Systemic Insecticide Applications at Planting and First Square in Bt Cotton for Early Season Insect Control - La Paz and Mohave Counties

摘要

Temik 15G (6 lbs/acre) and Thimet 20G (7.5 lbs/acre) granular insecticides were applied in furrow at planting and compared to an untreated check in two experiments in Parker Valley and Mohave Valley, AZ. At first square each of these main plots was split in half and either Temik 15G or DiSyston 8L was sidedressed to each subplot and compared to an untreated strip. Thrips and lygus counts were taken at weekly or biweekly intervals and plant response measured from the 2 or 3 leaf stage through layby. Under the thrips pressure experienced in these two experiments (0.5-1.5/plant), Temik and Thimet at planting provided similar and adequate protection from thrips for up to 7 weeks following application. Temik 15G sidressed at 14 lbs/acre at first square provided lygus bug control for up to 42 days following application under light lygus bug pressure (5-15/100 sweeps). Di- Syston 8L sidedressed at 1 qt/acre at first square provided lygus bug control for 35 days following application under moderate lygus bug pressure (15-20/100 sweeps). Under the conditions of this study, systemic insecticide applications at planting and first square did not increase cotton lint yields of insecticide treated Bt cotton plots, compared to the untreated control plots.