Abstract

Two field experiments were conducted during October 2011 – January 2012 and October 2012 to January 2013 with blackgram variety CO 6 and CO 5 in farmer’s holdings at Kaliannanpudur and Valayapalayam, Coimbatore, respectively to evaluate the efficacy of lufenuron 5.4 EC at 20, 30, 40 and 60 g a.i. ha -1 against Maruca vitrata (Geyer). In the field experiments, lufenuron 5.4 EC at 60 g a.i. ha -1 reduced the flower damage by 66.05 and 88.37 per cent, respectively over untreated control after three rounds of spraying and cumulative reduction of flower damage was 56.07 and 74.60 per cent. The population of spiders was high in untreated control (5.51 and 6.53 per 10 plants, respectively), followed by lufenuron 5.4 EC at 20 g a.i. ha -1 (5.16 and 5.97 per 10 plants, respectively) which was on par with lufenuron 5.4 EC at 30 g, 40 g and 60 g a.i. ha-1 . The highest yields of 900.50 kg ha -1 and 937.50 kg ha-1 , respectively were obtained in plots treated with lufenuron 5.4 EC at 60 g a.i. ha -1 in both trials.

Keywords: IGR, lufenuron, Maruca vitrata, Blackgram, Bio-efficacy, Yield.