants: 1) Mechanical digestion This is the physical digestion that occurs through the chewing of food and muscular contraction in the stomach. 2) Chemical digestion This is the digestion that takes place throughout the digestive system by enzymes: maltase, lactose, peptidase. Enzymes are biological chemicals that acts as catalysts that speed bio-chemical reactions. Enzymes breakdown food particles into small soluble that can be absorbed by the body. Digestive system of hen Diagram 80 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Functions of the parts Part Crop Proventriculus (upper stomach) Gizzard (lower stomach) Liver Gall bladder Small intestines Short length of colon caecum cloaca Functions Storage of food after swallowing. Softening of food by secretions from the crop walls Contains enzymes which digest food Has thick walls and small sharp stones for grinding the food Produces bile Stores bile Absorption of nutrients into the blood streams Chemical digestion Absorption of water and mineral salts Has two for breakdown of cellulose. Passes out droppings. Characteristics of ruminants and non-ruminants Ruminants Four chambered stomach Chew the cud Digest cellulose in the rumen Microbial digestion Synthesis of vitamin B complex and vitamin k No ptyalin in saliva Non ruminants One chambered stomach Digest food ones/ do not chew the cud Digest cellulose in the caecum No microbial digestion No synthesis of vitamin B complex and vitamin k Ptyalin is found in saliva November 1995 3.Fig 2 shows part of the digestive system of a ruminant a). Name the part labeled X in the diagram. (1) b). Show by arrows, in the diagram, the direction of food movement. (5) 81 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Possible Answers Fig 2 shows part of the digestive system in a ruminant a). name the part labeled X answer: Rumen b). Show by arrows the direction of food movement. Answer: the food moves as follows. ************************************************************************************************ November 1996 3. Study the diagram of the digestive system of a ruminant below and answer the question that follow a). b). c). Name these parts: A, B, C (3) Where is cellulose digested? What is the function of roughage in the diet? (1) 82 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Possible Answers a). Study the diagram of the digestive system of a ruminant below and answer the questions that follow Where is cellulose digested? - Rumen, reticulum and omasum What is the function of roughage in the diet? - prevent constipation - maintains peristaltic movements - source of energy - provide bulk in food ************************************************************************************************ November 1997 Name the organs where the following processes occur in ruminants Process organ 1 cellulose digestion rumen 2. ovulation ovary 3. sperm production testis 4. fertilisation oviduct 5. implantation of fertilized egg uterus ********************************************* Reproductive system of a ruminant    identify the parts of the reproductive systems of the male and female ruminant explain functions of parts of the reproductive systems draw and label the reproductive parts of male and female ruminant Reproductive system of a ruminant (bull) 83 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Seminal Ve sicle Bladder Prostate gland Vas Deferens Urethra Penis Functions of the parts Part Penis Testis/Testicles Scrotum Epididymis Urethra Seminal vesicle Prostate gland Cowpers gland Vas deferens Function Male reproductive organ used for copulation and urination. They store sperms, manufacture sperms. Produce testosterone hormone. They cover the testicles and control body temperature Store sperms until they mature Passage of sperms from the testicles Passage of sperms outside the urethra They secrete a fluid called semen which dilutes the sperm Provide nutrition for sperms and give them energy for movement Provide nutrition for sperm Transport sperms to the seminal vascules and penis Reproductive system of a cock diagram 84 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Part Function Testicle Produces sperms and testerone Sperm duct Transport sperms from the testicle Vas deferens Transport sperms to the seminal vesicle The female ruminant reproductive system (cow) Part Function Fallopian tube (A) This provide a passage for eggs from the ovary to the uterus. They are also the site for fertilization. helps in movement of egg to the uterus; Uterus The foetus formed in the fallopian tube implanted into the uterus. The uterus also performs such functions as protection. Site for implantation. Ovaries (B) They produce ovums at monthly intervals. They secrete oesterogen and progesterone. Cervix It separates the vagina from the uterus and protects uterus from bacteria Vagina (D) This is female organ for copulation. Acts as a birth canal 85 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Vulva The outside part which protects the vagina The reproductive part of a hen Diagram Part Function Ovary Development of ova (yoke nucleus) Feeding of ova until mature --when each ovule breaks skin and is released into funnel(infundibulum) Funnel Transit of ovum toward magnum (about 15minutes) Possible fertilization (male sperms hosted for up to 21 hours. Magnum Secretion of albumen and wrapping it around ovum (about 3 hours) Isthmus Construction of cell membrane (about 25 minutes) Transit of ovum with yolk and albumen to isthmus. Shell gland Coating of albumen with soft shell (about 20 hours) and moving it into vagina. Vagina Hosting egg for a few seconds before pushing it out through cloaca. Shell hardens immediately when exposed to air. Describe any three signs of heat in a female animal. [3]       swollen vulva; reduced milk yield; moist vulva; restless, reddish pink vulva; female mounts males/ females; female stands when being mounted; 86 GWANZURA.R. guide 2020-0773266377 / 0717 558 917   frequent urinations; high body temperature; ********************************************* SUB TOPIC: ANIMAL NUTRITION ********************************************* Types of feeds  classify feed stuffs Roughages Concentrates  identify feed stuffs for each class of livestock Classification of feed stuffs diagram (today page 117) Concentrates are feeds which per unit mass have a small volume but are concentrates and contain high percentage of digestive nutrients. Roughage is feed which its per unit mass contains a large volume and a small percentage of digestive nutrients. Animal feeds Forages and roughages 1. Pastures {legumes 2. Hay 3. Silage 4. Straw and hulls Lucerne, round nuts, cow peas} Forages and roughages  These are vegetable material in a fresh, dried or ensured state.  It consists about 56% of all the feeds fed its livestock  The feeds are usually low in digestive energy but high in content  Examples of roughages are grasses, hays, silage and legumes.  Roughages are lower in digestibility due to high lignin contents. Pasture  Pasture grasses and legumes both nature and cultivated are the most important single source of feed for ruminants such as cattle, horses, sheep and goat Legumes in pastures: Clovers, trefoils and Lucerne. They are good grazing plants with a high protein content. Grass pastures: Timothy and Sudan grass Hay   Standing hay: an area of grass can be left imgrazed towards the end of the wet season. In the dry season, the grass will still be there as dry as standing hay. 87 GWANZURA.R. guide 2020-0773266377 / 0717 558 917    Grass is most nutritious when it is young. If the grass is out and dried in the sun to less than 18%, in order to prevent molding, heating and spoilage during storage. Stored hay is fed to animals when sufficient fresh pasture grass is not available. Silage  This is a grass preserved without drying it. The grass is out whilst still young and put in large trenches or air tight storage container.  The grass begins to ferment due to bacterial action and heat.  Fluoric and lactic acid, which preserve the most feeds.  Moisture should be between 50-70%.  Low moisture may result in molding and spoilage  The high moisture results in the production of excessively acidic, unpalatable silage.  Corns, sorghum, grasses and leguminous forages are used in making silage. Protein concentrates 1. Sorghum and ground nuts 2. Peas and sunflower 3. Soya bean meal and cotton seed cake 4. Fish meal and blood meal 5. Feather meal 6. Meat meal 7. Lucerne meal ********************************************* Maintenance and production rations  calculate maintenance and production rations  prepare rations for both ruminants and non-ruminants Calculating production ration using Pearson Square method Mixing rations to produce a balanced diet Ration - A ration is a measured amount of food given to an animal per day. Maintenance ration - This is food given to the animal so as to maintain body weight. - The animal does not gain weight or lose weight. - To stay alife; - The ration is based on the weight of the animal. - A ration is given to animals to keep them alive, without gain or loss of body substance Production ration - Extra food above the maintenance; 88 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - This is extra feed given to the animal for it to gain weight, produce eggs, milk or feed young ones. Related to the amount animal is producing; This is a ration which is supplied over and above the maintenance ration to enable the animal to produce energy or products such as meat, milk, eggs , wool. It is an addition to maintenance ration. Simple ration formulation: Pearson`s square - Pearson`s square is a simple square way to calculate the amounts of feed necessary to meet a nutrient requirement of livestock and other animal. - This method is most effective when only two feed are being. - For example, Example 1. Calculate the mixing ratio of a feed stuff with 10% digestible crude protein (CP) if groundnut cake has 40% DCP and maize 8 % DCP. 40% (10-8)=2 Ground cake 10 maize 8% (40-10)=30 2 : 30 1 : 15 Groundnut cake : Maize Example 2. Prepare a feed formulation of 18 % digestible protein (DP) using soya bean cake of 32% protein concentrate and crushes maize with 6% digestible protein (DP). Example 3. You want to prepare a ration for layers with 18% crude protein using layers concentrate with 34% CP and maize with 7% CP. By using the Pearson’s square method, calculate the mixing ratios to come up with the correct feed. Example 4. (Nov 2015) A poultry farmer would like to formulate a ration with a total mixture of 500 kg, with a mixing ratio of 2 parts concentrate, to 3 parts maize meal. Calculate the quantities of each ingredient (show all working) Example 5. (Nov 2013) Illustrate the mixing ratio of a feed with 10% digestible crude protein (DCP) . if sunflower has 35% DCP and maize has 7% DCP. Use a Peason square method Factors that affect the intake of food by a farm animal 1. Palatability of food; 2. Body weight; 3. Type and level of production; 4. Ambient temperature; 5. High temperature depress appetite/ low temperature results in more feed intake; 6. Individual differences; 7. Amount of salt in food; 8. Texture of the food; 9. Colour of food; 89 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 10. Taste of food; 11. Nutritional status/ level of food; November 1995 3a). Write short notes on i). maintenance ration ii). production ration (4) b). Describe the importance of roughage, fats and a named vitamin in animal feeding. (6) Possible Answers a). Write short notes on i). Maintenance ration - amount of food fed to an animal - so that it does not lose or gain mass - to maintain body temperature - supply energy for breathing and blood circulation - repair worn out and damaged tissue ii). Production ration - feeding livestock maintenance  to produce milk, eggs, young, work and growth b). Describe the importance of roughage, fats and a named vitamin in animals Roughage - aids digestion - provides Volatile Fatty Acids - maintain normal ruminal activity Fats - energy production and storage - protection of vital organs - regulation of body heat ********************************************* SUB TOPIC: SMALL LIVESTOCK PRODUCTION ********************************************* Rearing of either rabbits or layers or indigenous chickens      identify breeds of a named animal choose a suitable housing site for a named animal design and construct housing for a named animal describe nutritional requirements of a named animal manage the young one of a named animal Rabbit production (rabbitry) Economic importance of rabbits  provide food i.e meat  a source of foreign currency.  Create employment  Can be used for ornamental purposes  Their fur and pelts can be used to produce toys, cushions and clothes 90 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  Provide manure Breeds of rabbits  Chinchilla Giganta  Flemish Giant  Californian rabbit  New Zealand white Suitable house for a rabbitry A suitable site should be:  Be able to protect rabbits from excessive heat (above 21oC)  Be well lighted and ventilated  Offer protection from rain, wind, pests and predators  Able to allow feeding and water conveniently. Features of a rabbit house  Should be large enough to allow feeding and watering conveniently and movement of rabbits  A rabbit house or cage should be raised enough to prevent attack by dogs and other predators  The roof should control entry of rain from all angles.  The floor should not trap droppings. Nutritional requirements for rabbits  Rabbits must be given a balanced diet. Containing all food nutrients i.e protein, carbohydrates, fats, water, vitamins, and minerals.  Pregnant does should be fed with good quality concentrate containing 20% protein and fibre.  