In-Vitro and In-Vivo Effects of Aldicarb on Survival and Development of Heterodera schachtii.

Aqueous solutions of 5-500 mug/ml aldicarb inhibited hatching of Heterodera schachtii. Addition of hatching agents, zinc chloride, or sugarbeet root diffusate, to the aldicarb solutions did not decrease the inhibition of hatching. When cysts were removed from the aldicarb solufions and then treated for 4 wk in sugarbeet root diffusate, larvae hatched and emerged. Treatments of newly hatched larvae of H. schachtii with 5-100 mug/ml aldicarb depressed later development of larvae on sugarbeet (Beta vulgaris). Similar treatments with aldicarb sulfoxide had less effect on larval development, and aldicarb sulfone had no effect. Numbers of treated larvae that survived and developed were inversely proportional to concentration (0.1-5.0 mug/ml) and duration (0-14 days) of aldicarb treatments. Development of H. schachtii on sugarbeet grown in aldicarb-treated soil was inversely proportional to the concentration of aldicarb in the tested range of 0.75 - 3.0 mug aldicarb/g of soil. Transfer of nematode-infected plants to soil with aldicarb retarded nematode development, whereas transfer of plants first grownin treated soil to nematode-infested soil only slightly suppressed nematode development. Development of H. schachtii was inhibited in slices of storage roots of table beet (B. vulgaris), sugarbeet and turnip, (Brassica rapa), that had grown in soil treated with aldicarb.