Population Dynamics of Pod Borer Helicoverpa armigera (Hubner) on Chickpea

Abstract

A field experiment was carried out to study the population dynamics of pod borer Helicoverpa armigera (Hubner) on chickpea at the Agronomy Farm, College of Agriculture, Swami Keshwanad Rajasthan Agricultural University, Bikaner during two consecutive seasons i.e. rabi 2021-22 and 2022-23. The incidence commenced from first and second week of December i.e. 49^th and 50th Standard Metrological Week (SMW) and disappeared in the first fortnight of January. Incidence again started from the third week of January (3^rd SMW) which increased gradually and reached peak (6.4 and 5.2 larvae/ m row) in the third and second week of February (8^th and 9^th SMW) during first and second season. These peaks coincided with the vegetative, flowering, and podding stages. The correlation studies showed that incidence has a positive significant correlation with temperatures (p<0.01) while, morning (r = -0.609 and -0.640, p<0.05) and evening relative humidity (r = -0.728, p<0.01 & -0.666, p<0.05) showed negative significant correlation. Further, stepwise linear regression model indicated that maximum temperature as single predicator independent variable had the strongest relationship with incidence based on high R² value (61% and 63.40%). This forewarning regression model may help the farmers to take advance decision so as to minimize the damage caused by pod borer on chickpea.