Cprt 22 Module 3.2

tried and true” control technique

Crop rotation brings economical and important in the control of many plant pathogens such as

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

crop rotation for sweet potato weevil

crop rotation for bacterial wilt population in the soil

can kill pests through mechanical injury, starvation (via debris destruction) desiccation and exposure

Plowing under crop debris and weeds after each cropping season will:

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.

Sclerotium, Rhizoctonia, Pythium, and Phytophthora causes

raised bed

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

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)

trap crop for watermelon, cantaloupe and cucumber

planting marigold (trap crop) in a row at the center of rows of tomato (main crop) to attract thrips early and destroyed

Planting trap crops in a strip along one common border between two or more crops.

he trap crop planted in a strip in between corn and cotton for the control of green stink bugs.

strip trap cropping of sorghum traps what

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

are antagonistic to plant pathogens because they release substances in the soil that are toxic

occurs when chemicals released from the plants reduce the population of a pest organism

controls Meloidogyna hapla or M. incognita

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

the use of Tissue cultured of meristem tips produce disease-free planting materials is utilized in what plants

• 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.

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

A neutral pH is favorable for the crop. • Soil pH has an effect on the decline or increase in the population of specific pests

soils with higher pH due to high _____ content there is increased incidence and severity of root rot on peach

root rot on peach

Clubroot of crucifers

Plasmodiophora brassicae pH scales

increased early blight in potato caused by Alternaria solani (MacKenzie, 1981), fusarium wilt of melon caused by Fusarium oxysporum

blight in potato caused

fusarium wilt of melon caused by

• 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.

fire blight on apple

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

source of N favors take all of wheat disease and potato scab

reduces severity of take-all disease of wheat (Brennan, 1989) and potato scab (Streptomyces scabies)

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).

white tip of rice

decreases disease severity of early blight of tomato

generally increases disease resistance through plant defense responses

increases resistance to stem nematode

decrease fusarium wilt incidence

(Ditylenchis dipsaci)

reduce take all disease of wheat (Bockus and Tisserat, 2005) • increases Phytopththora cinnamomi on avocado (Huber and Wilhelm, 1988).

manganese increases this disease on avocado

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.

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

Overlapping roots of trees (if closely spaced during planting) favor

• 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.

Immediate removal of crop residues and removal of weeds that serves as alternate hosts minimize the occurrence of pests.

• 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

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

irrigation systems that are highly effective in controlling disease

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.

drainage canal reduces what disease

used to control Fusarium wilt of banana and Verticillium wilt of cotton.

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,

usually practiced in arid regions • aimed to reduce soil-borne pathogens and nematode control

• refers to organic matter incorporated into the soil to improve its physical properties, such as water retention, permeability, water infiltration, drainage, aeration and structure.

• a layer of material applied to the surface of soil

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.

used to limit disease risk, but may be impractical or uneconomical.