A critical analysis of organic vegetable crop protection in the U.K.

Abstract

Fifty-five organic vegetable growers in the U.K. were interviewed in 1987 to determine their perceptions of pest problems - insects, diseases, weeds, etc. - and how they deal with them. Over half the growers interviewed thought they lose > 10% of their revenue to pests, an amount the majority feel they cannot afford to lose. Growers perceive their most serious pest problems to be weeds, in particular chickweed ( Stellaria media), couch grass ( Elymus repens) and thistles ( Cirsium spp.). Slugs and birds are the next most important pests, and carrot fly ( Psila rosae) and potato blight ( Phytophtora infestans) the most important insect and disease pests. Avoidance is the main way in which growers attempt to deal with these pest problems, including stopping or not even starting to grow those crops most troubled by pests, by rotations, timely planting and harvesting, transplanting, and avoiding high pest areas on the farm. Although over half the growers use some form of curative control, such as derris, pyrethrum and Bacillus thuringiensis, the majority thought they were ineffective and uneconomic. While there is the possibility of new control practices being developed in the future, the opportunities for more widespread and effective use of existing practices appears to be limited.