Shukla, AbhishekArunkumar, Harne Anjali2016-07-152016-07-152014http://krishikosh.egranth.ac.in/handle/1/68797ABSTRACT Present experiment entitled” Studies on insect- pests incidence on chilli, Capsicum annum Linn. and evaluation of insecticides for their management,” was conducted to record the insect pests appearing on this crop in Jabalpur region and to evaluate certain insecticides for their management. Investigations were conducted with the following objectives: 1. To study the population dynamics and succession of insect pests and their natural enemies on chilli. 2. Evaluation of comparative performance of foliar application of insecticides for the management of insect- pests on chilli. 3. Studies on the incidence of chilli thrips, S. dorsalis Hood on chilli and its correlation with leaf curl incidence. In present experiment four insect species were observed infesting chilli crop at different stages namely whiteflies, Bemisia tabaci, thrips, Scirtothrips dorsalis, gram pod borer, Helicoverpa armigera and tobacco caterpillar, Spodoptera litura. The infestation of Bemisia sp. was first observed in the second week of November at crop 7 days after transplanting the crop with a population 1.4 individual/ 10 cm twig. The population of Bemisia sp. remained between 0.4 and 3.46 individuals during the crop season. Highest population was observed in second week of December with 3.46 individuals /10 cm twig, at 35 days after transplanting. The pest remained active till the maturity of the crop. Whiteflies population did not show correlation with any abiotic factors. The infestation of thrips also started from second week of November at 7 days after transplanting with the population of 1.04 individuals/ 6 leaves, and it continued till the end of the crop season. Highest population was observed in second week of March with 3 individuals/ 6 leaves at 126 days after transplanting. The pest remained active till the maturity of the crop. Thrips population show significant positive correlation with maximum temperature. The population of Helicoverpa armigera was first observed in the first week of March, 119 days after transplanting, with 0.5 individuals/ sample and it continued till the end of the crop season. Highest population was observed in second week of March with 1.1 individuals/ sample. The pest remained active crop the maturity. Gram pod borer population did not show any correlation with any of the abiotic factors. The tobacco caterpillar population was first observed in third week of March, 133 days after transplanting with 0.76 individuals/ sample. The pest remained active till at the end of the crop season. Tobacco caterpillar populations did not show any correlation with any abiotic factor. In present experiment, four insecticides namely Triazophos 40EC,Dimethoate 30EC, Imidacloprid 17.8 SL, Fipronil 5 SC and their different doses were evaluated against the incidence of insect pests namely thrips, Scirtothrips dorsalis (Hood), whiteflies, Bemisia tabaci, fruit borer, Helicoverpa armigera and tobacco caterpillar, Spodoptera litura. Three sprays of different treatments were given to the crop at 15 days interval. The pre-treatment observation were recorded 24 hours before spraying, while the post treatment observations were recorded at 3, 7 and 14 days after each spraying. Populations of whiteflies, Bemisia tabaci were recorded by observing leaves of 10 cm twig, on every plant using glass frame, while population of thrips, Scirtothrips dorsalis was counted on six leaves (i.e., 2 upper, 2 middle and 2 lower canopy leaves). Significant differences were observed among treatments. Lowest whitefly population per 10 cm twig was recorded in treatment Fipronil 5 SC @ 0.350 l/ha (1.92, whiteflies /sample), followed by Dimethoate 30 EC@ 0.580 l/ha (1.98), Triazophos 40 EC @ 1.050 l/ha (2.03), Triazophos 40 EC @ 0.7 l/ha (2.03), Fipronil 5 SC @ 0.525 l/ha (2.05), Imidacloprid 17.8 SL @ 0.058 l/ha (2.07), Dimethoate 30 EC @ 0.875 l/ha (2.08) and Imidacloprid 17.8 SL @ 0.09 l/ha (2.20), that were at par. Highest whitefly population per 10 cm twig was recorded in untreated control (2.63). Significant differences were observed among treatments. Lowest thrips population / sample (i.e., 6 leaves, 2 upper+ 2middle + 2 lower) was recorded in treatment Fipronil 5 SC@ 0.350 l/ha (1.34, thrips/sample) followed by treatments Imidacloprid 17.8 SL @ 0.09 l/ha (1.39), Imidacloprid 17.8 SL @ 0.058 l/ha (1.5), Triazophos 40 EC @ 0.7 l/ha (1.51), Dimethoate 30 EC @ 0.580 l/ha (1.6), Triazophos 40 EC @ 1.050 l/ha (1.80) and Fipronil 5SC @ 0.525 l/ha (1.81), Dimethoate 30 EC @ 0.875 l/ha (1.77) that were at par. Highest thrips population per 10 cm twig was recorded in untreated control (2.58). Incidences of leaf curl disease were recorded throughout the crop season. Leaf curl incidence did not show any correlation with the mean populations of Scirtothrips sp. during different weeks.enchillies, crops, diseases, scirtothrips dorsalis, insecticides, planting, seasons, sampling, yields, research methodsThesis