Cabbage Integrated Pest Management : An Ecological Guide.

Major Agronomic PracticesThe use of ditch and furrow irrigation is usually preferred to overhead irrigation. Ditches also ensure rapiddrainage of excess soil moisture during the rainy season.Other useful water management practices to help keeping foliage dry to prevent spread of water-bornepathogens include:lllllplanting in wide rows to increase air flow between rows.orienting rows towards prevailing wind.planting with wide spacing in the rows.irrigating early enough to give plants a chance to dry during the day.working with plants only when leaves are dry.Related exercises from CABI Bioscience/FAO manual:2-C.8. Flooding and overhead irrigation3.10 Intercropping and trap crops3.10.1 Intercropping and barrier cropsIntercropping is the simultaneous cultivation of two or more crops in one field. It can also be called mixedcropping or polyculture. When plants of different families are planted together it is more difficult for insectpests and diseases to spread from one plant to the next. Insects have more difficulty in finding hostplants when they are camouflaged between other plants. Fungus spores may land on non-host plantswhere they are lost. Natural enemies of insect pests get a chance to hide in the other crop. When theintercrop is taller than the cabbage plants they can form a “barrier” thus reducing spread of insect pestsand diseases.Certain intercropped plants excrete chemicals or odors which repel insect pests of other plants. Examplesare onion and garlic. The strong smell repels some insects, and they fly away and will not attack otherplants growing between the onion or garlic plants. Intercropped cabbage with tomatoes is reported toreduce diamondback moth (Plutella xylostella) infestation. See box below.Intercropping for diamondback moth control?In both Indonesia and Malaysia, it was found that the population ofdiamondback moth (DBM) on cabbage was less in cabbage-tomatointercropped plantings than in fields with cabbage alone. Also, parasitism ratesof DBM larvae were higher in the intercropped field. JSimilar results were found in Sri Lanka but in Singapore it didn’t work so well. (In: Sivanaser, 1991).Because the results vary from location to location it might be worth trying if this cropping systemwould be practically useful in your area. See box below.Other plants may have nematicidal activity, killing nematodes in the soil. An example is sesame: rootextracts caused mortality of nematodes in laboratory tests . Another “famous” nematode-killer is theflower Tagetes sp. which can be effectively controlling nematodes on tomato (Tumwine, 1999).Intercrops could also reduce the risk of crop failure by providing an alternative crop and additional incometo a farmer.Cabbage Ecological Guide - 200046