Persistence of Clodinafop Propargyl and its Metabolite in Soil and Wheat Crop under North Western Himalayan Region

Abstract

A field investigation was carried out to study persistence and accumulation of clodinafop-propargyl residues in wheat. Soil samples and wheat plant samples from field experiment were collected at 0 (2 h), 1, 3, 5, 7, 10, 15 and 30 days after herbicide application and at the crop harvest. In soil and plant both, the parent ester rapidly degraded to its major metabolite i.e. clodinafop acid. Clodinafop-propargyl @ 30 and 60 g/ha persisted in soil up to zero day after herbicide application, whereas at higher dose i.e. 120 g/ha clodinafop ester in soil persisted up to 3 days. In case of plant samples, clodinafop ester residues were detected only at zero day after herbicide application at two rates of clodinafop i.e. 60 and 120 g/ha. In all clodinafop applied treatments, more than 90 % of major metabolite clodinafop acid in soil dissipated within 10 days after herbicide application. The dissipation of clodinafop acid at all the levels of application in soil followed first order kinetics with half life varying from 1.89-3.01 days. Clodinafop acid in plant persisted up to 1 day after herbicide application at lower dose i.e. 30 g/ha whereas, at 60 g/ha persisted up to 3 days and at 120 g/ha persisted up to 5 days only. The wheat straw and wheat grain samples were free from residues of clodinafop ester and acid both.