Evaluation of Thuringiensin for Control of Heterodera glycines on Soybean.

The efficacy of ABG-6162A (1.5 L formulation of thuringiensin) for control of Heterodera glycines on soybean (Glycine max cv. Williams 82) was evaluated in the greenhouse at rates of 0, 10, 100, 500, and 1,000 ppm a.i. and in a field experiment at rates of 0, 3.4, 10.2, and 20.3 g a.i./100 m of row applied in an 18-cm-wide band. In the greenhouse, the 100-ppm rate was as effective as an equivalent rate of aldicarb and caused no phytotoxicity, but the higher rates of thuringiensin were highly phytotoxic. In the field experiment, numbers of females recovered from plots treated with thuringiensin at the 3.4-g and 10.2-g rates were greater (P </=0.05) than from plots treated with aldicarb at 20.3 g a.i./100 m of row in an 18-cm-wide band or from the H. glycines-resistant soybean cv. Fayette. Yield of the untreated Williams 82 control differed significantly only from the 10.2-g rate of thuringiensin, but yield of untreated Fayette was greater than that from any of the treatments involving Williams 82.