Population dynamics of Chrysodeixis acuta (Walker) and Gesonia gemma (Swinhoe) infesting sunflower intercropped with pigeonpea and its correlation with weather parameters

Abstract

Investigations on seasonal incidence of semiloopers viz., Chrysodeixis acuta (Walker) and Gesonia gemma (Swinhoe) infesting sole sunflower and sunflower intercropped with pigeonpea were carried out on the Research Farm of Department of Agricultural Entomology, College of Agriculture, Latur (VNKMV, Parbhani) during Kharif 2017. The data revealed that C. acuta and G. gemma were emerged as major semiloopers on sole sunflower and sunflower intercropped with pigeonpea. The peak activity of C. acuta (6.0 and 8.4 larvae per quadrat) during 36th and 35th SMW, however the peak activity of G. gemma (2.0 and 1.0 larvae per quadrat) was registered during 33th and 34th SMW on sole sunflower and sunflower intercropped with pigeonpea, respectively. The larval population of C. acuta infesting sole sunflower and sunflower intercropped with pigeonpea exhibited positive correlation with rainfall, maximum temperature and beforenoon relative humidity, whereas number of rainy days showed negative correlation with larval population. The larval population of G. gemma infesting sole sunflower had a positive correlation with rainfall, beforenoon relative humidity, whereas number of rainy days and minimum temperature showed negative correlation with larval population. However, that rainfall exhibited significantly direct positive effect on larval population of G. gemma infesting sunflower intercropped with pigeonpea, whereas number of rainy days and minimum temperature showed negative correlation with larval population.