Usually rabbits are fed with a) Commercially prepared pellets, and b) greens and hay Mating  When mating you take the doe to the buck;  When a buck and doe meet mating will take place almost immediately and will complete in one or two minutes;  Female rabbits do not go on heat and so mating can take place any time (even during pregnancy)  Females rabbits go on heat when introduced to the bucks. Testing for pregnancy in rabbits  This is done mainly by palpation after about 21 days from the day of mating. Preparation of nests for kindling  Nest boxes- this is where the doe kindles and they provide seclusion and comfort for the doe and the young ones.  They are made from either wood or metal.  The floor can be solid wood or wire netting. Management of doe and litter  Both the doe and the litter must be provided with clean and fresh water 91 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  They should also be provided with clean and fresh feed. Weaning  Is the removal of the young one from their mother or change from a liquid diet to a solid diet  Weaning takes place at 6 weeks of age. Sighs of ill health in rabbits  Watery droppings  Blood stained droppings  Poor appetite  Dull eyes  Wet nose  Passive stature  Restlessness  Ruffled fur Management practises of rabbits Nail clipping  Nail clipping controls fighting  It also controls damage to skin during scratching. ********************************************* Slaughtering, processing and marketing  slaughter and dress rabbits or off-layers or indigenous chickens  prepare pelts or eggs for market  compile financial and production records Slaughtering and dressing rabbits  Rabbits are slaughtered when they are 2.5 Kgs in weight.  Before slaughtering they must be kept without food for 12 hours but will be provided with plenty fresh water;  When killing the rabbit, place it on a table while holding the ears forward with the same hand  With the use of a club give a sharp blow behind the head.  Then tie carcass with the head down on the beam- remove the pelt (fur) between the hind legs and front legs all around to the bone.  Then make a cut through the pelt  After that start peeling off the pelt from the hind legs using the back of the knife to avoid cutting into the pelt.  Then after reaching the vent remove the fur using hands pulling gently downwards  Then open the stomach avoiding the bladder and intestines and then take the heart, lung and trachea (wind pipe)  Avoid opening the gall bladder because it may spoil the meat. Briefly describe the steps taken when slaughtering a rabbit . 92 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Preparation of pelts for market  Soaking in clean water for at least three days to soften them  Skin laid flat  Scrap off excess fat  Remove any stains, use benzene  Drying/ tanning Financial records  Costs of all inputs  Sales  Profit and loss Physical records  Mating records  Litter sizes  Dates of mating  Weight gains  Weaning weights  Amount of feed  Weaning dates ********************************************* SUB TOPIC: NON-RUMINANTS ********************************************* Rearing of Non-ruminants: Pigs or donkeys  identify the breeds of a named animal  describe housing systems  manage the named animal to maturity Management of Piglets up to weaning: Discuss a named non- ruminant animal under: (a)management from birth to weaning. [10] - dip navel of each piglet into iodine solution on day of birth; - cut umbilical cord to a length of 3cm; - cut teeth to avoid injuries; - put bedding to provide warmth; - castrate at 1 to 3 weeks; - vaccinations - provide iron - use a creep arc to separate sow from piglets - provide fresh water always - dipping /spraying / washing - dosing 93 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - give creep feed at 1 week of age; change bedding always; weighing identification, ear notching/ tagging/ tattooing. (b)types of records kept for the named animal. Mortality record/ health records Growth records: Food records: Breeding records: Financial records: Birth records: [5] show number of death and causes of death; weights of animals at intervals, number weaned; Date weaned type and quantity of feeds given; mating records; date of mating/breeds used; cost of feeding and sales numbers born Discuss feed stuffs grown on the farm which meet the nutritional requirements of a named non- ruminant animal. [9] Pig - green grass; provides minerals, proteins, carbohydrates; - legumes; proteins; minerals; vitamins - oils, for fats - water, solvent; - concentrates; proteins, carbohydrates - cereals ground; carbohydrates; ********************************************* Management of cattle or sheep or goats  list exotic and indigenous breeds in Zimbabwe  describe characteristics of exotic and indigenous breeds  describe management practices discuss the advantages and disadvantges of rearing each of the following breeds of cattle: i. exotic advantages  faster growth rate;  early maturity;  quick financial returns;  high meat/ wool/ milk yields/ carcass weight; disadvantages  susceptible to tropical diseases;  less tolerant to tropical heat;  expensive to buy;  high maintenance costs;  poor mothering abilities. ii. indigenous advantages  can survive under hash conditions; 94 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  resistant / tolerant to tropical diseases;  heat tolerant;  cheaper to feed;  good mothering abilities;  able to walk long distances in search of water after work disadvantages  lower growth rate;  slow maturity;  low financial returns  low productivity; describe the management of a named ruminant animal from birth to weaning. [9] cattle                provide warmth; naval dipping; provision of colostrum- provides antibodies; calf starter meals/hay for good growth; creep feeding; dosing to control internal parasites; weighing to assess growth rate; provision of clean water/ feeds hygiene identification/ ear notching; branding/ ear tagging/ tattooing dipping; plunge dip / spay race/ hand treatment; vaccination; prevent diseases by providing immunity; Castration, burdizzo/ knife, O rings; dehorning; dehorning iron / caustic soda/ knife record keeping; physical / financial record; for a named ruminant, describe its management from weaning to marketing. [10] cattle  weighing scale;  identification/ ear notching; branding/ ear tagging/ tattooing  dehorning; dehorning iron / caustic soda/ knife.  Castration, burdizzo/ knife, O rings;  Feeding, concentrate/ roughage;  Dosing, dozing gun;  Dipping; plunge dip / spay race/ hand treatment;  Record keeping; physical / financial record;  Hoof trimming / brushing. discuss why a farmer would prefer a spray race over a plunge dip. [8] - fast - less dip solution per animal - less wastage - less labour to operate; - fewer injuries to animals; - can dip young animals; 95 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - less initial capital; low maintenance; explain why it is necessary to supplement feed to ruminants in winter.  veld have low DCP;  increase protein content;  avoid mineral deficiencies;  for maintenance;  increase growth rate / milk yield;  high birth weight [5] ********************************************* SUB TOPIC: ANIMAL HEALTH ********************************************* Notifiable livestock diseases  recognise signs and symptoms of notifiable diseases  Discussing one disease from the following groups: a) Bacterial diseases: - anthrax b) Viral diseases: - foot and mouth or new castle c) Protozoan diseases: - trypanosomiasis  describe the control methods for notifiable diseases Health refers to a condition when all body parts of animals are functioning properly. Unhealthy refers to any deviation from normal health Causes of diseases Malnutrition Poison Physical injury Pathogens (disease causing organism) Sighs of health and ill- health Sighs of healthy animals Correct body temperature A good appetite Eyes clear and bright Dung of the right consistency Proper breathing Shiny coat Nose cold and wet Sighs of unhealthy animals High or low body temperature Poor appetite Dull eyes Watery dung or hard dung Irregular breathing Ruffled feathers and poor skin Nose warm and dry Disease causing organisms Bacteria Fungi 96 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Virus Protozoa Notifiable disease is a highly infectious disease which when detected should be reported to the nearest veterinary offices or police. Examples: anthrax, new castle and foot and mouth. Anthrax (a) with reference to a named ruminant animal, describe a named bacterial disease under the following headings: (i) cause, [1] (j) control and prevention. [6] Pathogen: - a bacterium called (Bacillus anthracis) Hosts: - cattle, sheep and goats Symptoms: Describe the signs and symptoms of a named bacterial disease of a ruminant animal. [5] - high body temperature/ trembling; - sudden death; - diarrhoea; - blood exudes from orifices of carcasses; - rapid decomposition of a carcass; - no stiffness of joints; - blood does not clot. Prevention and control - vaccinate annually; - with a live anthrax vaccine; - safe disposal of carcass/ burying/ burning; - report to veterinary department/ police/ councillor/ chief; - do not open animals believed to have died of anthrax; - do not eat meat from animals that died suddenly. Foot and mouth (FMD) Describe a named viral disease under the following sub-headings (i) symptoms; (j) prevention and control [4] [2] Pathogen: - caused by virus Hosts: - cattle, sheep, goats, buffalo, antelopes are carriers Symptoms: - Blisters on mouth, feet, scrotum, teats and udders - Continuous salivation - Lameness / difficult to move; 97 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Hooves drop/ coronate Control - Vaccinate with FMD vaccine - Quarantine/ isolate all suspected animals; - Slaughter affected animals; - Burn carcasses completely - Control livestock movement/ fencing - Creation of red zones in the event of an outbreak - Disinfect vehicles coming from areas of outbreak - Proper disposal of carcass - Report to authorities. Treatment: - There is no treatment. November 1997 For a named viral disease, describe the disease under the headings Name of disease – foot and mouth disease (F.M.D) a). Cause Virus b). Transmission contact with infected materials, food and saliva c). Symptoms - blisters on hooves and mouth - there is excessive salivation - hooves later break away from coronet - animals find it difficult to move d). prevention - vaccinate cattle - quarantine affected animals - destroy affected stock - notify the veterinary office, agritex or police. Treatment nil Trypanosomiasis or Nagana Discuss a named Protozoan disease under the following headings: (i) name of disease, [1] (ii) symptoms, [4] (iii)prevention and treatment, [6] Pathogen: - caused by a protozoan Host; - cattle Symptoms: - dull; rough coat; - watery eyes; - loss of weight; - high body temperature/ fever; - paralysis in hind quarters; - enlarged lymph nods; - loss of appetite; 98 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Prevention; - control/ spray tsetse flies; - interrupt life cycle of protozoa; - proper rest; - proper nutrition; - dose/ inject the animal using; - diminazine / homidium/ suramin; - use of traps; - male sterilisation; Treatment: - treat with berenil and antyrcide. The control methods for notifiable diseases cleaning – helps to remove dirt which invites flies and other insects which spread diseases. Disinfection- helps to kill pathogens (disease causing organisms). Ventilation – helps to throw away odours which invites vectors and insects like flies.  Ventilation also provides clean air to animals thereby preventing stress which causes diseases  Clean water and food  Help to make sure that all water and feed does not contain foreign items which may cause disease to livestock. Methods of controlling and preventing diseases - Natural immunisations- this is when an animal can resist diseases without being vaccinated. - Artificial immunisation – this is when animal resists diseases after regular vaccination - Provide a balanced diet - Maintain hygiene conditions - Destroy noxious plants e.g lantana Discuss the measures taken by government to prevent the outbreak of notifiable diseases. [10] ─ ─ ─ ─ ─ ─ ─ ─ ─ Quarantine: - prevent movement of animals from enclosed area to new area; Vaccination: -provide immunity against diseases; Notifiable disease: - need to be reported to authority, e.g foot and mouth. Importation of livestock/ products: have veterinary certificate/ inspection. Dipping: frequency once per week in summer; once per fortnight in winter; Permits/ movement control: -prevents movement from one area to the other. Awareness: - use of media to alert the nation; Fencing: - to prevent contamination with wild animals; Proper disposal of carcasses: - to prevent spread. ********************************************* 99 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Animal parasites and immunisation     Identify internal and external parasites of livestock describe the life cycles of one internal and one external parasite prevent and control parasites describe the types of immunity in livestock Parasites: - Life cycle - Symptoms - Prevention - Treatment - Control The Animal Health Act Immunity Parasites - Is an organism which feeds on host and cause harmful effects. - Explain the importance of studying the life cycle of animal parasites.  