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.