Persistence of activity of oxamyl against Heterodera schachtii on cabbage.

The duration of effectiveness of a foliar spray of oxamyl against Heterodera schachtii and the location of the protective effect were determined by applying a foliar spray at 0.04 kg (a.i.)/100 liters of water to cabbage seedlings. Oxamyl, or a metabolite of oxamyl, apparently is translocated to anti becomes prolective in the root within 7 days. Between 7 and 14 days, the location of the protection shifts from within the root In the root surface or rhizosphere. The chemical remains active for at least 21 days unless it is removed from the root or rhizosphere by washing with water.