Management of Scirtothrips dorsalis in Grape

Three nicotinoid molecules (imidacloprid 17.8% SL @ 0.3 g, acetamaprid 20% SP @ 0.3g and thiamethoxam 25%WG @ 0.3g), dimethoate 30EC @ 1.7ml, azadirachtin 0.03% EC @ 5.0m/litre of water and water spray were evaluated against grape thrips Scirtothrips dorsalis Hood during 2006–07 and 2007–08. The three nicotinoid molecules were found on par with each other and superior over standard check dimethoate 30EC@1.7ml in reducing thrips injury on grape berries at seven, 14 and 21 days after treatment. In large scale studies conducted with two superior molecules viz., acetamaprid 20% SP and thiamethoxam 25%WG and standard check dimethoate 30%EC, the two nicotine molecules recorded lowest population of thrips per vine at five days after spraying (10.40 and 8.80 resply) and ten days after spraying (1.50 and 1.90 resply) after first spray wherein dimethoate recorded 27.85 and 11.00 thrips at 5 and ten days after spraying. Same trend was recorded after second spray also. Acetamaprid 20% SP yielded 29.6t/ha of healthy berry yield and thiamethoxam 25% WG recorded 29.8 t/ha. Dimethoate 30EC recorded 22.9 t/ha of berry yield across two years. Injury grade according to 0–10 grade rating scale is one for two nicotine molecules and two for standard check.