Nitrogen Fertilizer Application in Maize and Its Impact on the Development of Chilo partellus (Lepidoptera: Pyralidae)

The current experiment was conducted to check the efficacy of different nitrogen doses on the bionomics of maize stem borer Chilo partellus (Lepidoptera: Pyrlidae) under laboratory and field conditions applied on three maize hybrids i.e., KK-8711, KWS-55 and KS-85. The results revealed that the body weight (mg) and frass weight (mg) of larvae positively correlated with nitrogen levels. There was a significant difference in weight gained by larval instars at various nitrogen applications with highest weight (0.085mg/l) at N4 (150KgN/ha) and minimum (0.078mg/l) at N0 (0KgN/ha). Identical results were observed for the frass weight of different larval instars while maximum frass weight i.e., 0.018 mg was recorded for fifth instar fed on KWS-55 with the application of N4, while minimum frass weight of fifth instar i.e., 0.012 mg fed on KK-8711 applied with N0 and N1. Significant difference for weight gained by the larvae on all three hybrids was recorded but 5 instar maximum larval weight 0.078 mg was recorded by feeding on KWS-55 while minimum 0.066 mg on KK-8711. Cumulative field data analysis showed significant difference among the average maize borer/plant at different nitrogen doses (N0-N4). Maximum number of C. partellus (2 larvae/ plant) was found on KWS-55 at (N4) while minimum (0 larvae / plant) was found on KK-8711. The results suggest that the population development of maize borer is dependent on the application of nitrogen doses.