On-farm comparisons between bio-insecticides and synthetic insecticides in vegetable production

摘要

On-farm comparisons of bio-insecticide and synthetic insecticide use in chaisim (Brassica pekinensis) production were made in vegetable agroecosystems in Bangriang sub-district, Songkhla, Thailand. in November-December 1999. Chaisim was planted in two experimental sites by two different farmers, Bio-insecticides (the bacterium Bacillus thuringiensis and the nematode Steinernema carpocapsae) and synthetic insecticides (cypermethrin, profenofos, and chlorfenapyr) were applied using a randomised complete block design, with three treatments and two replications. The occurrence of insects (flea beetles and Lepidopterous larvae) was monitored every four days after crop germination. The results suggested that synthetic insecticide is potentially more effective than bio-insecticide. There were no significant differences on vegetable yields among the treatments, but use of synthetic insecticides achieved a higher net income than bio-insecticides because of tile higher cost of nematode application. This is a preliminary result which must be verified by controlled experimentation.