Influence of meteorological factors on the infestation of Aphis craccivora Koch in green gram varieties.
Infestation of A. craccivora was studied on kharif green gram cultivars PM-2 and Kopergaon, in the experimental farm of Assam Agricultural University, Jorhat, India. Aphid infestation started in the second week of November in the susceptible cultivar PM-2. In Kopergaon, which is known to be resistant, the aphid appeared in the 4th week of November. Peak infestations were reached in both cultivars simultaneously (2nd week of December). Maximum temperature, minimum temperature and relative humidity showed negative correlation with aphid infestation.