Population dynamics of gram pod borer (Helicoverpa armigera Hubn.) in relation to abiotic factors on field pea

Abstract

To study the seasonal incidence of gram pod borer in field pea ecosystem four experiments were conducted at Research Farm of Bidhan Chandra Krishi Viswavidyalaya, Mohanpur during rabi seasons of 2015-16 to 2018-19. The study revealed that the infestation of this pest was highly influenced by different weather parameters. The activity of larval population started in the field from 2nd, 3rd or 4th SMW in different seasons.H. armigera population reached its peak during last week of January in 2017-18 at flowering stage and rest of the years in mid of February at pod maturity stage of the crop. Among the meteorological parameters taken into consideration maximum temperature, minimum temperature and bright sunshine hour had positive correlation with the pod borer population while maximum and minimum relative humidity showed negative correlation with the pest population. The multiple regression equation revealed that variations of different weather parameters caused approximately 64 to 88 percent variations in gram pod borer population in four seasons. These meteorological parameters determine the seasonal incidence gram pod borer in field pea and this information may be helpful to develop ecofriendly pest management practices.