Effect of nitrogen levels on the incidence of stalk borer (Chilo auricilius Dudgeon) in sugarcane varieties

The present investigations were carried out to study the influence of nitrogen levels on the incidence of stalk borer, Chilo auricilius Dudgeon in sugarcane varieties. The infestation of stalk borer increased significantly with the increase in dose of nitrogen. It increased from an average of 16% at 60 kg N/ha to 22.8% at 240 kg N/ha. The per cent increase in infestation of stalk borer in different sugarcane varieties by 240 kg N over 60 kg N/ha was found to be 28.6% in BO 131, 28.9% in BO 128, 39.9% in BO 133, 40.4% in CoP 9204, 40.6% in BO 129 and 66.8% in BO 132. At higher level of nitrogen application variety BO128 (19.92%) was found more tolerant to stalk borer.