Residues of Propargite in Tea

Propargite is an acaricide extensively used in India for controlling the populations of the red spider mite (RSM) infesting tea. Field experiments were conducted at two places in Tamil Nadu (India) during the dry season to determine the residues of propargite in black tea. Residues were quantified at different harvest intervals of ‘0' (3 hr), 1st, 3rd, 5th, 7th, 10th and 14th day after acaricide application. Persistence, issipation pattern, half-life value and safe harvest interval of the acaricide in tea were calculated. Residues of propargite dissipated exponentially after application at both the locations and reached below the CODEX MRL of 5 mg/kg on the 7th day. Regression lines drawn on propargite showed that like other acaricides it followed the first order dissipation kinetics. Half-life values varied from 1.63 to 1.92 days for propargite and a safety harvest interval of 7 days is suggested for the tea crop.