Karnatak, A.K.Rawat, Nistha2021-01-292021-01-292020-01https://krishikosh.egranth.ac.in/handle/1/5810160698The present investigation was carried out during two seasons i.e., kharif season 2017 and winter season, 2017-2018 at Vegetable Research Centre (VRC), G.B. Pant University of Agriculture and Technology, Pantnagar. Occurrence of 22 species of insect pests belonging to 4 orders and 14 families found attacking on Okra crop. Among the various pest complex of Okra the order Hemiptera occupied largest number of species constituting 6 pests species of total pests followed by Lepidoptera(4 species), Coleoptera (2 species) and one each belonging to orders, Orthoptera, Thysanoptera, Diptera and Acarina. In kharif, 2017 the pooled incidence of Earias spp. was observed from 28th standard metrological week (SMW) to 39th standard metrological week (SMW). The pest marked its first appearance by average of 2.1 larvae/plant at 32nd standard metrological week (SMW). The population gradually increased and attained maximum (5.9 larvae/plant) in the 37th standard metrological week (SMW). The incidence of the Amrasca biguttula biguttula was recorded from 30th standard metrological week to 39th standard metrological week (last week of September).The first appearance of this pest was marked by an average of 0.83 leaf hopper/3leaf in 30th standard metrological week.The population gradually increased and attained maximum (11.13 hopper/3 leaves) in the 37th standard metrological week (SMW) followed by gradual decrease in population till 39th standard metrological week (SMW). While, incidence of Bemisia tabaci, was recorded from 30th standard metrological week to 39th standard metrological week and Aphis gossypii was observed throughout the crop season exhibiting a population range from 0.01 to 4.03. The population gradually increased and attained maximum (29.7aphids/3leaf) in the 36th standard metrological week (SMW). Different Organic and IPM Modules were developed for management of major insect pest in okra.It revealed that Organic Module 3 in kharif season and Organic Module 4 and Organic Module 3 in winters season gave significant results followed by IPM Module1 for the management of Okra shoot and fruit borer (Earias vittella Fab.). But in case of sucking pests (whitefly, hoppers and aphids) chemical treatments T6 (Imidacloprid 17.8 SL) and T7 (Acetamiprid 20% SP) gave significantly best results followed by IPM Modules T5 and T6. In case of sucking pests (whitefly, hoppers and aphids) the population of pest in organic modules were significantly lower than untreated control but not statistically similar to chemical and IPM modules. The population of natural enemies on both seasons were statistically similar in organic modules, untreated control, IPM Modules (all at par with each other) and the lowest population of natural enemies was found in both chemical fields although it was not significantly lower but as compared to other treatments. During kharif 2017, yield of Okra under different treatments varied significantly from 10.01 to 14.28 T/ha. Maximum fruit yield (14.28 T/ha) was recorded from plot treated with Imidacloprid 17.8 SL @ 20g a.i./ha. This was followed by Acetamiprid @ 600 g a.i./ha (14.20 T/ha) IPM Module 1(14 T/ha), Organic Module 3 (13.79 T/ha), IPM Module 2 (13.50 T/ha), Organic Module 4 (13.49 T/ha), Organic Module 1 (13.29 T/ha), Organic Module 3 (13.11 T/ha). Lowest fruit yield (10.01 T/ha) on the contratry was recorded with control plot. Also in winter 2017-2018 the maximum yield was recorded in Imidacloprid 17.8 SL @ 20g a.i./ha (15.03 T/ha). The yield of Okra under different treatments varied significantly from 9.7 to 15.03 T/ha. Maximum fruit yield was recorded from plot treated with Imidacloprid 17.8 SL @ 20g a.i./ha. This was followed by Acetamiprid @ 600g a.i./ha (14.88 T/ha), IPM Module 1 (14.75 T/ha), Organic Module 3 (14.70 T/ha), IPM Module 2 (14.48 T/ha), Organic Module 4 (14.04 T/ha), Organic Module 1(13.99 T/ha), Organic Module 3 (13.61 T/ha). Lowest fruit yield (9.7 T/ha) as recorded with control plot. Maximum benefit cost ratio was observed in both chemical Modules (Imidacloprid 17.8 SL with 1:2, Acetamiprid 20% SP @ 600g/ha with 1.93) followed by both IPM Modules (IPM 1 with 1:1.89 and IPM 2 with 1:1.82), Organic Modules 2 with 1:1.56, Organic Modules 4 with 1: 1.37, Organic Modules 1 with 1:1.37, Organic Modules 3 with 1:1.34. Organic Modules 2 was comparatively economical than other Organic Modules, but more benefit was observed in Chemical and IPM Modules. However, the yield was higher in chemical modules but this may lead to pest resurgence, problem of secondary pest outbreak and affect the food chain by leaving residues on crop. Hence, to overcome these ecological as well as health problems the basic and important solution is to return back to organic farming. Nowadays, due to awareness among people they prefer organic produce and there may be higher profitability for farmer by adopting organic approach.EnglishThesis