To know the destructive stage;  To understand the best stage of control;  To know the best time to control/ dose/ spray; - Parasites are divided into external internal parasites. External parasites - These attack the animal from the outside - E.g ticks, tsetse flies e.t.c One host tick Describe the life-cycle of one host tick. [5] - All stages are spent on the same animal/host Only one host is involved. Mating; the adult female tick engorges and drop off; Lay eggs; hatch into larvae; Look for host/ climb; moults into nymphs Moults into adult; Diagram Two- host tick Describe the symptoms of attack by a two-host tick for a named ruminant. [7] - Lumps on the skin; irritation/ itching; Wounds; restlessness; Wrinkling of the skin; Emaciation of animal; Anaemic; Loss of hair on the skin; Death. 100 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Describe the life cycle of a two (2) host tick. [7] Hosts 1:  Larva feeds on first host;  Moults into nymphs;  Nymphs feed on blood;  Fully fed nymph drops;  nymph moults into adult; host 2:  Adults attaches 2nd host and feeds on second host,  mating  fully fed female drops from host to ground;  Eggs laid by female on ground;  eggs hatch to larvae;  larva seeks host Diagram Prevention and control - Regular dipping and spraying with acaricides - Hand dressing; - Rotational grazing; - Burning grass; - Spraying pastures; State any 3 effects of ticks on farm animals. - Cause irritation - Suck blood/ anaemia - Cause disease/ red water/ heart water; - Reduces hides quality; causes wounds - Reduces meat quality; - Reduces growth - Loss of body weight/ emaciation; - Reduces production; Internal parasites (endo-parasites) - Are pests which live inside the animal’s (host) body from where they drive their nourishment and shelter. These affect animals from within Affect the liver and digestive system (stomach and intestines). E.g round worms; tapeworms and liver fluke. For a named internal parasite, discuss it under the following: (i)signs and symptoms, [8] Tape worms: Taenia solium - Dull/ rough coat; - Suffers from anaemia; - Retarded growth; - Lean/ loss of condition/ emaciation. 101 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Diarrhoea/ constipation; - Cooked rice grains in feaces resembling segments; - Calves look dull and pot belled; - Paralysis; - Abnormal appetite/ loss of appetite - Reduced production (ii)prevention and control. - Avoid grazing in wet lands; - Rotate grazing areas; - Use of toilets / avoid bush toilets; - Rest paddocks; - Drain swampy areas - Inspects meat; - Thorough cooking of meat; - Dose animals with trodax/ ranide. - Ploughing/ cultivation of pastures; For a named internal parasite of a non-ruminant animal; (a) Describe the life cycle, Tape worms : Taenia solium Life cycle: - Adult produces eggs in human beings; - Eggs passed out through faeces; - Develop into onconspheres - Eggs ingested by the pig; - Hatch in the intestines; - Embryo penetrate intestinal wall; - Enter blood stream; - Enter into the liver/ heart/ lymphatic; vessels; - Cycts/ measles in muscles; Diagram (b) Describe the methods of control. - Dose animal; e.g Ranide - Meat inspection; - Meat properly cooked; - Proper disposal of faeces - Use of toilets - Fencing wet areas; - Rotate grazing areas - Rest paddocks - Drain swampy areas [7] [10] [5] Outline the effects of internal parasites in a ruminant animal. [8] - Anaemia/ loss of blood; - Irritation; - Bottle-jaw - Pot belly; - Rough skin, - Loss of mass - Low production; 102 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Loss of appetite; Diarrhoea; Vomiting Discuss the importance of the animal Health Act. [8] - Identifies notifiable disease: foot and mouth; anthrax and Newcastle - Permits/ restriction of animal movement; - By vet department and immigration officials - Allows vaccination for foot and mouth - Dipping - Gives guide lines for disposal of carcass - By burning or burying of carcass. State four advantages of using plunge dip when controlling an external parasite. [4] - Useful with a large herd of cattle; - Low labour costs; - Acaricides can be used again; - Animal is fully immersed; - Operational costs are low; Outline legislation on dipping cattle in Zimbabwe. Summer: once per week; Winter: once per fortnight; [2] Explain the importance of the dipping legislation you outlined in question above, [4] Summer: incidence of ticks would be high; Reduces tick-borne disease related mortality; Winter : low incidence of ticks; Low mortality due to tick-borne diseases Explain how rotational grazing help to control ticks in livestock. [4]  Main host tick removed;  Tick life cycle broken;  Ticks fail to find host;  Ticks die of starvation; ********************************************* SUB TOPIC: ANIMAL IMPROVEMENT ********************************************* Genetics  Explain genetics terms  explain the stages in mitosis and meiosis  outline the effects of the environment on genes Genetics - genetics is the science that studies how heritable characteristics are passed from parents to their offspring. 103 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - animal improvement is based on heritability or ability of a characteristic to be passed on from generation to generation Important terms used in genetic studies and breeding 1. Gene – it is the basic unit of inheritance that influences characteristics - Genes are found on chromosomes - They are the smallest segment on chromosomes - The major function of genes is to maintain identity from one generation to another 2. Locus – the position of a specific gene on a chromosome 3. Allele – it is an alternative form of gene 4. Chromosomes – these are thread-like double structured strands of nucleic acids and protein found in the nucleus of living cells which carry genetic information (genes) 5. Genotype – the genetic makeup of the organism for a specific characteristic 6. Phenotype – it is the outward appearance of an organism - It can also be described as the observable characteristics or measurable characteristics of an animal such as coat colour and milk yield 7. Dominant gene – a gene that masks the effect of another - Dominant genes show their effect even if only one copy of the allele is present, for example, an animal will have a black coat colour even any other allele is present - A dominant gene is always represented using a capital letter for example Bb, capital letter B will represent the dominant gene 8. Recessive gene – a gene whose effect is masked by the presence of the dominant gene - Recessive genes only show their effect if an animal has two copies of the allele, for example bb for brown colours 9. Heterozygous – it is a situation where there is one dominant and one recessive gene in an organism, for example Bb. Such an organism is called a heterozygote. 10. Homozygous – is an organism carrying two similar alleles on a gene locus, for example BB or bb MITOSIS AND MEIOSIS - in organisms cells are always dividing, and cell division is a highly organised precise process. There are two forms of cell division: 1) Mitotic division which is mainly for growth and repair of tissue 2) Meiotic division which is cell division for production of sex cells or gametes (sperms, egg). - - in genetics, study is focused on how genes (factors controlling characteristics) influence outward appearance and how the genes are shared during cell division to maintain certain characteristics to come up with new combinations of characteristics in organisms. animal improvement is based on genetic understanding as the basis of any manipulations that can be done on organisms to result with desired characteristics for improved production. 1. Mitosis - it is the division of cell nucleus into two daughter nuclei that are identical to another and to their parent nucleus 104 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - this is a type of cell division that maintains the number of genetic material and is for growth and repair of tissue mitotic division is important in reproduction of asexually propagated plants (plants that grow from old parts without male or female parts being involved) mitosis occurs in four stages which are: 1. Prophase chromosomes become thicker and shorter they appear as two sister chromatids which are held together at the centromere the nuclear envelope disappears chromosomes move to the equator spindle fibres become visible (leave 8 lines for diagram) 2. Metaphase - spindle fibres attach to centromere pulling sister chromatids apart (leave 8 lines for diagram) 3. Anaphase - describe what happens during anaphase of mitosis. [4] centromeres of each chromosome divide into two equal parts; two chromatids of each chromosome move apart; chromatids become bent like hair pins; chromatids move to opposite poles; daughter chromosomes produced. (leave 8 lines for diagram) 4. Telophase - two daughter nuclei are formed nuclear membranes reform as chromosoomes uncoil spindle fibres disappear (leave 8 lines for diagram) Importance or significance of mitosis 1. helps to maintain genetic stability by keeping the same number of chromosomes from generation to generation 2. helps to repair damaged and worn out cells 3. brings about growth through increase in cell membranes 4. enables asexual reproduction in plants 105 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Meiosis - it is a form of nuclear division in which the chromosomal number is halved from diploid (2n) to haploid (n), hence it is called reduction division - meiosis occurs in sex cells only - it results in the formation of four daughter cells Stages of meiosis First meiotic division 1. Prophase 1 2. Metaphase 1 3. Anaphase 1 4. Telophase1 Second meiotic division - this second stage of meiosis is similar to mitosis 1. Prophase 2 2. Metaphase 2 3. Anaphase 2 4. Telophase 2 Significance of meiosis i. Results in the formation of sex cells (gametes) ii. Brings about variation in organisms through crossing over and random assortment Differences between mitosis and meiosis Mitosis Meiosis Effects of environment on genetics - the environment may change the phenotype (observable characteristics) of an organism. For example, if two genetically identical organisms are kept separately in two different environments, their phenotypes may not necessarily be the same - degree of expression of a gene can be influenced by the environment. Environmental factors that affect phenotype may include: • • • Nutrition (amount and quality of feeds) Disease prevalence Climatic factors like temperature and rainfall ********************************************* 106 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 SUB TOPIC: ANIMAL IMPROVEMENT Breeding      explain the importance of breeding explain the effects of the environment on breeding distinguish cross-breeding from in-breeding select animals for breeding Importance of artificial selection Breeding - It is the controlled production of groups of animals, whose parentage is known for the purpose of increasing number of animals/improving characteristics of animals. Reasons of breeding/improvement Explain four reasons why a farmer would improve the breeds of his animals. [4]       To achieve high milk yield To improve growth rate To improve meat to bone ratio To improve resistance to diseases To improve adaptability to different climatic conditions. Improve resistance to pest attack; Selection - It is a process of choosing which animals to use for mating. - Discuss the factors considered by a farmer when selecting a young animal for breeding. [6]  Growth rate;  Conformation/ wedge shaped;  Fecundity/ fertility;  Milk production; big milk veins; high butter fat milk;  Resistant to disease;  Tolerance to drought;  Resistant to hash conditions;  Food conversion ratio/ efficiency; - Describe the desirable breeding characteristics of a female ruminant animal. [5] - Describe any four factors which should be considered when selecting a male animal for breeding. [4] - Explain how animals are selected for breeding. [4] Breeding system (a)Inbreeding - Is mating of closely related animals e.g. father and daughter, mother and son or brother to sister. Advantages - Desirable traits are continually passed in the family - Helps in developing uniformity 107 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Disadvantages - May concentrate undesirable traits - Animals may end up with reduced vigour in some traits. (b)Cross breeding - Involves mating purebred animals with different breeds e.g. Mashona cow and Brahman bull. Advantages Explain any three advantages of cross breeding in animal production. [3] - Offspring shows improved performance; - Combined desirable traits from parents; - Animal is superior to parents / hybrid vigour; - Resistant to diseases / pests - Improved growth rate / improved performance Selection of animals for breeding methods.  Progeny quality  Individual selection. ********************************************* TOPIC 5: FARM STRUCTURES AND MACHINERY ********************************************* SUB TOPIC: FARM IMPLEMENTS ********************************************* Maintenance  describe routine maintenance of farm implements - plough, -cultivator -harrow Farm implements maintenance Importance of farm machinery maintenance - Well serviced and maintained machinery results in timeous operations on the farm due to reduced breakdowns - Efficient management and operation of farm machinery offers better opportunities for cost saving and improved productivity - Farm machinery maintenance guarantees positive return on capital investment on the machinery. Poor or inefficient operations are costly in terms of value invested on the machinery 1.The Plough - it is responsible for turning, inverting and pulverizing the soil 108 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - the plough is made of carbon steel or cast iron the plough has its different parts bolted together it cuts, loosens and inverts the soil depth of ploughing depends on crop root development, rainfall, soil texture and availability of draught power due to the nature of the work it does, there is need for regular maintenance of the plough by the farmer Mouldboard Functions of parts of a plough  Share. Cuts the furrow slice.  