Incidence, detection and integrated management of viral disease complex in Bhut Jolokia, a Chilli cultivar in Assam

Abstract

Double antibody sandwich ELISA (DAS-ELISA) and polymerase chain reaction (PCR) assays detected the infection of four viruses viz., Cucumber mosaic virus (CMV), Potato virus Y (PVY), Groundnut Bud Necrosis Virus (GBNV) and Chilli leaf curl virus (ChLCV) in Bhut Jolokia with 55.0% infection by CMV, 36.0% by PVY, 44.9% by GBNV and 42.5% by ChLCV in Assam. Plants were found to be infected by single virus or more than one virus together forming a disease complex. The various symptoms manifested by these viruses on Bhut Jolokia includes mosaic, puckering, dwarfing, leaf size reduction, upward and downward curling of leaves, flower bud necrosis, etc. An integrated management approach which included treatments in nursery and main field condition, was developed in order to combat the infection of the plants due to viral disease complex. Among the treatment combinations, T12 [seed treatment with imidacloprid@0.25 ml/l + nursery net+ foliar spray with imidacloprid @ 2ml/l at 15, 30, 45, 60 DAT] was the most effective in reduction of disease incidence and vector population count with maximum yield of 91.27 q/ha. Disease incidence of 14.8% (CMV+PVY), 7.4% (ChLCV), 11.1% (GBNV) with average of 11.1% and average vector population count of 3.19 nos.(aphid), 3.43 nos.(whitefly) and 16.33 nos.(thrips) were recorded in the treatment T12 which was much lesser as compared to control.