Effects of Selected Nematicides on Hatching of Heterodera schachtii

Aldicarb, carbofuran, fensulfothion, and phenamiphos were tested in concentrations of 1-100 mug/ml for their effects on hatching of Heterodera schachtii. Exposure of cysts to 1 mug aldicarb or carbofuran/ml stimulated hatch whereas phenamiphos and, to a lesser degree, fensulfothion inhibited hatch. Addition of aldicarb to sugarbeet root diffusate or 4 mM zinc chloride suppressed activities of these hatching agents. Transfer of cysts previously treated with aldicarb or carbofuran to zinc chloride or water rapidly initiated hatch which finally exceeded the hatch from cysts not treated with the nematicides.