ABSTRACT

The degradation of aldicarb (Temik 15G) was examined in the greenhouse and field using soil from four cotton fields with a history of aldicarb use. In the greenhouse, soils were sterilized by autoclaving or not autoclaved (natural) and aldicarb was added at 5lb/A or no aldicarb was added. Rotylenchulus reniformis was incorporated back into the autoclaved soil treatments to return the autoclaved soil to the original natural soil populations. The addition of aldicarb at 5 lb/A to natural soil decreased R. reniformis numbers only 36% compared to 95% in the same soils which were autoclaved. Autoclaving the soils restored aldicarb toxicity. The use of increasing rates of aldicarb did not increase the efficacy of aldicarb in the natural soils. Bacterial populations were increased in the natural soils with aldicarb compared to the soils without aldicarb. However, no bacterial species were consistently associated with aldicarb degradation. The degradation of aldicarb to aldicarb sulfoxide and then to aldicarb sulfone was determined using HPLC. Complete degradation of aldicarb occurred within 12 day after planting the MS and LM field soils. Complete degradation did not occur within 43 day after planting in the CL field.