摘要 : A field experiment was laid at Agricultural College and Research Institute, Madurai during June - November 2009 to evaluate the efficacy of various bio-control agents individually and in different combinations for the management o... 展开 A field experiment was laid at Agricultural College and Research Institute, Madurai during June - November 2009 to evaluate the efficacy of various bio-control agents individually and in different combinations for the management of major insect pests of coleus. Five releases of <i>Chrysoperla carnea</i> (50,000 eggs/ha) at monthly interval were effective in reducing the incidence of thrips (<i>Scirtothrips dorsalis</i>), recording the mean population of 8.2 nos./sq.cm with 60.0 per cent reduction over untreated check. Single release of <i>C. carnea</i> on 30 Days after Planting (DAP), <i>Trichogramma chilonis</i> on 60 DAP, single spray of <i>Beauveria bassiana</i> on 90 DAP and two rounds of spray of <i>Bacillus thuringiensis</i> on 120 and 150 DAP were effective against defoliator (<i>Orphanostigma abruptalis</i>), recording the lowest mean population of 2.6 nos./five plants with a reduction of 69.4 per cent over untreated check and the highest yield of 20,643 kg wet tubers/ha. 收起