Abstract:
Abstract Cucumber mosaic virus (CMV) is non-persistently transmitted by aphids, rendering chemical insecticides ineffective. The effects of various plant extracts (neem leaf extract, garlic bulb extract, mahogany bark extract) and cultural practices (aluminium foil as reflective mulch, coriander as intercrop, marigold as border crop) on CMV incidence and severity were evaluated in capsicum at Sher-e-Bangla Agricultural University, Bangladesh. Mosaic, shoestring, vein banding and stunted growth were observed visually in the field and DAS-ELISA confirmed CMV infection in capsicum. Neem leaf extract resulted in the lowest CMV incidence (8.33%) and severity (21.67%), number of symptomatic leaves and the smallest percentage of leaf area reduction (%LAR) whereas the highest CMV incidence and severity, number of symptomatic leaves, and %LAR were observed in the untreated plots. However, the highest growth and yield parameters were recorded using aluminium foil as reflective mulch. Maximum plant height and the highest number of asymptomatic leaves were observed in aluminium foil as reflective mulch-treated plants. The highest fruit number per plant (13.33), heaviest fruits (62.10 g), highest fruit yield per plant (725.74 g), highest plot yield (2.78 kg), highest total yield (5.56 ton/ha) and lowest yield loss (17.68%) were observed in aluminium foil as reflective mulch. Neem leaf extract effectively decreased the number of aphids per leaf. Total yield negatively correlated to CMV incidence and severity with 74.2% and 95.7% yield reduction respectively, indicating that effective management of CMV will lead to higher yield.
