S.LingappaC.M.Rafee2016-07-232016-07-232010http://krishikosh.egranth.ac.in/handle/1/69526The study was carried out to study the interaction of Gossypium herbaceum and Gossypium arboreum and G. hirsutum to pave way for designing strategies for development of IPM for desi cottons. Peak activity of aphids, leaf hoppers and thrips was at 105, 75 and 75 DAS, respectively. Gossypium hirsutum was susceptible to sucking pests Susceptibility to bollworms was G. hirsutum > G. herbaceum > G. arboreum. Peak activity of ABW, SBW and PBW was at 105, 90 and 105 DAS. Coccinellid and chrysopid population was corresponding to aphids. Helicoverpa armigera preferred G. herbaceum over G. arboreum. Preference for plant parts was leaves> bracts> stem> petiole. Trichogramma chilonis preferred G. arboreum cultivars over G. herbaceum. It was most efficient followed by T. achaea, T. japonicum, T. pretiosum, T. brasiliensis. Chrysopid preferred hairy genotypes for oviposition and not for feeding. Cotton with cowpea, sorghum and bhendi reduced the population of aphids and leaf hoppers in G. arboreum and G. herbaceum. Bhendi and cowpea had favourable influence to lower thrips activity. Drastic decline of H. armigera population when G. arboreum and G. herbaceum were intercropped with cowpea, sorghum and bhendi. Higher population of coccinellids and Chrysopids was noticed in G. arboreum cotton with cowpea, sorghum and bhendi. Significant higher cotton yield of 5.06, 4.73, 4.70 and 5.18, 5.05 and 4.62 q/ha in AK-235 and Jayadhar, respectively in above crop combinations. Highest B:C ratio was from bhendi, cowpea and sorghum intercrops combinations. Recommended package of practices recorded higher seed cotton yield followed by seed treatment + T. chilonis @ 2.0 lakh/ha at 90 and 110 DAS in G. arboreum and G. herbaceum, respectively. Residual toxicity of imidacloprid treatment to seed was upto 75, 60 and 45 days to leaf hoppers, aphids and thrips, respectively.Thesis