Crop rotation
tried and true” control technique
nematodes, bacteria and fungi
Crop rotation brings economical and important in the control of many plant pathogens such as
potato, tomato, eggplant and pepper
not avisable to rotate crops of the same family as the rotated crops may still serve as host to the pest. For example, rotating crops that are members of solanacea such as
sweet potato with squash and corn
crop rotation for sweet potato weevil
tomato with corn, string bean and pechay
crop rotation for bacterial wilt population in the soil
Soil cultivation
can kill pests through mechanical injury, starvation (via debris destruction) desiccation and exposure
kill pests and pathogen propagule, b) reduce initial insect population or pathogen inoculum for the next cropping season, and c) destroy wild vegetation (weeds) and volunteer crop plants in and around crop-production habitats.
Plowing under crop debris and weeds after each cropping season will:
Shaping the topsoil and earthing up or hilling up (Raised beds or plots)
keep the soil dry that is in direct contact with the root collar of the plant or may come into contact with a low hanging fruit which is subject to infection by soil-borne fungi or bacteria.
damping off seedlings, basal stem rot and wilts
Sclerotium, Rhizoctonia, Pythium, and Phytophthora causes
Sclerotium, Rhizoctonia, Pythium, and Phytophthora
raised bed
Trap cropping
nvolves the planting of an attractive small early crop (trap crop) to protect the main crop. The trap crop may or may not be harvestable
Perimeter trap cropping
Trap crop surrounds the main crop from all sides (Fig. 15) Feasible on small to medium scale areas (too resource-intensive on large scale (seed, time, management)
Squash
trap crop for watermelon, cantaloupe and cucumber
Row trap cropping
planting marigold (trap crop) in a row at the center of rows of tomato (main crop) to attract thrips early and destroyed
Strip trap cropping
Planting trap crops in a strip along one common border between two or more crops.
Sorghum
he trap crop planted in a strip in between corn and cotton for the control of green stink bugs.
Green stink bugs
strip trap cropping of sorghum traps what
Dead-end trap cropping
Diamondback moths are attracted to yellow rocket over cabbage, trick is: • Trap crop planted in higher densities to capture more eggs of the insect pest and destroyed • Trap crop planted earlier than main crop
Tagetes erecta
are antagonistic to plant pathogens because they release substances in the soil that are toxic
Antagonism
occurs when chemicals released from the plants reduce the population of a pest organism
Crotalaria incana or C. mucronata
controls Meloidogyna hapla or M. incognita
Use of healthy planting materials
The use of healthy planting materials, healthy seeds and certified seeds is an essential component of cultural control of pests. • Cuttings, stocks, scion, buds, bulbs, tubers, corms and other vegetative planting materials should come from healthy plants
Bananas and abaca
the use of Tissue cultured of meristem tips produce disease-free planting materials is utilized in what plants
Habitat diversification
• practice of growing two or more crops simultaneously in a single field such as multiple cropping, intercropping, multi-storey cropping and companion planting. In so doing, the habitat of pests are diversified or manipulated.
Multi-storey cropping
coconut-based farming systems with perennials. The ecological conditions to which coconut is adapted are also suitable for growing a variety of fruit and plantation crops, fruits and vegetables underneath
Soil pH and crop nutrition management
A neutral pH is favorable for the crop. • Soil pH has an effect on the decline or increase in the population of specific pests
CaCO3
soils with higher pH due to high _____ content there is increased incidence and severity of root rot on peach
Phymatotrichopsis omnivora
root rot on peach
Plasmodiophora brassicae
Clubroot of crucifers
5.7 hghly virulent, midly 6.2, gone by 7.8
Plasmodiophora brassicae pH scales
Under-fertilization of Nitrogen
increased early blight in potato caused by Alternaria solani (MacKenzie, 1981), fusarium wilt of melon caused by Fusarium oxysporum
Alternaria solani
blight in potato caused
Fusarium oxysporum
fusarium wilt of melon caused by
Over-fertilization of Nitrogen
• increase disease susceptibility to fire blight on apple (Erwinia amylova) and pear (Johnson, 2000). • In the case of rice diseases, increased susceptibility to bacterial blight, rice blast and sheath blight.
