Field Bio-efficacy of Some New Insecticides and Tank Mixtures against Whitefly on Cotton in New Alluvial Zone of West Bengal

The results of field experiments conducted during rabi seasons of 2012–13 and 2013–14 to evaluate twelve insecticidal treatments along with a untreated control are reported. Among the insecticides or insecticide mixtures, spiromesifen+imidacloprid was found superior in reducing the whitefly population count (2.24 per three leaves) as compared with 13.95 per three leaves in untreated plot. Reduction of whitefly population over control after two sprays was 83.94 per cent in spiromesifen+ imidacloprid followed by spiromesifen (80.39%), flupyradifurone (80.15%), sulfoxaflor+ buprofezin (75.73%), clothianidin (74.60%), buprofezin (73.67%), imidacloprid (73.40%), flonicamid + buprofezin (70.44%), sulfoxaflor (68.39%), dinotefuran+ buprofezin (67.51%), flonicamid (66.60%) and dinotefuran (64.04%) Average seed cotton yield was the highest in spiromesifen+ imidacloprid (379.72 kg ha⁻¹) and lowest in control (123.98 kg ha⁻¹). All the insecticides proved relatively less toxic to coccinelids and spider population.