Vol. 11, Special Issue 6 (2022)

Author(s):
Nivetha TK, Srinivasan G, Shanthi M, Gurusamy A and Vellaikumar S

Abstract:
Field experiments were carried out to study the seasonal incidence of Fall armyworm, Spodoptera frugiperda on maize during rabi 2019 and summer 2020 and the observations were taken at weekly intervals. The study revealed that the incidence of FAW started in 38^th MSW (0.52 larvae / plant) and the population increased gradually and reached the peak in 44^th MSW (1.20 larvae/ plant) which coincided with the maximum per cent infestation (53.72%) in rabi 2019. The incidence of FAW in summer 2020 started from 8^th MSW (0.69 larvae / plant), reached the peak in the 12^th MSW (1.69 larvae/ plant), which coincided with the maximum per cent infestation (58.33%). Correlation analysis in rabi season revealed that larval population and infestation showed a significant positive correlation with the evening relative humidity (r= 0.727) while maximum temperature, minimum temperature and rainfall exhibited negative association with larval incidence and infestation of S. frugiperda. During summer season, the correlation analysis showed a positive correlation with maximum temperature (r= 0.675) while minimum temperature, morning humidity, evening humidity and rainfall showed a negative correlation.