Vol. 8, Special Issue 9, Part M (2024)

With a view to know the effect of weather parameters on activity of spotted pod borer infesting green gram, an experiment was carried out on population dynamics of spotted pod borer in green gram under field condition during summer, 2021 at Pulse Research Station, Junagadh Agricultural University, Junagadh. The incidence of spotted pod borer, M. testulalis (Geyer) commenced from the last week of March (vegetative growth stage) and continued till the second week of May (up to crop maturity). The pest population commenced on green gram during the 13^th SMW with 0.40 larval population and 12.46 percent pod damage during the 14^th SMW. Further, it was found that after initiation of pest population and percent of pod damage increased rapidly. During SMW 14 and 15, the population of M. testulalis was 0.84 and 1.58 larva per plant with 12.46 and 14.26 percent pod damage, respectively. The population increased very fast during 16^th SMW and reach a peak with 3.54 larvae per plant and 32.68 percent pod damage. After reaching the peak, the pest population and pod incidence decline continuously during each week. The pest infestation was initiated during the vegetative phase of green gram i.e., 3^rd week after sowing. The larval population of the M. testulalis was recorded to be 1.58 to 3.54 larvae per plant during the flowering, pod formation and pod development stage of green gram i.e., 5^th to 8^th weeks after sowing. The pest population declined quickly during pod maturity in green gram. Spotted pod borer population had significant positive correlation with minimum temperature (r = 0.759* and r = 0.683*, respectively). However, the maximum temperature (r = 0.491), morning relative humidity (r = 0.658), evening relative humidity (r = 0.339) and wind speed (r = 0.310) had non-significant positive correlation. In pod damage non-significant positive correlation with maximum temperature (r = 0.488), morning relative humidity (r = 0.560), evening relative humidity (r = 0.299) and wind speed (r = 0.324) was observed. However, the pest population showed significant negative correlation with bright sunshine (r = -0.670*) and non-significant negative correlation with evaporation (r = -0.252).