Seasonal occurrence of gram pod borer [Helicoverpa armigera (Hubner)] on chickpea in Varanasi
Durga Bahadur GM, Ram Keval, Sunil Verma and Kalpana Bisht
A study on the seasonal occurrence of Helicoverpa armigera on chickpea was studied at the Agricultural Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi during two consecutive years of 2016-17 and 2017-18. The study revealed that the H. armigera marked its first appearance during the 2nd standard week with a population of 1.21 larvae per plant and persisted up to 11th SW with 3.67 larvae per plants. Similarly, during 2017-18, H. armigera started appearance during 3rd standard week population is 0.94 larval per plant and persisted up to 12th SW with 1.54 larval per plants. Correlation studies revealed that in the year 2016-17 there was positive association with maximum temperature (r = 0.636), sunshine (r= 0.595) wind velocity (r= 0.480) evaporation (r = 0.630) and minimum temperature (r =.0.580), whereas negative relationship was found with the morning relative humidity (r = -0.706*), evening relative humidity (r = -0.320) and rainfall (r= -0148), However, during the year 2017-18 there was positive association with maximum temperature (r = 0.463), minimum temperature (r =.0.562), rainfall (r= 000), sunshine (r= 0.449), wind velocity (r= 0.166) and evaporation (r = 0.834**). While negative non-significant relationship was found with the morning relative humidity (r = -0.399), and evening relative humidity (r = -0.761*).