Response of Soybean Cultivars to Aldicarb in Heterodera glycines-infested Soils in Missouri.

Soybean cultivars in maturity groups III, IV, and V that were resistant or susceptible to Heterodera glycines were evaluated for their response to in-furrow applications (5.43 kg a.i./ha) of aldicarb. Tests were conducted over three years (1988-1990) in various H. glycines-infested locations in Missouri for a total of 16 environments. In 7 environments, overall yields were higher (P </= 0.05) in aldicarb-treated than in nontreated plots. In one environment, soybean yields in aldicarb-treated plots were lower (P </= 0.05) than in nontreated plots. Cultivar x aldicarb interactions were detected in only one environment. Resistant cultivars yielded higher than susceptible cultivars in 13 of 15 environments. Final populations (Pf) of H. glycines were generally unaffected by aldicarb treatment; however, in 3 environments Pf were significantly higher, whereas in 2 other environments Pf were significantly lower in aldicarb-treated plots than in nontreated plots.