RAMA RAO, C.V.PALAGANI, CHENNA RAO2019-03-162019-03-162018http://krishikosh.egranth.ac.in/handle/1/5810098734D5633A field experiment entitled “Impact of cultivation methods of rice on pest and defender population and management of leaf folder, Cnaphalocrosis medinalis Guenee with newer insecticides.” was conducted at Agricultural College Farm, Bapatla, during kharif 2017. In the investigations, population dynamics of insect pests and defenders in different planting methods (normal transplantation, system of rice intensification, dry direct sowing, wet direct sowing and drum seeding) of paddy and the efficacy of certain new insecticides against rice leaf folder in dry direct sowing method were studied. Among the different cultivation methods of rice on pest incidence revealed that the lowest mean per cent leaf damage by leaf folder was observed in dry direct sowing (5.30%) and drum seeding (5.33%), whereas the highest mean per cent leaf damage by leaf folder was recorded in normal transplantation (7.76%). In case of BPH and WBPH the lowest mean population per hill was observed in system of rice intensification (3.95 and 2.28), whereas the highest mean population of BPH and WBPH per hill was recorded in normal transplantation (8.89 and 4.66), respectively. Similarly, green leafhopper mean population per hill was lowest in system of rice intensification (1.21) and dry direct sowing (1.29) and the highest mean population per hill was recorded in normal transplantation (1.78). In case of natural enemy population, the mean population of mirid bugs per hill was highest in normal transplantation (4.71) method which was on par with drum seeding (4.56) and wet direct sowing (4.35), whereas in system of rice intensification the lowest mean population of 2.83 per hill was recorded. Similarly, the highest mean population of coccinellids per hill was observed in normal transplantation (1.06) and wet direct sowing (0.90) method, whereas the lowest mean population per hill was recorded in system of rice intensification (0.71). In case of spiders highest mean population per m2 was recorded in normal transplantation (3.53) and dry direct sowing (3.28) whereas in system of rice intensification the lowest mean population of 2.44 per m2 was noticed. The impact of cultivation methods of rice on grain yield indicated that system of rice intensification to be superior over other cultivation methods by recording grain yield of 6432.50 kg ha-1 which was on par with dry direct sowing and drum seeding with a grain yield of 6072.00 kg ha-1 and 5773.50 kg ha-1 respectively. Management of rice leaf folder with certain newer insecticides revealed that all the insecticide treatments were found superior over untreated control. Amongst them, flubendiamide 39.35% SC @ 0.3 ml l-1, chlorantraniliprole 9.3% + lambda cyhalothrin 4.6% ZC @ 0.8 ml l-1 and chlorantraniliprole 18.5% SC @ 0.3 ml l-1 were the most effective insecticides in reducing leaf folder infestation with 63.71, 56.72 and 54.80 per cent reduction over untreated control, respectively. The plots treated with flubendiamide 39.35% SC @ 0.3 ml l-1, chlorantraniliprole 9.3% + lambda cyhalothrin 4.6% ZC @ 0.8 ml l-1, chlorantraniliprole 18.5% SC @ 0.3 ml l-1 and flubendiamide 19.92% + thiachloprid 19.92% SC @ 0.5 ml l-1 recorded higher grain yield with 64.33, 63.46, 61.55 and 50.08 per cent increase over untreated control respectively.en-USnullThesis