Management of Hoppers in the High Altitude Rainfed Rice Agroecosystem
Studies were conducted to evaluate some promising insecticides as foliar application for their bioefficacy against plant and leaf hoppers and toxicity against predators of high altitude rainfed rice at Hybrid Rice Evaluation Centre, Tamil Nadu Agricultural University, Gudalur during 2010 - 2012. Imidacloprid 17.8 SL @ 30 g a.i. ha−1 and buprofezin 25 SC @ 200 g a.i. ha−1 were highly effective in checking the population of green leaf hopper and brown plant hopper by registering almost cent per cent control after three rounds of spray, followed by triazophos 40 EC @ 400 g a.i. ha−1, monocrotophos at 450 g a.i. ha−1, methyl demeton at 250 g a.i. ha−1recorded around 55.3 to 82.2 per cent reduction of leaf and plant hoppers over untreated control. Botanicals such as E. adinophoram leaf extract @ 5%, neem oil @ 3% and NSKE @ 5% were less effective than insecticides which were recorded only 35.3 to 62.4 per cent reduction of hoppers over control. The results of three season trials revealed that, all the insecticides were harmful to the population of spiders, coccinellids and rove beetles than botanicals. The order of relative safety to natural enemies based on the percent reduction over control were, E. adinophoram leaf extract @ 5% > neem oil @ 3% = NSKE @ 5% > buprofezin 25 SC @ 200 g a.i. ha−1= imidacloprid 17.8 SL @ 30 g a.i. ha−1 > triazophos 40 EC @ 400 g a.i.ha−1 > monocrotophos 36 SL @ 450 g a.i.ha−1= methyl demeton 25 EC @ 250 g a.i.ha−1.