1ICAR-Directorate of Onion and Garlic Research, Rajgurunagar, Pune410505, India
*Email: karuppaiahv2008@gmail.com (corresponding author)
The relationship between weather factors and incidence of thrips (nymphs and adults) was studied during 2012-17 at Rajgurunagar, Pune. The weekly incidence of onion thrips (Thrips tabaci) showed a peak during 4th standard meteorological week (SMW) with 64.5 thrips/plant. The incidence exhibited a significant correlation with maximum (MaxT) and minimum temperature (MinT), and morning relative humidity (MRH) for current, 1-lag and 2-lag week weather parameters. The pest load was observed to be with a significant correlation with MaxT, MinT, MRH and ERH (evening relative humidity) of 2-lag week. Stepwise regression using 2-lag week weather parameter MinT was the most important factor contributing by 82% variation in the incidence. Model was validated using 2017-18 data with R2 value of 0.737. Developed model reveal that the minimum temperature is the most important weather parameter determining the seasonal dynamics of onion thrips in western Maharashtra.
Onion, Thrips tabaci, Forewarning, Population dynamics, Regression model, Incidence, Peaks, Validation, Minimum temperature, Seasonal incidence, Western Maharashtra