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ThesisItem Open Access Eco-friendly Management of Rice Weevil, Sitophilus oryzae (L.) on Stored Wheat(CSKHPKV, Palampur, 2018-09-29) Mehta, Vasu; Surjeet KumarThe studies were conducted in the laboratory of the Department of Entomology, CSKHPKV, Palampur, India during 2017-18 with the objectives to determine relative susceptibility/resistance of seven cultivars of wheat to rice weevil, Sitophilus oryzae (L.) and to evaluate different plant powders as grain protectants against the weevil. The main aim of the study was to find eco-friendly alternatives to the chemical fumigants used against the weevil in stored wheat. On the basis of biological parameters of rice weevil and extent of its damage none of the varieties was found to be free from weevil infestation and damage. However, HPW-249, HPW-349 and HPW-360 were observed to be less susceptible, HPW-155, HS-490 and VL-892 were categorized as moderately susceptible and HPW-236 was highly susceptible. Among seven varieties, HPW-360 had the lowest oviposition (17.33%) and adult emergence (23.33 adults), the longest developmental period (43.67 days), the lowest monthly increase in population (87.0 days), the lowest value of susceptibility index (7.19) and orientation of the weevil (4.33 adults) and least grain damage (26.22%) and weight loss (6.59) while HPW-236 had the highest oviposition (64.0%) and adult emergence (87.33 adults), maximum orientation (27.33 adults) and monthly increase in population (243.44), highest value of susceptibility index (13.55), grain damage (58.67%) and weight loss (18.92%). Different plant powders, evaluated for their effects on the adult mortality and population build-up of S. oryzae and on the extent of damage by the weevil, proved highly effective in comparison to untreated control. The leaf powder of Ageratum conyzoides proved to be the best treatment against the weevil which resulted into maximum mean cumulative mortality (96.67%), the lowest monthly average of population increase (18.33) and the least grain damage (12.61%) and weight loss (1.75%) in six months of storage. The next best treatment was the drupe powder of Melia azedarach followed by Vitex negundo and Ocimum sanctum. These treatments did not cause significant reduction in seed germination. A. conyzoides, M. azedarach and O. sanctum were found effective even after three months of their preparation. The leaf powder of Murraya koenigii resulted into the lowest mean cumulative adult mortality (14.23%), the highest monthly increase in population (132.78), the highest grain damage (47.50%) and weight loss (11.07%) and the lowest germination (21.67%) after five months of treatment. Thus, this treatment proved to be the least effective against the weevil.