EFFECTS OF 8 HERBICIDES ON IN-VITRO HATCHING OF HETERODERA-GLYCINES

Laboratory studies were conducted to evaluate effects of selected herb icides on hatching of free eggs of the soybean cyst nematode, Heterode ra glycines. The herbicides used were Atrazine (atrazine), Basagran (b entazon), Bladex (cyanazine), Blazer (acifluorfen), Command (clomazone ), Lasso (alachlor), Sonalan (ethalfluralin), and Treflan (trifluralin ). Treatments comprised two concentrations of commercial herbicide for mulations and deionized water and 3.14 mM zinc sulfate as negative and positive controls, respectively. Eggs were extracted from females and cysts, surface disinfested, and incubated in herbicide or control sol utions at 25 +/- 2 C in darkness. Hatched second-stage juveniles were counted every other day for 24 days. Hatching of H. glycines eggs in 5 0 and 500 mug/ml Blazer was 42 to 67% less than that in deionized wate r and 61 to 78% less than that in zinc sulfate solution. Zinc sulfate significantly increased hatching activity in 50 mug/ml but not 500 mug /ml Blazer. The other herbicides tested at various concentrations had no significant effect on egg hatching. The specific component of Blaze r inhibiting egg hatching is unknown. Suppression of hatching by Blaze r indicates that this postemergence soybean herbicide may have a poten tial role in managing H. glycines.