Almond growers reduce pesticide use in Merced County field trials

Organophosphates have been widely used by California almond growers, although they negatively impact beneficial insects, and have been found in the winter fog and agricultural runoff reaching the rivers of the San Joaquin Valley. Spring and summer applications are fatal to beneficial arthropods and insects. This six-year study of nut growers examined the use of biological controls in lieu of insecticide sprays. Data were collected on the navel orangeworm, peach twig borer, spider mites, San Jose scale, beneficial insects, earthworms, and soil characteristics. The whole-farm comparison found success with good sanitation practices, cover cropping, careful monitoring of pests, using Bt applications at bloom, controlling scale and mite eggs with oil dormant sprays, primpt harvests, and introduction of the navel orangeworm.