EFFECT OF SOWING DATES AND WEATHER PARAMETERS ON THE INCIDENCE OF HELICOVERPA ARMIGERA (HUBNER) IN CHICKPEA

Abstract

An experimental trial was conducted to confirm the optimum sowing date of chickpea to determine the infesta- tion of H. armigera and grain yield. It is observed that the incidence and population fluctuation of this pest was much dependent on the prevailed weather parameters during the cropping season of all seven different date of sowing. The overall minimum mean eggs population (3.04/10 plants) was recorded on early sown crop on November 07 which was significantly superior over the other sowing dates. Correlation analysis revealed that morning RH% exhibited significantly positive correlation with eggs population on November 07 (r= 0.60), December 27 (r= 0.64) and maximum temperature on December 17 (r= 0.57) while, significantly negative correlation (r= -0.61) was found with evening RH% on December 17 sown crop, respectively. Minimum larval population (1.74/mrl) was observed on November 07 sown crop which was significantly superior over other six sowing dates. Correlation coefficient of larval population with sunshine hours exhibited significantly positive correlation (r =0.55) on November 07 sown crop. Whereas, maximum temperature (r= 0.66) showed positively significant association with mean larval population while, both morning and evening RH% exhibited negative correlation (r= -0.54, -0.55) on November 27 sown crop. On December 07 sown crop, the correlation of mean larval population with maximum and minimum temperature was also exhibited significantly positive (r= 0.70, 0.62). Maximum grain yield 1855 kg/ha was recorded from early sown crop on November 07, whereas mini- mum yield 612 kg/ha was obtained from late sown crop of chickpea.