Influence of weather variables on whitefly population build-up and progression of okra yellow vein mosaic virus disease

This study was conducted to determine the impact of environmental conditions on whitefly population development and OYVMV progression. The increase in the whitefly population began in July and peaked in the first week of October due to favourable climatic circumstances, with maximum temperatures of 34 ± 2°C and minimum temperatures of 23 ± 2°C, morning relative humidity of more than 90%, wind speed of about 3 km/h, more sunshine hours, and no rain. Pusa Sawani (6.54) had the highest average whitefly population, followed by Pusa A4 (5.27) and Varsha Uphar (3.78). During the first week of October, the terminal PDI was highest in Pusa Sawani (73.00%) and lowest in Varsha Uphar (18.75%). In all three cultivars, whitefly population and PDI had a positive relationship with bright daylight hours and morning relative humidity. The highest temperature was positively correlated with the whitefly population and adversely correlated with PDI. However, whitefly population and OYVMV disease were negatively correlated with evening relative humidity, wind speed, and rainfall.