Complementary Actions of Low Rates of Bacillus thuringiensis and Chlordimeform Hydrochloride for Control of Caterpillars on Cole Crops

Abstract

Spray mixtures of Dipel® ( Bacillus thuringiensis var. alesti Berliner) and chlordimeform hydrochloride provided effective protection vs. the cabbage looper, Trichoplusia ni (Hubner), and imported cabbageworm, Pieris rapae (L.), at rates as low as 1/16 lb/acre per application of each ingredient. Neither ingredient alone was efficacious at the low rates tested, but factorial analyses of the data on plant injury indicated synergistic effects. The efficacy of the mixture of the 2 ingredients was attributed to efficient complementary effects on plant protection.