Erwinia amylova
fire blight on apple
Ammonium
form of nitrogen when used to fertilize crucifers makes these plants more susceptible to club root and Fusarium root rot as these pathogens are acid loving
Nitrate
source of N favors take all of wheat disease and potato scab
Phosphorus
reduces severity of take-all disease of wheat (Brennan, 1989) and potato scab (Streptomyces scabies)
Potassium
reduces drought stress but may affect pathogen establishment (Wang et al., 2013). • It delays maturity/senescence in some crops and increases vulnerability to facultative pathogens (Hendrix and Cambell, 1973), increases root knot (Meloidogyne incognita) (Marks and Sayre, 1964) and white tip of rice (Aphelenchoides oryzae) (Datnoff, 1994). • decreases disease severity of early blight of tomato (Blachinski et al., 1986).
Aphelenchoides oryzae
white tip of rice
Potassium
decreases disease severity of early blight of tomato
Calcium
generally increases disease resistance through plant defense responses
increases resistance to stem nematode
decrease fusarium wilt incidence
Stem nematode
(Ditylenchis dipsaci)
Manganese
reduce take all disease of wheat (Bockus and Tisserat, 2005) • increases Phytopththora cinnamomi on avocado (Huber and Wilhelm, 1988).
Phytophthora cinnamomi
manganese increases this disease on avocado
Zinc
reduce citrus greening or “huanglongbing” disease (HLB; Fig. 34) severity in infected citrus (Iftilkhar et al., 2016) together with pruning, vector control and fertilization with ZnSO4 + MnSO4 foliar application for under 2 months.
Dense canopy leads to high relative humidity
which is favorable to most fungi and bacteria. Example: pruning after harvest is recommended to mango trees after harvest thereby reducing the amount of anthracnose disease in the next cropping season
Root to root transfer of soil borne pathogen
Overlapping roots of trees (if closely spaced during planting) favor
Proper plant spacing and density
• Canopy management by pruning, thinning, or regulation of dense of crop stand by controlling the number of seeds per hill when sowing/planting has an effect on insect pest numbers, disease severity by influencing the environment or microclimate.
Sanitation and clean culture
Immediate removal of crop residues and removal of weeds that serves as alternate hosts minimize the occurrence of pests.
Burying deep
• Burying deep into the soil the crop debris after harvest will deprive insect pests, weed seeds and aerobic pathogens of O2 and • favors the population of anaerobic decomposers and antagonistic microorganisms that compete and or antagonize the pathogenic ones
Water management: Irrigation techniques/drainage canals
the practice of managing water and using irrigation techniques that will reduce pest population is definitely a cultural control method. The type of irrigation is very important in terms of disease risks
trickle or drip irrigation and sub-soil irrigation
irrigation systems that are highly effective in controlling disease
Drainage canals
construction in orchards and gardens is a good cultural management strategy to control water-loving pathogens like Phytophthora spp. in fruit trees. This needs to be done especially in areas where heavy rains and flooding are prevalent.
Phytophthora spp.
drainage canal reduces what disease
Flood fallowing
used to control Fusarium wilt of banana and Verticillium wilt of cotton.
Wet fallowing
leaving the land free from crops while irrigating it intermittently. the bacterial wilt pathogen. • found effective in reducing soil-borne pathogens such as Pythium sp. and Sclerotium sp. that cause damping off disease, and Ralstonia solanacearum,
Dry fallowing
usually practiced in arid regions • aimed to reduce soil-borne pathogens and nematode control
Soil ammendments
• refers to organic matter incorporated into the soil to improve its physical properties, such as water retention, permeability, water infiltration, drainage, aeration and structure.
Soil mulch
• a layer of material applied to the surface of soil
Synchronous planting
when a group of farmers together in a given area plant the same crop at the same time in a certain cropping season that is synchronous planting
less favorable for build-up of pest populations because there is a period where no host plants are available to support the population of the pests. In a continuous cropping, host plants are always available to support population growth of pests.
Surface irrigation
used to limit disease risk, but may be impractical or uneconomical.