Lanside. Keep the plough in contact with the cut edge of furrow.  Mouldboard. turns the furrow slice over  Hitch assembly. Used to adjust depth of plough and width of cut.  Handle bars. Control the plough.  Wheel. Used to adjust plough depth.  Beam. Is where all parts of a plough are attached. November 1996 21.a. With the aid of a labelled diagram, identify the parts of a mould board plough? b). Describe the functions of any three parts of a mould board plough. Possible Answers With the aid of a diagram, identify the parts of a mould board plough. 109 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Describe the functions of any three parts of the plough. Part Functions Beam holds other parts of the plough Hake fixing parts of the plough which are adjusted before and during ploughing depth rod adjusting depth of ploughing/ vertical adjustment draft rod pulling the plough / draw bar link linking the plough on to a chain pulled by oxen wheel maintain depth of the plough reduce resistance while ploughing/ steadying the plough braces stabilize plough frog where lanside/ share/ mouldboard are attached landside stabilize plough share mouldboard cuts furrow slice/ penetrates soil turning furrow slice/ burying vegetation hitch assembly adjusting depth/ width of ploughing links plough to chain handles for operator to control plough clamp holds wheel arms to beams 110 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 wheel arms holds the wheel axle connects wheel to arms/ where wheel turns bolts and nuts for joining different parts Depth adjustments a) Depth - For shallow depth-lower the depth rod and tighten the set screw. - For a deeper cut- raise the depth rod and tighten the set screw b) - Width of cut For a wider cut, move the depth rod to the left hand side. For a narrow cut, move the depth rod to the right hand side. Plough maintenance - Replace worn out parts - Tighten bolts and nuts - Clean the plough after use. Plough storage - when field operations with the plough have been completed, store the cleaned, repaired plough in a protected dry place 2.Cultivators - cultivators are also known as tillers - these are implements which stir the land and break up furrow and clods left by the plough - they destroy grasses and weeds that grow after ploughing by uprooting and exposing them to sunlight where they dry up - a cultivator consists of a frame with a number of tines for breaking and mixing the soil. The tines have replaceable shares or points and various designs are used for different types of work - working depth is generally controlled by a tractor hydraulic system - some tined cultivators have a crumbler roll attached at the rear which helps to break up clods Maintenance Placement of tines • Worn out tines should be replaced • Tines should be properly adjusted and tightened • Oiling and lubrication of movable parts should be done when necessary • Trash trapped on the implement must be removed after use and before storage 111 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 • Store in a safe dry place Describe adjustments that can be done on a cultivator when weeding. [7]  Use width control lever; adjust forward or backwards;  To increase / narrow width;  Lengthen chain to increase depth;  Shorten to decrease depth;  Adjustment of holes to decrease / increase depth;  Use tines / ridgers;  Reduce / increase number of tines. 3.Harrow - a harrow is a universally used implement and is as old historically as the plough - the main function of the harrow is to sort out clods of varying size, leaving the unbroken large size clods on the surface. Its action causes the smaller particles to filter downwards thus leaving the larger ones on the surface - the harrow is very effective in destroying small weeds that are just starting, it is also useful in covering broadcasted seeds and in breaking crust - the spring tines are bolted and staggered on the frames to avoid clogging during its operation - There are two types of harrows: 1) Disc harrow 2) Tine harrow Maintenance of a disc harrow - a disc harrow is a land preparation implement drawn by a tractor. It is mainly used for secondary tillage operations and conservation tillage practices. - the disc harrow can be used to pulverize soil, break clods and for levelling of fields • • • • • Bearings must be thoroughly greased at regular intervals All the nuts and bolts must be checked and tightened where necessary daily before taking the implement to the field Blunt edges of the discs should be sharpened regularly During the slack season, the worn out parts including the bearings should be fully replaced It is better to coat the outer and inner surfaces ,of the discs with oil or paint when the harrow is lying without use in slack season Maintenance of tine harrow - tine harrow is an implement used to level land and to remove trash from the fields. Sometimes it can be used to cover sown seeds - the tine harrow is much lighter than the disc harrow and can be tractor or animal drawn • • • • Tighten the tines or teeth daily after use Blunt edges of the tines should be sharpened regularly Replace damaged tines It is better to coat the surfaces of the harrow when the harrow is lying without use in slack season using old engine oil or paint 112 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 November 1996 20. Outline the maintenance required for the following implements a. cultivator b. planter c. harrow Possible Answers Question the maintenance required for the following implements. i). Implement cultivator maintenance - check shares / tines for wear and tear - tightened bolts and nuts - painting/ oiling / greasing - cleaning after use - storage in shade, replace worn out parts - lubrication ii). planter - lubrication - cleaning soil from coulters - painting / oiling/ greasing - cleaning after use - storage in shade, replace, worn out parts - lubrication iii). Harrows, disc harrows - lubrication of bearings tighten bolts and nuts paint/ oil/ grease when out of use to prevent rusting after use, store in shed iv). Spike tooth harrow - check that pegs (teeth) are tightly clamped on frame - - replace or sharpen damaged pegs - check on condition of points sharpen points by grinding ********************************************* SUB TOPIC: FENCING ********************************************* Treatment of fencing materials  describe the treatment of wooden fencing materials  describe treatment of metal fencing materials 113 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 FENCING - a fence is an erect structure or barrier that is constructed to make boundaries for security and for restricting animal and people movement fencing is important in farms where mixed farming is practised as it enables cropping and livestock rearing to be practiced on the same farm without damage to crops by stray animals a fence can be made out of barbed wire or mash wire with wooden or metal erect posts. Live hedges, stone walls and grass thatch can also be used as fences metal and wooden poles are commonly used in wire fences. However, these require special treatments to make them last longer by making metal withstand rust and making wood withstand termite attack - - Treatment of fencing materials 1. Wooden poles - wooden fencing poles should be treated so that they become more resistant to termite attack - treating also improves their durability - creosote is the most commonly used chemical for treating wooden fencing poles the following procedure may be used to treat wood: i. Poles cut from the field are debarked (barks stripped off) and immersed in water to remove cell sap (cell fluids) ii. The poles are allowed to dry naturally iii. They are then immersed in creosote and boiled for several hours. This allows the creosote to soak into the wood iv. The treated poles are then allowed to cool and dry under shade for slow drying and to give more time for the wooden plant cells to absorb more of the chemical - other chemicals such as grease or tar oil can also be used to traet wooden fencing poles 2. Metal fencing poles - metals poles are treated by coating or painting to improve rust resistance - coating or painting creates a surface layer that prevents contact of the metal with external conditions that cause metal rusting (moisture and oxygen) - coating of metals is usually done to metals prone to rusting by coating them or applying a layer of a rust resistant metal such as copper, alumininium and stainless steel - painting is done by first applying a layer of undercoat paint followed by applying a surface layer of paint using a brush or through spraying - oil paint is used to protect metal from rust. The more the number of layers of paint coats, the greater the protection. Painting is more effective if repeated over with time. ********************************************* Fencing specifications  Describe the standard specifications of fencing on farms  Fencing specifications: -spacing of poles -spacing of strands 114 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Spacing of metal posts and wire strands - wire and wood or meatl fence should have standard materials and should be constructed using general spacing guidelines for strength and security - wire fence is made of standards which are wood or metal posts erected at regular intervals of 1.8 – 2 metres apart with about 75cm of the post buried to the ground - generally, four strands of barbed or plain wire are nailed to wooden posts using ‘U’ shaped nails or tied to metal using soft but strong plain wire. Strands of wire can be increased to more than four depending on the level of security required - to prevent wire strands from sagging, droppers are tied to the wire strands suspended. The droppers are smaller in diameter and are usually of treated wood or metal Spacing of standards, droppers and wire strands 1) Standards - Standards are timber or metal pieces used as upright posts in erecting farm fences. - the length and diameter of the posts varies and their selection depends on height of fence required - corner posts are usually thicker forms of uprights - standards can be spaced 1.8 metres to 2 metres apart 2) Droppers - these are wood lengths of 50millimetre diameter suspended between upright posts stretching from the highest to the lowest strand. Thinner metal is sometimes used as droppers - spacing of droppers is usually two to three droppers between two uprights. - Droppers are attached to wire strands using soft wire - their purpose is to prevent sagging of wire (leave 10 lines for diagram) ********************************************* Anchors and fencing calculations  explain the role of anchors  outline the advantages and disadvantages of different anchors  determine the quantities of materials required per given perimeter 3) Wire anchors - these are structures on the fence meant to make the wire resist movement in the direction of strain - movement of the fence in the direction of strain results in the wire strands sagging, compromising security offered by the fence a) High gate post anchor – this anchor helps to strengthen poles on gate openings. The poles experience straining pull in opposite directions and therefore have the tendency to move apart in opposite directions -the wire tied to the posts makes the post resist strain pull 115 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 (leave 8 lines for diagram) b) Double wire anchor – double wire anchor is used for strengthening corner posts which is pulled by two straining pulls that act right angles. The straining pull will cause the corner post to lean forward into the field causing wire strands to sag -the double wires tied to corner posts are tied to big rocks or steel pegs to make the posts resist strain pull and remain in position (leave 8 lines for diagram) c) Double box anchor – the double box anchor is used where the fence stretches over long distances -these are placed at regular intervals along the length of the fence and help the central part of the fence withstand sagging -it is just like the high gate post anchor except that the wire strands cross the anchor posts in a double box anchor. This makes the double box twice as strong ( leave 8 lines for diagram) d) The stay anchor – the stay anchor is usually used on wider gate openings that should allow heavy vehicles to pass through. In such situations, the high gate post anchor is not applicable -usually a metal piping or rod is bolted to the gate post at a 45 degree angle and the metal is buried to the ground in the direction of the strain to resist movement in the direction of strain (leave 8 lines for diagram) ********************************************* SUB TOPIC: FARM BUILDINGS ********************************************* Farm buildings  identify materials used for the construction of farm buildings  describe the properties of building materials  Properties of building materials such as: - Quality - Durability - Strength - Fire resistance - Termite resistance - Temperature resistance 116 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 FARM BUILDINGS - building or construction is an industry where regulations are set by the local authority or body, such as a council or municipality to ensure that the buildings are built to a certain acceptable standard of construction - procedures have to be followed to ensure safety of occupants, users, passers-by or those who work in the vicinity - brickwork involves the use of different materials and tools to erect a wall. Brickwork is a process of producing accurate walls according to plans. - the construction of farm structures is guided by agricultural principles and modern trends in research - some farm structures can be constructed using locally available resources like wood, thatch grass and stones. However larger buildings would need steel and concrete as construction materials - buildings built on the farm must be to specified standards for them to serve the intended purpose efficiently and at minimum cost Purpose of farm buildings - all buildings on a farm have specific purposes. They may be used to shelter farm animals and poultry as well as to store farm produce - the structures include water tanks, pig sties, water troughs, dairy palours, sheds, irrigation canals, silage bunkers, tobacco barns, silos, blair toilets and so on BUILDING MATERIALS 1.Sand - there are two common types of sand, river sand and pit sand. a) River sand – is used for mixing concrete and outside plastering. River sand can be obtained from river banks. Clay and other dust particles must be removed from river sand by washing. b) Pit sand – is known as fine aggregates. Pit sand is used to plaster interior of buildings. It can be obtained from pits but should be free from top soil because it weakens the structure. If the pit sand is not clean, it is screened to remove the organic impurities like decayed plant matter. Screening is done by passing sand through a wire screen. 