Chemical management of termites (Odontotermes obesus) in preserved setts of sugarcane (Saccharum officinarum)
Sudhansu Bhagawati, Badal Bhattacharyya, Himangshu Mishra and Dhanalakhi Gogoi
Field efficacy of some newer insecticides was evaluated against Odontotermes obesus in preserved setts of sugarcane at Assam Agricultural University, Jorhat during 2014-15. Three budded setts were treated with insecticides for one hour and were preserved by adopting “deep trench trash cover” method, in which seed stalks were vertically kept in narrow trenches with depth equal to the length of the stalks. In case of untreated control the setts were preserved horizontally. Experimental results indicated that all the insecticidal treatments were significantly superior over the untreated control in reducing termite infestation. The setts treated with clothianidin 50 WDG at concentration of 1ml/ lit registered the lowest infestation of termites (5.55 and 6.18% as number and portion infested respectively) and this treatment showed statistical parity with the combined application of acephate 50 per cent and imidacloprid 1.8 per cent at concentration 1ml/ lit treated setts (7.49 and 8.59%). Highest mean germination of eye buds was recorded in clothianidin 50 WDG treated setts (79.41%) followed by acephate 50% + imidacloprid 1.8% SP (72.49%) and imidacloprid 17.8 SL (71.94%) treated setts. The untreated control setts showed very high levels of termite infestation (82.93 and 78.37% based on number and portion of sett infested respectively) with 46.94 per cent sett germination exhibiting the impact of termite infestation when the setts were preserved before planting.