Cabbage Integrated Pest Management : An Ecological Guide.

Major Agronomic PracticesLeft-overs from a previous crop should be carefully removed and destroyed as it may still contain diseasesand pests which can spread into the new crop. These left-overs can be used for composting which, ifproperly done, will kill pathogens.When drainage of the field is problematic, or when crops are grown during the rainy season, it isrecommended to prepare raised beds for growing the crop and dig trenches between the beds for drainage.This is also a good practice when problems with soil-borne diseases can be expected: mostpathogens need water to spread and if there is an excess of water all the time, they can easily spread inthe field. Excess water in the soil, or even water-logging, results in weak plants which are more susceptibleto diseases and pests and give a lower yield.Conservation TillageIn conservation tillage, crops are grown with minimal cultivation of the soil. When the amount oftillage is reduced, the stubble or plant residues are not completely incorporated, and most or allremain on top of the soil rather than being plowed into the soil or removed. The new crop is plantedinto this stubble or small strips of tilled soil. Weeds are controlled with cover crops or herbicidesrather than by cultivation. Fertilizer and lime (if necessary) are either incorporated earlier in theproduction cycle or placed on top of the soil at planting. Because of this increased dependence onherbicides for weed control and to kill the previous crop, the inclusion of conservation tillage as a“sustainable” practice could be questioned. However, farmers and researchers are working on lessherbicide-dependent modifications of conservation tillage practices. In general, the greatest advantagesof reduced tillage are realized on soils prone to erosion and drought.(Peet, www4)Advantages• Crops use water more efficiently• Water-holding capacity of soil increases• Water losses from runoff and evaporationare reduced• Soil organic matter and population ofbeneficial micro-organisms aremaintained• Soil and nutrients are less likely to be lostfrom the field• Less time and labor is required to preparefield for plantingDisadvantages• Compaction of the soil may occur• Flooding or poor drainage may occur• Delays in planting when field is too wet ortoo cold• Carryover of diseases and pests in cropresidue• Transplanting in stubble is more difficultand may take longer resulting in delayedor less uniform crop maturity3.8.2 TransplantingCabbage transplants are usually about 4 - 6 weeks old and have 4 to 6 true leaveswhen set into the field. Thoroughly water plants 12 to 14 hours before transplantingto the field. Plants should be dug or cut loose from the soil when being transplanted;ensure the roots are not damaged and exposed to sun or drying wind.Some nurseries harden seedlings before they are sold for transplanting. Seedlingsare hardened by withholding water and nutrients for a certain period of time. Thisresults in seedlings that can survive adverse conditions and are therefore more likelyto recover quickly from the transplanting “shock”.Cabbage Ecological Guide - 200042