2.Quarry stones or gravel - quarry stones and gravel are known as coarse aggregates and are used for concrete making. a) Stones – are used because of their strength, durability and in some cases availability at low cost. They, however have limitations as they are unavailable in some localities. Where they are available, they are difficult to shape into blocks for construction. b) Gravel – must be screened to remove fine aggregates and organic impurities. The impurities weaken the structure as they do not have the same properties as those of the stones. Organic material may decompose leaving cavities within structures and these will be weak areas on the construction. 3. Cement - cement binds particles together to form a strong structure. One important property of cement is that once it has set, the process is irreversible. 117 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - cement is very ideal for construction in wet areas or where there is need for water proof structures since cement structures do not dissolve in water for centuries. the constructions made with cement are highly durable structures if the mixtures of cement, sand and concrete are done properly. cement is the binding material (matrix) which binds aggregates together. Aggregates refers to the sands, gravel, quarry stones that are mixed with cement and water to produce concrete. cement is made by burning a mixture of clay and chalk (or limestone). For example, ordinary portland cement is one part clay and three parts lime. Properties of cement - cement makes structures with high levels of strength. The structures can withstand a sizeable amount of load and compressional forces. Some cement types have the advantage that they can be used in wet conditions and can still set to strong structures such as in bridges. - Portland type of cement hardens by a chemical reaction when mixed with water (hydration). A paste of cement and water first undergoes gradual stiffening, called setting, but the hydration continues long after the paste has become rigid. This results in a progressive increase in strength called hardening. Cement types • • • • • • • • Ordinary Portland cement: with a ratio of 3:1 (limestone:clay) Rapid hardening cement: it is ground to a finer powder for faster setting. It is used where a faster rate of strength gain is necessary such as in a bridge or dam construction. Extra rapid hardening cement: useful in temperate zones where winter weather conditions affect construction works Low heat Portland cement: this type is recommended for mass concrete work such as dams and where trapped heat would cause damage to the concrete Sulphate resisting cement White cement Coloured cements Masonry cement 4.Bricks Types of bricks a) Common bricks: these are general purpose bricks used where appearance is not a factor. They are porous and cheap. b) Face bricks: these are used on exposed surfaces where appearance is a factor c) Engineering bricks: these are bricks used as decorative bricks. They are very hard and smooth in texture with a high load bearing capacity. Engineering bricks are used for constructing bridges, durable and moisture resistant structures. d) Fire bricks: these are refractory to heat. They increase temperature resistance and are used in fire places. e) Insulation bricks: they have heat insulating ability. They are used in industrial furnaces f) Cement blocks: these are made of cement and sand. They double measure brick walls internally and externally. They cover work faster as they are light and of bigger size compared to ordinary bricks. They have poor heat transfer and are used in cavity walls. 118 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 5.Wood -this is a cheaper and readily available material used in farm constructions. - • Wood is versatile. It can be easily cut to size. • It has limited strength under load. • It is light and therefore is used to support roofing material However, wood is prone to termite attack and therefore requires treatment 6.Metal -it is used as a reinforcement material in concretes and in framework construction. -metal sheets are used as roofing material • • • • Metal has high tensile strength; thus it can withstand heavy loads and shearing forces Metal is resistant to fire and termite attack but susceptible to rusting. It therefore needs galvanising, painting or coating. It is durable. It lasts longer. Metal is relatively expensive. 7.Grass - grass is used for roofing as thatch and can also be used as fencing material. Grass is relatively cheap and locally available in most areas It is susceptible to fire and termite attack Factors to consider when selecting building materials a) Stability -the material to be used should be able to support loads, lateral forces and expansions due to temperature and moisture changes. The material should therefore remain stable in the face of forces and conditions acting on it. b) Strength -the material should be able to support its own weight, wind loads and loads imposed by other materials used in the structure. The strength of a structure depends on the strength of the materials used. c) Exclusion of rain -the ability of a material to exclude rain will depend, to some extent, on its exposure to wind and rain d) Durability -durability depends on characteristics or properties of the material. Durability is the ability of the material to endure an exposure to harsh and trying conditions. e) Termite resistance -it is the ability of a material to resist termite attack and exposure f) Fire resistance 119 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 -material that is fire resistance can withstand fire attack and exposure for a prolonged period of exposure before catching the fire. -resistance to collapse, flame penetration and heat transmission during a fire should take half an hour to six hours. g) Thermal resistance -this is the rate at which heat flows through a part of a building. It is determined by the thermal conductivity of the material and the thickness of that material. The material to be used should have adequate thermal storage capacity. The internal face of walls should be at a reasonable temperature. ********************************************* Designing livestock buildings    draw plans of buildings suitable for livestock calculate costs of construction determine the cost effectiveness of each material Factors to consider when selecting a site for a farm building . - Slope of the land(site topography) - Wind direction - Distance from homestead(closeness to connections) - Size of the building - Availability of water - Drainage of the soil - Firmness of the ground - A clear site - Accessibility Properties of building material. - Good insulation property - Should be able to give protection of materials, equipment , animals against rain and adverse weather conditions - Should be easily renewable - Should be easily obtainable - Should be easily available - Should not be expensive - Should be durable - Easy to work on - Should be cut to usable sizes - Not brittle under heavy loads Types of materials and their uses. (i)Timber(wood) . - Used to construct various farm buildings - For making roof of buildings - Used as fencing posts, rails, kraals poles , and dagga structures 120 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Advantages of wood  Cheap  Readily available  Strong if treated  Can be cut to different sizes by the user Disadvantages of wood  Can be destroyed by termites if not treated  Not strong under heavy loads (limited strength)  Can de burnt by fire destroyed completely  Has limited life spun due to decay (ii)Metal (iron steel). - Can be iron or steel - Can be used as fencing, posts roofing posts, supporting posts and reinforcing concrete - Making doors and window frames Advantages of metal  Strong  Very durable  Cannot be destroyed by fire  Cannot be attacked by insects (termites, borers) Disadvantages  expensive to buy  not locally available  can be affected by rust (iii)Thatch grass.(Hyperhenia) - Common building material in rural areas and commercial farms - Used as roofing material for houses, sheds , livestock houses , granaries , calf pens , goat houses - Can be used combed or uncombed - Combing increase durability and life spun on buildings Advantages of thatch grass  Cheap  Locally available  Provide good insulating property compared to zinc or iron sheets Disadvantages  Can be destroyed by fire  Prone to termites , rodents , and livestock attack  requires more labour to fetch thatch grass , to comb and thatch the building (iv)cement - Used for making concrete - Mixed with mortar used during building construction to bond bricks Advantages of cement  Very strong  Strengthens buildings Disadvantages  Very expensive to purchase  Not readily available (v)Soil 121 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - Used to making mortar for binding bricks Mortar – is a mixture used in brick laying or block laying to bind the bricks together - Is made of 1 part cement and 4 parts loam soil / sand - Bricks to be mortared should be wetted first - Can be used for the construction of huts , granaries (pole and dagga huts) - Can be used to make common bricks especially anthill soil Advantages of soil  No costs are incurred to buy soil  Locally and readily available  Good insulating property ( buildings are cool inside ) Disadvantages of soil  Swells and shrinks upon absorbing water and on drying  When used as plastering external walls it can be washed off( eroded)by rain water  Structures can collapse due to high absorption of water by soil (vi)common farm bricks - Are made on the farm using ant heap soil which is made into paste using water and put into moulds firmed and emptied then dried - Used for construction of many farm buildings Advantages  Easy to make  Cheap  Strong and durable if burnt  Resistant to moisture resistant when burnt Disadvantages  Need a lot of labour to make  Leads to deforestation as trees are cut to cure bricks  Need plastering to increase durability (vii)concrete block bricks - Used for making building foundations - Are mixed using cement mixed with coarse river sand and (stone aggregates or quarry) - The mixture is put into moulds firmed and emptied then left to dry - Concrete blocks are not burnt Advantages  Very strong and durable  Fire resistant  Have good insulating property  Less bricks are used to construct large structures as compared to farm bricks  Faster to use than farm bricks because they are bigger Disadvantages  More expensive to make than farm bricks  Are heavy to lift during construction (viii)Faced /glazed bricks - Are used for decorating farm buildings (ix) zinc/iron roofing sheets - Made of zinc or iron 122 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - The sheets are placed overlapping during roofing to give full protection from the rain Advantages  Strong and durable  Offers good full protection against rain Disadvantages  Have poor insulating properties (heat quickly in the sun and this makes the building very hot inside ,when cool they catch a lot of cold))  Iron sheets tends to rust (x)asbestos - Is a hard roofing material made of asbestos - Are nailed to timber using special roofing nails or screws Advantages  Offers maximum protection against rain and adverse weather  Good insulating property Disadvantages  Break easily  Continuous working and holding leads to development of asbestosis illness Note: Material to be used for construction of a building will depend on what is locally available on the farm ********************************************* SUB TOPIC: FARM ROADS ********************************************* Features of farm roads  describe features of a farm road  state the dimensions of different features on a farm road FARM ROADS - farm roads are very important in day to day farm operations and it is of paramount importance that they meet certain standards and specifications. Characteristics of a good farm road • • • • • • Safe and accessible all year round Must be wide enough (roads to the field must not exceed 4metres in width) Road shape must be cambered to facilitate drainage on road surface The road must be easy to maintain The road must be well drained to minimise damage by erosion and free from muddy water pools In erosion prone areas, drainage features must be gentle to a gradient of 1:200 123 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 The road dimensions and shape (leave 8 lines for diagram) Road gradient - road gradient should not exceed 1 in 20 for loaded vehicles especially during wet weather as theis becomes a hazard. - in the eastern highlands areas such as Nyanga, Honde Valley, Chimanimani and other places roads can be as steep as 1:12 and cannot be used in wet weather. Features for farm road drainage 1.Side drains - farm roads should have side drains that collect water from the road crest. The side drains should have mitre drains at one metre vertical interval - the drains should be dish shaped or wide at the bottom to minimise erosupion. The drains can also be grassed to reduce erosion and maintenance costs. (leave 8 lines for diagram) - where the road is not on the crest, there might be need to move or divert water from the upper to lower side of the road. This is achieved by using culverts and inverts, with inverts being the cheaper option. 