Identification of resistant sources and management of Bean Common Mosaic Virus (BCMV) infecting cowpea

Abstract

The present investigation was undertaken to identify the resistance source and to find out the effectiveness of different pesticides for the management of the Bean Common Mosaic Virus (BCMV) infecting cowpea through aphid vector management. Screening was undertaken to test the resistance of 100 minicore collection of cowpea against BCMV under field conditions at College of Agriculture, Vijayapur during Kharif 2022-23. A local check (DC 15) was planted after every ten lines and along the four sides of the field to serve as a source for the disease through infector row technique. The per cent disease incidence was recorded at 15 days interval starting from 15 days after sowing up to maturity. The results reflected that among the 100 minicore accessions screened against BCMV, 15 germplasm lines showed immune reaction with no infection i.e., EC723782, EC724420, EC723677, EC724774, EC723836, EC724035, EC723741, EC724453, EC72808, EC723693, EC724051, EC723800, EC724500, EC724516 and IC91556. To know the effectiveness of different pesticides against aphids transmitting Bean Common Mosaic Virus, the experiment consisting of eight treatments with three replications was initiated. Different treatments were imposed at 15 days after sowing and subsequent sprays at 15 days interval (three times). Then, BCMV disease incidence was worked out at 30 days, 45 days, 60 days, 75 days and 90 days after sowing. Amongst eight treatments, imidacloprid 30.5 SC @ 0.3 ml/l had the highest reduction of aphid population over control and also had the lowest disease incidence and the maximum yield of 11.18 q/ha with the highest B: C ratio of 2.83. Flonicamid 50 WG @ 0.5 g/l and thiamethoxam 25% WG @ 0.2g/ l also reduced the disease incidence over control by more than 58 per cent. The aphid population and incidence of disease decreased after each spray.