Seasonal Incidence of Spodoptera litura (Fab.) Infesting Groundnut with Respect to Leaf Damage

Abstract

A field experiment was conducted at Main Oilseeds Research Station, Junagadh Agricultural University, Junagadh in 2023 during the kharif season to investigate the seasonal incidence of Spodoptera litura (Fab.) infesting groundnut concerning leaf damage. The activity of the activity of S. litura began in the 31st standard meteorological week (SMW) in fourth week of July, with 5.53 per cent leaf damage initially. During the third week of August, the 34th SMW recorded the first peak of 12.97 per cent leaf damage. After a slight decrease in leaf damage, a second peak was seen in the 38th SMW, in third week of September, with 14.89 per cent leaf damage. In the following weeks, there was a decrease in the leaf damage, reaching its lowest during the 44th SMW, which fell on the fifth week of October, with 0.78 per cent leaf damage. The correlation studies showed a significant positive correlation between larval population and minimum temperature, morning relative humidity, and morning and evening vapor pressure (r = 0.613*, 0.515*, 0.637* and 0.577*, respectively).