2.Culverts - culverts are built structures with buried concrete pipes that divert water across the road from an upper slope to the lower side of the slope. (leave 8 lines for diagram) 3.Inverts - inverts are shallow depressions made of cement and concrete flat slabs built on road surface to allow water to flow across the road without damaging the road through erosion. (leave 8 lines for diagram) 4.Bolsters - gently sloping banks of gravel built across the road can also be used to divert water from one side of the road to the other. Bolsters can be part of contour ridges in arable land. (leave 8 lines for diagram) Farm road maintenance - farm roads require regular maintenance and care from time to time to keep the roads safe and accessible - heavy vehicles and machinery may damage the roads during operations, by creating tracks and furrows that may lead to erosion during the rainy season 124 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 - - drainage structures need to be maintained by clearing weeds that may block water ways so as to check erosion. However, grass should not be completely removed from water ways but cut short to maintain soil cover. farm roads need to be graded to keep the surface smooth and to maintain the camber shape for facilitation of drainage the road crest must always be dry in wet seasons to avoid muddy conditions laterite gravel may be needed from time to time to fill in potholes that may develop with time it is sometimes necessary to wet the roads with a water bowser during dry seasons to minimise erosion by wind currents, generated by moving vehicles. This also helps to reduce ripples developing on the road surface ********************************************* Road construction and maintenance    identify materials required for the construction of a farm road describe the construction of a farm road maintain local farm roads FARM ROADS KEY CONCEPTS  Farm roads ensure a good transport system in the farm  Roads enable a farm to become easily accessible , thus inputs can be delivered easily into the farm  Good farm roads reduce transport costs and minimise break down of farm vehicles  Farm roads need to be correctly sited and properly maintained Factors to consider when sitting a farm road  Topography  Nature of the area  Soil type  Slope  Physical features  Position of paddocks Equipment needed when sitting roads Dumpy level(kern level)  For levelling the road surface and determining the gradient along the road area during the sitting of the road Wooden pegs  To mark the edges of the road Mattock  For digging and stumping trees and shrubs on areas where the road is to be constructed Axe  Cutting and chopping felled trees Hammer  To drive wooden pegs into the soil when marking edges of the road and for breaking rock out crops 125 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Pruning saw  For cutting tree branches protruding on the road Rammer  Heavy iron roller wheel used for firming gravel applied on the road surface Shovel  Used for removing soil from the mitre drains during mitre drain construction Tape measure  Used for measuring the width of the road and dimensions of the mitre drains Characteristics of good farm roads  Cambered (sloping towards edges)to drain water out of the road  Should be wide enough to allow two vehicles to be able to pass each other in opposite direction  Must be well firmed so that tractors and vehicles do not get stuck during the rainy season  Should slope gently to avoid soil erosion  Should be all weather road usable all year round  Should be straight to reduce distance and cost of fuel incurred when the road is meandered Farm road features Mitre drains  Are drains constructed (dug)on the road sides which take away (drain) water flowing on road sides to well grassed area  Mitre drains spill water from road to waterways  Spacing of mitre drains depends on gradient (slope) on the section of the road and the type of soil whether its prone to erosion or not (i)Cambered road (road crown)  Cambered road is a road whose crown is raised above ground level so that it drains away rain water from its surface . 126 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  A road should not be flat on the surface but cambered to drain water on the surface so that the water then flows into mitre drains. Cambered road (ii)Drain bolsters  Drain bolsters are structures of cemented stones piled together on road sides where mitre drains join the road which helps to divert water into mitre drains . (iii)Culverts  Are drainage pipes made of reinforced concrete which are placed (put) across a road  Allow flood water to cross the road underneath  Pipes are built under the road  The drainage pipes are cemented together and concrete and stones are put on top of them to level the surface .  The pipes must be very strong to with stand weight of vehicles and tractors 127 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 (v)inverts  Are concrete slabs or stone mansory laid on road surface on low lying water course so that water will flow across the road over it without causing soil erosion on the road section .  Water flows on topof the concrete slabs (vi)Road width  Farm roads should not be too wide because the volume of traffic is not much and it is also a cost saving measure .  The majority of farm roads are 3 metre wide . FARM ROAD CONSTRUCTION MATERIALS .  Gravel  Cement  Coarse sand  Stones  Coarse and fine sand Construction of farm roads a)Timing  Farm roads should be constructed during the dry season (winter )when labour demand and tractor operations on the farming activities are less  The best time to construct farm roads is from May , June ,July ,August and September when its not raining  During the rainy season tractors , graders ,and other machinery can get stuck in the mud b)Pegging /sitting  start by pegging the road and size by placing wooden pegs where you expect the edges to be .  a dumpy level (kern level) machine is used to establish gradient and align straightness of pegs during pegging . c)Clearing trees and shrubs  after marking the road , all trees and shrubs must be cleared off by stumping and cutting down using mattocks ,axes or machetes d) Ploughing  ploughing is done on where the road will be , so as to loosen the soil so that when the soil is compacted , it will be firm . e) Grading  A grader can be tractor towed or self motorized 128 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  A grader is used to raise soil from road sides to make cambered road and to level the road surface  A grader is also used to construct mitre drains  A grader is also used to close potholes on roads f)Surfacing and ramming  gravel or laterite is put on the road surface and spread over the road .  gravel/laterite can be ferried from elsewhere using tipper trucks or tractor drawn trailers .  after putting gavel , the materials must be strongly rammed using tractor drawn rammers  ramming compacts the soil and makes the soil firm Maintenance of farm roads  Grading the road up and down to maintain slope and crest .  Opening up silted mitre drains ,culverts and inverts .  Straighten drain bolsters  Fill potholes with gravel  Re- surfacing the road with gravel when necessary  Planting grass strips on road sides to prevent soil erosion  Keeping shape /camber shape of the road to drain away run off . ********************************************* SUB TOPIC: APPROPRIATE TECHNOLOGY Appropriate technology-is also referred to as intermediate technology It referrers to simple technology that suits the prevailing farm situations. it varies from simple to advanced farm machinery the ability of farmers to purchase a certain tool measures the appropriateness of a technology ********************************************* Irrigation pumps  identify parts of a hand or power operated irrigation pump  discuss the working principles of an irrigation pump  describe the routine maintenance of a pump ********************************************* Shellers    identify parts of a maize and groundnut Sheller explain functions of each part explain operational principles of Shellers Shellers  Are machines used to thresh maize grains from the cob or which are used to remove ground nut seeds or cow pea seeds from pods 129 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Maize Shellers It can be hand operated , pedal driven or driven using electric motor It consists of a drum ,revolting threshing pedal with beater bars placed in a drum , concave plate ,a sieve ,fan blower ,feeding conveyer belt and grain chute .     MM+ Maize is placed on cobs feeding conveyer –belt in an electric motor driven sheller and the cobs will be drawn into the drum where threshing will occur . For hand operated or pedal operated shellers, maize is put into the drum where threshing occurs using hands . As the revolving threshing drum with beater bars rotates , it will squeeze the cobs against the concave plate resulting in maize grains being removed from the cobs . The grain falls through a fan blower which blows air to remove away chaff and grain will collect into the grain chute . 130 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  A fan blows air through the threshed grain which cleans the maize grain by removing chaff , pieces of husks , weed seeds ,and then maize grain is bagged . Groundnut sheller .  Is used to remove groundnut seeds from shells .  It consists of beater bars which are fixed on a handle , half cylinder wire mesh screen and metal iron box where groundnuts are placed during threshing  Groundnuts to be shelled are put using hands into the metal iron box .As the metal rod handle is moved or pushed forwards and backwards , the oscillating 131 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 beater bars will rub or squeeze the groundnuts against the wire mesh screen resulting in pods breaking and are collected at the bottom of the metal box . ********************************************* TOPIC 6: AGRI-BUSINESS ********************************************* SUB TOPIC: PRINCIPLES OF ECONOMICS ********************************************* Opportunity cost and choices  explain the opportunities available for the farmer in agriculture industry  describe the factors influencing farmers` choices in agricultural enterprises  explain the concept of opportunity cost Opportunity cost and choices - the opportunities which are available to the farmer in agriculture industry are quite variable. These can best be summarised by the different branches of agriculture which include: 1.Crop production - there are many different types of crops that a farmer can decide to produce depending on a number of factors that will be explained later. - the different types of crops include: a) Cereal crop – maize, wheat, sorghum and others b) Legume crop – groundnuts, field beans, soya beans etc. c)Horticulture or market gardening- vegetable, flower or fruit production 2. Livestock production - broilers, layer birds, rabbits, dairy and beef cattle production 3. Forestry and Wildlife management 4. Agri-business management 5. Crop and animal breeding 6. Research and extension 7. Processing of agricultural products Factors influencing farmers’ choices in agricultural enterprises 1. Available land - This refers to the size of the land, type of soil, topography, fertility, drainage and others. All these have direct and indirect effects on the choice of an enterprise the farmer can pursue. - Fertile, well drained soils are generally suitable for crop production while less fertile lands can be used for either livestock, forestry, wildlife or any other branch of agricultural enterprise. 132 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 2. Climate - This generally refers to mainly rainfall and temperature. Different crops and livestock are suitable for different climatic conditions. - Generally, in Zimbabwe crop production is more suitable for Region 1 and 2, while livestock, specifically cattle ranching and wildlife is practiced in Regions 3, 4 and 5 which receive low rainfall 3. Availability of capital - Farmers with limited capital available to them have limited choices of enterprises they can engage in. - Farmers are left with very little choices as they cannot afford to engage in capital intensive enterprises 4. Availability of market and market price - Farmers feel more secure to engage in the production of a commodity whose market is easily available than those with market which is scarce. - Farmers are generally attracted by high market prices for their products. 5. Availability of labour - Some farmers may decide not to undertake certain enterprises because they require a lot of labour, for example, tobacco at reaping stage. 6. Government policy - Government policy also has some bearing on the farmers’ choices of enterprises. - Availability of subsidies and favourable producer prices may attract farmers into certain production. 