Persistence and residual toxicitiy of propargite against Panonychus ulmi Koch (Acari: Tetranychidae) on Malus domestica Borkh

Abstract

The present investigation entitled “Persistence and residual toxicity of propargite against Panonychus ulmi Koch (Acari: Tetranychidae) on Malus domestica Borkh” was undertaken at the Division of Entomology, SKUAST-Kashmir, Shalimar. Propargite was sprayed on apple plants at three concentrations, following which bioassay was performed in the laboratory to establish persistence and residual toxicity. The period of effectiveness of propargite against P. ulmi was computed at each concentration and it was established that in case of highest concentration/ double the recommended concentration of propargite i.e. @ 0.1%, the mortality was observed till 15 days. This was followed by persistence till 13 days against the concentration of 0.05% which is the recommended concentration of propargite and the least persistence of 11 days was observed against the concentration of 0.025%. It was observed that double the recommended dose persisted for more time than the corresponding recommended and below the recommended doses.