Abstract
Levene, B.C., M.D.K. Owen, and G.L. Tylka. 1998. Response of soybean cyst nematodes and soybeans to post herbicides. Weed Science
The effect of herbicides applied to V3 soybeans on race 3 soybean cyst nematode (SCN) reproduction and glyceollin production in roots was measured. Soybeans were treated POST with 1X and 2X rates of herbicides plus adjuvants or with adjuvants alone, and SCN development was measured. Acifluorfen, bentazon, lactofen, COC and NIS applications reduced SCN egg population densities by 50 to 60% compared with the untreated control at four and eight weeks after application. SCN reproduction on plants treated with fluazifop-P, sethoxydim and imazethapyr was similar to the untreated control. COC or NIS alone were as effective as acifluorfen, bentazon or lactofen applications for reducing SCN reproduction. However, no additive effect of adjuvant-herbicide combinations was observed, nor did herbicide rate affect SCN reproduction. Treatments reduced SCN reproduction only when applied to soybeans and had no effect on SCN reproduction when applied directly to the soil. No treatment stimulated SCN reproduction relative to the untreated control. Soybeans treated with COC, NIS, acifluorfen and bentazon also had more glyceollin detected than of the untreated control. Herbicide-induced glyceollin production may have increased the resistance of soybean to SCN.