7. Farmers’ knowledge and preference - Farmers generally want to engage in enterprises they have knowledge in. - Individual farmers have different preferences and tastes. November 1996 b). state the factors that must be considered before starting an agricultural enterprise. (5) Possible Answer - finance, source/ amount; expense / capital - market; profitability/ viability/ income - purpose of product - labour - transport - skill - land/ soil type; climate; storage/ housing - farmer’s preferences; water Opportunity cost - farmers are faced with the problem of choosing between the many different opportunities they have. For example, in crop production, one may have to choose between maize, sorghum and field bean production. When they choose to grow maize instead of the other crops, the opportunity cost is the money that they would lose from not growing the next best crop among the list 133 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 *opportunity cost is therefore the next best alternative foregone when a choice has to be made* - - another example is when a farmer has resources to produce poultry. The farmer then chooses to produce broilers instead of layers. The opportunity cost is the revenue that the farmer is going to lose out by not producing layer birds the problem of opportunity cost is one that all farmers face every time they make a decision to produce. One cannot carry out all the enterprises considering that resources are limited so farmers need to make wise decisions wherever necessary ********************************************* Demand, supply and price  describe the laws of demand and supply  interpret demand and supply curves and schedules  describe determinants of market price for agricultural commodities Principle of demand - demand is the quantity of a commodity that customers are willing and able to buy at a particular price and time. Demand is mainly influenced by the price of the commodity giving rise to the “Law of demand” Law of demand - law of demand states that “the higher the price of a commodity, the lower the quantity demanded and vice versa” - customers will buy less of a particular commodity when the price of that commodity rises and they buy more when the price goes down - commodity price and the quantity demanded are usually inversely related. An illustration of the law of demand is shown in the demand schedule for tomatoes given below: Demand schedule for tomatoes Price of tomatoes ($/kg) 0.5 1.0 1.5 2.0 2.5 - - Quantity of tomatoes demanded in kg 25 20 15 10 5 from the above schedule, it can be noted that as the price of tomatoes rises from $0.50/kg to $2.50/kg, the quantity of tomatoes demanded decrease from 25kg until it reaches 5kg at $2.50/kg. the deamd schedule above can be presented in the form of a graph to give the demand curve below 134 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Factors influencing demand - in addition to the price, demand of a commodity is also influenced by: 1.Income of consumers 2.Price of substitutes 3.Season 4.Customers’ religion 5.Quality of the commodity 6.Taste and preferences Principle of supply - supply is the quantity of a commodity that producers are willing and able to offer for sale at a particular price and time. Law of supply - law of supply states that the higher the price of a commodity on the market the more the quantity of that commodity the producers are willing to sell - from the supply schedule below, it can be noted that as the price of tomatoes on the market increases so is the quantity producers are willing to offer for sale Supply schedule for tomatoes Price of tomatoes ($/kg) 0.5 1.0 1.5 2.0 2.5 Quantity of tomatoes supplied in kg 5 10 15 20 25 135 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 -using the supply schedule of tomatoes shown above, a supply curve can be drawn as shown below -the supply curve goes upwards from left to right. This shows that there is a positive correlation between price and supply of a commodity. The higher the price of a commodity, the greater the supply. Other factors affecting supply 1.Price of other goods 2.Production costs 3.Weather conditions 4.Technology 5.Pests and diseases 136 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Explain factors which influence the supply of a named product. Name of product: ……………………… Milk / meat/ egg  availability of complimentary products;  demand;  price of product /  similar products/  weather;  disease;  cost of production,  supply of raw materials;  technology;  government policy;  population;  religion;  production cycle; [3] ********************************************* Diminishing returns    explain the law of diminishing returns interpret the law of diminishing returns describe the implications of diminishing returns in agriculture Diminishing returns - the law of diminishing returns states that as the amount of one variable inputs is creased , output also increases but up to a certain point beyond which output begins to decrease . - eg as the amount of fertilizer used in growing maize is increased , the yield of maize also increase . - however as more units of fertilizer are added, a point is reached where each additional unit result are lower than the previous one . - the law of diminishing returns enables the farmer to choose the amount of inputs to use in order to get the best of most economical output. 137 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 ********************************************* Risk and uncertainty    Outline risks and uncertainties that can be encountered in Agriculture distinguish between risks and uncertainties explain ways of minimising the effects of risks and uncertainties Risks and uncertainities - a risk is a danger that can be predicted and insured e.g fire, outbreak of pests, diseases, theft, accidents to employees, floods and drought. - an uncertainty is an unwanted circumstances that cannot be predicted or insured e.g. change in demand, change in government policy, transport reliability tp ferry produce to the market place and technology changes. Ways of reducing /spreading risks  taking an insurance policy: If a loss occurs a claim can be made to the insurance company to pay the farmer for loss.  growing different types of crops (diversification): if some crops fail there is a chance that others may succeed.  having spare equipment e.g a spare tractor will ensure that there are delays in land preparations due to a breakdown.  producing crops on contract i.e. contract farming. In this way the market for produce is guaranteed.  Constructing dams for irrigation during drought.  Choosing an enterprise suited to one”s agro-ecological zone – growing drought tolerant crops in region 3 , 4 and 5.  Maintaining flexibility e.g having storage facilities for crops will enable the farmers to supply on the market when prices are good, the farmer can store and wait for the right time to sell.  Using records – records from previous season help in making good decision. 138 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 N 2015 The following list is made up of risks and uncertainties. Complete the blank spaces using an R for risk and U for uncertainty. (i) Change in government policy _________________U__ (ii) Damage of crops by drought __________________R__ (iii) Theft of cattle by poachers ____________________R_ (iv) Price fluctuation of inputs _____________________U_ ********************************************* Decision making    explain the importance of decision making in agriculture outline the economic factors influencing decision making Outline the steps to follow when making decisions on a farm Opportunity costs. - the correct decision will result in good profit and bad decisions lead to losses. - opportunity cost is defined as the best alternative forgone or lost by the farmer as a result of choosing another. - for example, if a farmer chooses to grow marigold flowers instead of petunia flowers, then the opportunity cost is income he would have earned from petunia flowers. - the principle of opportunity cost is important in that the farmer must make a decision with the least opportunity cost .in other words the value of what you choose should be more than the value of what you have not chosen or foregone. Decision making.  decision making can be defined as the process of making choices among possible alternatives.  a farmer must make decision on:  what to produce  when to produce  how to produce and  for whom to produce  in making decisions, it is important for a farmer to consider :  economic factors – availability of cash for buying inputs and machinery.  climatic factors –suitability of crops or livestock chosen to the conditions in an area e.g temperature and rainfall.  Physical factors-suitability of soil or topography of the land.  Management factors –farmers’ knowledge and experiences of what she /he wants to do and availability of labour.  The farmer’s goals must be clearly defined before a final decision is made.  The decision making process involves a series of steps to be followed: i) Outline the goals and outcome, e.g.  To make profit  To stay in business  To increase the number of customers, and  Expand the farming business ii) Gather data iii) Look for alternatives 139 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 iv) v) vi) vii) Compare alternatives Make the decision Immediately take action to implement Identify strength and weaknesses of the decision and possible future and improvements. State any three factors to consider when making a decision on a farming enterprise. [3]  Farmers knowledge/ experience;  Budget;  Availability of cash; resources; labour;  Market/ demand;  Environment; climate/ weather; land / religion;  Transport reliability;  Farmer’s preference;  Profitability. ********************************************* SUB TOPIC: FARM BUDGETING ********************************************* Budgets     explain the importance of budgeting in farming identify sources of information for budgeting calculate the gross margin for an agricultural enterprise prepare partial and complete budgets FARM BUDGRTING.  a budget is an estimate of expected income and expenditure of an enterprise on a farm.  when the budget for the different enterprises are added up a whole farm budget is produced. Partial budget  It is an estimate of expected financial gains and losses when there is a small change in production system.  If expected gains are more than losses, then the change will be worthwhile.  A partial budget is required under the following circumstances:  When replacing manual labour with machinery such as combine harvester,  Substituting broiler mashes with homemade mixes,  When reducing the hectarage of one crop and increasing it by the same amount for another. Importance of budgeting Explain the importance of preparing budgets in farming. [3]  Farm budgeting enables farmers to: Helps farmers to secure loans; 140 GWANZURA.R. guide 2020-0773266377 / 0717 558 917          Determines expected profits; Determines financial requirements Enable comparisons Helps in decision making; Helps in resource allocation; Get loans from banks Calculate expected profits and losses Direct operations of the farm /enterprise Enable a farmer to find out the best ways of reducing production costs Sources of information for budgeting  Information used to produce a budget must be factual and therefore it should come from reliable sources these include:  Agritex officials  Farmers records  Supplies of inputs  Banks  Experienced farmers in the area  Farmers organizations  Educational institution such as Agricultural Colleges and Universities Farm records and accounts.  Farm record are daily recordings of events /activities at the farm. Types of farm records.  There are two main types of records kept by a farmer. a) Physical or production records.  They include records of all activities except finance .eg quantities of maize, harvested, fertilizers, harvested, fertilizers used, planting dates, harvesting dates, planting dates, spraying dates, stock register, inventory, mortality rates, breeds kept, weaning dates, fertilizer application date etc. Financial records  These are records of income and expenditure on the farm.  e.g budgets, profits and loss accounts, water bills, telephone bills, cash books journal and ledger. advantages of keeping records.  keeping records enable the farmer to:  get loan from banks  detect theft more easily  plant crops at the right time  choose enterprise  calculate profit /loss  avoid unnecessary expenditure  make realistic plans  calculate value of production  estimate the value of the farm  detect mistakes which can be avoided in future 141 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Profit and Loss account.  A profit is made when income from an enterprise is more than expenditure.  A loss is made when income from an enterprise is less than expenditure.  A farmer has to spend money on the materials required for production to take place.  These include inputs like seeds, fertilizer and stock feeds. Money used to buy them is called expenditure.  After harvesting produce, the farmer sells it to the market, the money received from selling the produce is called income.  If total is equal to total expenditure then the farm is break even (i.e .there is no loss or no profit) . Farming costs. With reference to the production of a cereal crop, explain the difference between fixed costs and variable costs. Give an example in each case. [3+3] a) Variable costs (VC).  These are costs which are allocated to a particular enterprise.  The costs vary according to the size of the business, eg broiler starter mash costs to the broiler enterprise.  