Efficacy of some acaricides against sugarcane web mite Schizotetranychus andropogoni hirst

The field experiment to evaluate insecticides against sugarcane web mite Schizotetranychus andropogoni Hirst was conducted at a farmer's holding at Alanganallur village (Alanganallur block, Madurai District) on sugarcane (variety Co 86032) during May 2016-April 2017 in a randomized block design (RBD) with nine treatments. The treatments include: spiromesifen 240 SC @ 168 g a.i./ha, etoxazole 10 SC @ 33 g a.i./ha, fenazaquin 10 EC @ 125 g a.i./ha, ethion 50 EC @ 625 g a.i./ha, fenpyroximate 5 EC 12.5 g a.i./ha, hexythiazox 5.45 EC @ 10.86 g a.i./ha, chlorfenapyr 10 SC @ 100 g a.i./ha, propargite 57 EC @ 712.5 g a.i./ha with an untreated check and three replications. Reduction of web mites was maximum in spiromesifen 240 SC @ 168 g a.i./ha (3.88/2 cm² area of leaves) followed by fenpyroximate 5 EC @ 12.5 g a.i./ha (4.00/2 cm² area of leaves) and the lowest in fenazaquin 10 EC @ 125 g a.i./ha (7.84/2 cm² area of leaves). Similarly, higher cane yield was recorded in spiromesifen 240 SC @ 168 g a.i./ha (109.61 t/ha) followed by fenpyroximate 5 EC @ 12.5 g a.i./ha (109.42 t/ha) as compared to the untreated check (101.05 t/ha). The cost benefit ratio was also higher in spiromesifen 240 SC @ 168 g a.i./ha (1: 2.98) followed by fenpyroximate 5 EC @ 12.5 g a.i./ha (1: 2.87).