EFFECT OF PLANT EXTRACTS AND CULTURAL PRACTICES ON CUCUMBER MOSAIC VIRUS DISEASE OF CAPSICUM

Abstract

The present investigation was initiated to evaluate the effects of 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) for the management of cucumber mosaic viral disease of capsicum. The experiment was carried out at the research field of Sher-e-Bangla Agricultural University from November 2020 to April 2021. During the investigation, visual symptom observation and serological test, DAS-ELISA, confirmed that Cucumber mosaic virus (CMV) had infected capsicum and various types of symptoms like a mosaic, shoestring leaf, vein banding and stunted growth were observed in the field. The highest CMV incidence and severity were found on T 0 (control), 75% and 45% respectively, whereas the lowest CMV incidence (8.33%) and severity (22.30%) was observed on T 4 (neem leaf extract). The tallest plants (35.75 cm) were found in T 5 (aluminium foil as reflective mulch) and the shortest plants were seen in T 0 (control), 30.33 cm. The maximum number of healthy leaves were observed in T 5 (aluminium foil as reflective mulch) whereas the lowest number healthy leaves were found in T 0 (control). The lowest infected leaves and minimum leaf area reduction (24.33%) was observed in T 4 (neem leaf extract) compared to T 0 (control). Yield attributes were highest in T 5 (aluminium foil as reflective mulch) which were the highest number of fruits per plant (13.33), heaviest fruits (62.10 g), highest fruit yield per plant (725.74 g), highest yield per plot (2.78 Kg), highest total yield (5.56 ton/ha) and lowest yield loss (17.68%) compared to T 0 (control). A significant decrease in the number of aphids per leaf was observed in T 4 (neem leaf extract) compared to T 0 (control) and other treatments. The correlation-regression analysis established that there was a positive correlation between CMV incidence and severity. Total yield negatively correlated with CMV incidence (%) and severity (%) with 74.2% and 95.7% yield reduction due to an increase of CMV incidence and severity, respectively.