Variable costs rise as cost of production increases and fall as production decreases. b) Fixed costs (FC).  These are costs which cannot be allocated to a particular enterprise but are allocated to the whole farm e.g. costs of rent, electricity, farm license, advertising and insurance .  Generally fixed costs do not change from season to season/ do not change with scale of production N2012 The schedule below shows the layout of the farmer’s diary for the month of September 2005. DATE ACTIVITY 11.09.05 Bought 10 bags of maize seed at $ 500 each. 11.09.05 Paid $ 400 for farm rates. 15.09.05 Bought chemical for dipping for $400. 18.09.05 Hired a tractor to plough for $500. 20.09.05 Paid $400 insurance for the farm. 24.09.05 Purchased 2 sows for breeding for $500. 28.09.05 Hired equipment for fencing for $ 200. (i) Calculate the farmer’s total variable costs for September 2005. [2] Maize seed 10 x 500 Dipping chemical Tractor hiring Sows Fencing Total variable costs $ 5 000 $ 400 $ 500 $ 500 $ 200 $ 6 600 142 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 (ii) State the importance of the information in b (i). [2]  Enable the farmer to calculate Gross margins of enterprises;  To be able to assess the viability of the farm; Farming returns. a) Gross income. (GI)  The total amount of money received after selling a product (total yield x price).  GI is also referred to as gross output.  b) Gross margin (GM). It is the gross income less variable costs i.e GM=GI-VC N2002 The following are expenses which were incurred by a farmer who grow 4 hectares of maize: Fertilizer $10 000.00 Pesticides $ 1 000.00 Seed $ 2 000.00 Transport $ 1 000.00 Hired labour $ 2 400.00 The farmer harvested 8 tonnes of maize from the 4 hectares and sold all to the grain marketing board at $ 6 000.00 per tonne. Calculate the gross margin per hectare? Show all working. Total variable costs = $10 000.00 $ 1 000.00 $ 2 000.00 $ 1 000.00 $ 2 400.00 $16 400.00 Total Variable costs / ha = $ 16 400.00/8 = $ 4 100.00 Gross income. (GI) = total yield x price =8 x $ 6 000.00 = $ 48 000.00 Gross income. (GI)/ ha = $ 48 000.00/ 8 = $ 12 000.00 GM = GI - VC 143 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 = =  $ 12 000.00 - $ 4 100.00 $ 7 900.00 c) Farm gross margin. Sum of gross margin from all the enterprises on the farm i.e FGM=GM d) Net farm profit (NFP) farm gross margin – less fixed costs i.e. NPF =FGM-FC N2003 A farmer produced 5 tonnes of maize during the 2001 to 2002 season. G.M.B producer price for maize was $ 16 000/ tonne. The total cost of inputs on maize project was $ 50 000. A broiler enterprise gave the farmer a return of $ 150 000 after spending $ 80 000. The farmer also spent $ 25 000 on rentals, $ 20 000 on tractor repairs and $ 11 000 on insurance. (i) Calculate the total value of production for the season. [1] Maize Broilers Total (ii) = 5 x $ 16 000 = $ 80 000 = $ 150 000 = $ 150 000 + $ 80 000 = $ 230 000 Calculate the gross margins for maize and broiler enterprises. [1+1] Gross margin (maize) Gross margin (broilers) (iii) = $ 80 000 - $ 50 000 = $ 30 000 = $ 150 000 - $ 80 000 = $ 70 000 What is the total gross margin for the farm? [1] Total Gross Margin = Maize + Broilers = $ 30 000 + $ 70 000 = $ 100 000 (iv) Work out the farmer’s profit / loss. [1] Farm profit = $ 100 000 - $ 56 000 = $ 44 000 ********************************************* SUB TOPIC: AGRICULTURAL MARKETING ********************************************* Functions and factors of marketing  explain the functions of marketing in agriculture  state factors affecting marketing of agricultural produce 144 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 MARKETING  A market is a place where buyers and sellers meet, or a place where buying and selling take place.  It is not always physical location but buyers and sellers should interact.  Marketing is the process of disposing of goods at various prices at given time and place. FUNCTIONS OF MARKERTING.  Financing: finance is required to meet costs such as advertising, loans from banks  Risk bearing: the level of risk bearing depends on the time to produce leaves the farm up to it is sold. Produce may deteriorate in quality, may be damaged by fire and may take a long time to be sold.  Transporting: the produce must be transported timeously and the farmer must meet the costs. Agricultural products are bulky and therefore transport costs are usually high.  Storing: storing helps the farmer to supply on the market when prices are high. Storage of produce has a cost, especially refrigerated storage.  Assembling: produce from many small producers may need to be delivered at a central point from which it can be transported in bulk at lower costs .  Standardising and grading: this involves fixing permanent grades of produce and grading involves grouping uniform products.  Packaging: it involves putting some products into some forms of containers for easy handling , identification ,advertising ant to protect product from getting dirty.  Selling; it involves a study of the market demand and allocation of products to satisfy different market ********************************************* Marketing legislation  explain the marketing legislation for agricultural produce and commodities Identifying crop and animal products that are controlled by marketing legislation in Zimbabwe Controlled and uncontrolled marketing Controlled marketing    It is when sellers are forced by the law sell their produce to specific buyers . In Zimbabwe the Grain Marketing Board (GMB) is a typical example ,usually the price for the produce is decided by the Government . The buyer usually prescribes the market acceptance standards for the product which also influence the grade. Uncontrolled marketing  It is the selling of produce to any consumers without any intervention from the Government. 145 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  The prices in uncontrolled marketing are determined by market forces and generally negotiable. Marketing of major crops and livestock in Zimbabwe  there are a number of organizations involved in the marketing of agricultural produce in Zimbabwe.  these organizations are assisting in the orderly marketing of specific crops.  others engage farmers in contract farming and some give inputs packages to the farmers.  the GMB buys crops such as wheat, maize, soya beans, sunflower and ground nut from farmers.  the GMB in turn sells these products locally or export them if there is enough strategic reserves in place.  The Tobacco is through farmers (TIMB) compels all tobacco farmers to register with the board in order to sell their tobacco.  Sale of tobacco is through auction at tobacco auction floors operated by private companies.  Other companies include Dairiboard Zimbabwe Limited (DZL), Cold storage Company of Zimbabwe (CSC) and Colcom.  The marketing of agricultural products is regulated by the Agricultural Marketing Authority of Zimbabwe. Its functions are to promote:  Production of strategic crops(tobacco), cotton, sugar, soya beans, barley;  Crop production for provision of food security (maize, wheat, sorghum);  Livestock production (beef, dairy, piggery, poultry, small stock);  Borrowing and lending agricultural products.  Contract farming through encouraging private sector participation;  Marketing and fair pricing of agricultural commodities  Provision of advice to the Minister of Agriculture on formulation of national policies and;  Coordination of operations of statutory boards charged with regulating and marketing of agricultural products. Agricultural co-operatives  A co-operative is a registered group of people who work together to achieve a common goal. Advantages of agricultural co-operatives       Low costs are incurred due to discounts on bulk transportation of inputs and produce Sharing of ideas amongst members helps to improve production efficiency and increase profits Access to loans for buying inputs is increased because some organisations have funds set aside for community projects Fixed costs are shared and this increases net income Members have bigger bargaining power than individuals Working together promotes friendship amongst members on the community 146 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Types of co-operatives Production co-operatives /farming co-operatives  Members grow crops or rear livestock together. Buying co-operatives  Members sell inputs and implement to fellow members at reduced priced due to discount on bulk buying. Marketing co-operatives  Members sell produce as a group and benefit from discounts on bulk transportation. Banking /saving c0o-operatives  Members save money together in banks, earning interest and also avail loans to each other. Principles of co-operatives Open membership  All members of the community are free to join and their conduct should be guided by the constitution Democracy  All members have equal voting rights and majority decisions are binding Shares n dividends   All members buy and own shares They also get dividends according to the number of shares owned Joining and leaving  no person is forced to become a member and members are free to leave as per constitution Education   members must get some training on management of the co-operative such as accounting this is necessary to ensure the co-operative is run professionally problems faced by co-operatives dishonesty   some members misinform others in order to get more benefits than others others do not pay back money loaned to them mismanagement 147 GWANZURA.R. guide 2020-0773266377 / 0717 558 917  inadequate trained leaders embezzle funds or get involved in illegal deals using co-operatives lack of capital    inadequate funded activities usually fail. members get disheartened by the hardships and leave. there is need for low interest loans to be set aside for co-operatives lack of transport   most agricultural products are highly perishable and bulky many co-operatives do not have access transport which is affordable and reliable. ******************************************* 148 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 AGRICULTURE (4001) CONTINUOUS ASSESSMENT FORM 3 TERM 3 PROJECT TEACHER’S TASK GUIDE Learners should choose a project topic from any topic in the Form 3 Agriculture (4001) National syllabus. The project can be a survey or experimental in nature. Topic/problem S - specific M - measurable A - attainable R - realistic T - time frame Objectives There should be three with the following characteristics: specific, measurable, attainable, realistic and time framed and well sequenced in chronological order. Introduction Background in relation to the topic. Accept future/past tense. It should answer where (place), when (time), what (explanation of topic), how to be done and why (reason/reasons). Literature review This looks at literature that is related to the topic under study. Learners can quote relevant literature throughout the project. 4001/CA/2017/PROJECT 149 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Methodology/Experimental Design The learner should address the following:  How objectives are to be achieved.  Explanations of treatments – visits and interview schedules.  For surveys – use of questionnaires, recording of dates, instruments, explanations to improve authenticity. NB: Methodology should be objective based. Data Collection Collected data should be relevant, orderly and consistent. Include dates (consistent) figures, observations should be well explained, table of results and observations should be objective based. This is the core of the project. Data analysis/interpretations Use charts/graphs/histograms – comments on data presented. All the explanations should be scientific and matched to textbooks. This should be objective based. Summary/conclusion This should be related to the objectives, should answer the objective. Indicate the successes or failures and any closing remarks. Recommendations Make recommendations related to findings of the project that is topic and reasons why. Acknowledgements Give a vote of thanks to people who assisted indicating area of assistance. 4001/CA/2017/PROJECT [Turn over 150 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 Reference/bibliography List of books consulted, magazines, internet. Title Year Author(s)/initial(s) Publisher 151 GWANZURA.R. guide 2020-0773266377 / 0717 558 917 MARKING CRITERIA Area Marking Point 1 TOPIC/PROBLEM 2 OBJECTIVES 3 INTRODUCTION/ BACKGROUND METHODOLOGY/APPROACH/ EXPERIMENTAL DESIGN Topic to be specific, measureable, attainable realistic and timeframed. Three objectives: Specific, measurable, attainable, timeframed, realistic. Should summarise: Where, when, what, how and why. How is it to be done? Diagrams, graphs, measurements, explanations, visits and interviews. Use of questionnaires, recording of data. Instruments, explanations (Authenticity). Dates, figures. Tables of results and observations, reference to objectives set. (This is the core of the project). Use of language. Data collected. 4 5 DATA COLLECTION 6 EVIDENCE OF PRACTICAL WORK PRESENTATION OF REPORT/LAYOUT ILLUSTRATION OF REPORT/LAYOUT & SAMPLES DATA ANALYSIS/ INTERPRETATION SUMMARY/CONCLUSION 7 8 9 10 11 12 13 RECOMMENDATIONS ACKNOWLEDGEMENTS REFERENCE/BIBLIOGRAPHY Marks Awarded 5 10 10 10 21 4 Logic/sequence, neatness. 5 Relevant material Quality. Charts/graphs/histograms/comments. Refer to objectives. • Related to objectives • Answers objectives 5 Failures explained Comments related to project findings. Vote of thanks to people who assisted. List of books consulted Authors and Publishers. TOTAL 15 5 5 3 2 100 NOTE: Place/stick the scheme at the back of each project book. 152 GWANZURA.R. guide 2020-0773266377 / 0717 558 917

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