Relationship between Weather Parameters and Incidence of Gram Pod Borer, Helicoverpa armigera on Chickpea

Abstract

Background: Chickpea, Cicer arietinum which is considered as a “King of pulses” get adversely affected by several biotic and abiotic stresses, out of which gram pod borer, Helicoverpa armigera (Hübner) is the major one. The damage caused by H. armigera starts from vegetative growth and continues till maturity of the crop. This pest is causes 25 to 70 per cent pod damage in chickpea but in favorable conditions pod damage goes upto 95 per cent. Methods: Present study was carried out during, rabi, 2014-15 and 2015-16 at Research Farm, College of Agriculture, Bikaner (Rajasthan). Correlation coefficient was worked out with weather parameters such as temperature (maximum and minimum), relative humidity (maximum and minimum), rainfall and sunshine hours. Multiple linear forms of regression model were also used to assess the effect of the weather parameters on the incidence of pod borer. Result: The studies revealed that peak larval population of gram pod borer was recorded in the second fortnight of February thereafter, population declined abruptly. The larval population of pod borer on chickpea occurred low at vegetative and flowering stages and high at pod formation as well as at grain developmental stages. The temperature (maximum and minimum) and sunshine hours had significant positive correlation with larval population during rabi, 2015-16. The maximum relative humidity showed significant negative correlation during rabi, 2015-16 whereas, minimum relative humidity showed significant negative correlation with larval population during both the seasons. The rainfall showed significant positive correlation during rabi, 2014-15.