Carryover of Callosobruchus maculatus (Fab.) in Pigeon Pea Seeds from Field to Storage and its Management by Smearing Oil on Seeds

Background: Pigeonpea, Cajanus cajan (L.) is a vital pulse crop in South Asia, with India accounting for 90% of it’s global production. Its protein content (21-25%) is essential for nutrition and plays significant role in improving food security and nutrition in regions with limited resources. The insect pest attacks in Pigeonpea cause significant amount of grain loss in field and storage, the research was carried out to investigate the carryover of pest from field to storehouses and to study the efficacy of oils on C. maculatus management in which literature available is scarce. Methods: This study was carried out at Sardar Vallabhbhai Patel University of Agriculture and Technology Meerut, U.P., India during the year 2020-2022. Pigeonpea seeds were collected from research farm threshing floor of ICAR-IIFSR, Meerut. Infestations of pulse beetle carried from field to storage was studied on basis of mean no. of eggs laid and mean seed damage caused by beetle. To study efficacy of oils, the seeds were subjected to linseed, mustard, soybean, rice bran, safflower, castor, mahua and neem oil each at concentrations of 0.20, 0.50 and 1.00 ml per 100 g of seeds and five pair of beetles of same age were released into each container and removed after 5 days to study the damage incurred. Result: In the carryover study, maximum oviposition (16.88 eggs) was recorded on freshly harvested seeds that were kept open in storehouse for infestations which witnessed field as well as storage egg laying. Oils application on seeds showed 1ml oil per 100 g seed as most suitable dosage and neem oil, castor, mahua as most successful oil providing beetle control in terms of oviposition, damage and adult survival. Residual action of oil on seed surface after 3 months revealed different oil treatments showed significant reduction in the number of eggs laid, adult emergence and seed damage due to C. maculatus in pigeonpea seeds in comparison to control. Mean reductions in the number of eggs, adult emergence and seed damage were relatively higher in all the oil treatments.