North cotton growing zone of India witnessed another whitefly outbreak within a decade

Abstract

Whitefly, Bemisia tabaci (Gennadius), is a polyphagous and important pest of cotton worldwide. Both adults and nymphs of B. tabaci affect the crop by causing direct and indirect damage. A severe outbreak of whitefly was experienced during 2015 in North India on cotton followed by the outbreak during 2022 cotton season. During 2015, whitefly crossed and persisted above ETL (Economic Threshold Level is 18adults/ 3 leaves) between 28th - 35th SMW but during 2022 stayed above ETL between 27th - 36th SMW and peak incidence noticed during 31st and 29th SMW , respectively. So in 2022, early pest buid up in the form of ETL as well as peak activity indicating longer persistence (≥10 weeks ) of whitefly and high severity in terms of average whitefly population during season resulted in more damage to cotton crop. Additionally , farmers’ field survey data during 2022, showed whitefly population crossed ETL at 585 out of 1317 locations (44.42 percent) and during 2015, 620 out of 1089 locations (57 per cent ) were recorded above ETL indicating that unlike 2015; 2022 outbreak was not uniform in the entire zone wherein only few blocks of Punjab, Haryana and Rajasthan recorded severe infestations of whitefly.