Abstract: | Heterodera glycines (race 1) eggs were exposed to aqueous solutions o f selected concentrations o f the herbicide alachlor and the organophosphate nematicide phenamiphos alone and in herbicide-nematicide combinations. Phenamiphos (0.5 μg/ml) + alachlor (0.063, 0.125, or 1.0 μg/ ml) treatments increased the incidence o f juvenile hatch over that of untreated controls at 18 days. At 18 and 25 days, phenamiphos (0.5 μg/ml) treatments contained more juveniles than did phenamiphos at 1.0 μg/ml. Phenamiphos (1.0 μg/ml) alone and in combination with alachlor (1.0 μg/ ml) suppressed hatch for 21 days and juvenile survival for more than 21 days. Alachlor treatments enhanced juvenile survival compared to the untreated control at 14 and 21 days. Technical alachlor gave results similar to those of the formulated product. |