Field Evaluation of Native Nucleopolyhedrovirus for the Management of Sunflower Head borer, Helicoverpa armigera (Hiibner)

The efficacy of two weekly sprays of a native isolate (PAUI) of HaNPV against the sunflower head borer, Helicoverpa armigera was assessed at two dosages viz., 250 LE/ha and 375 LE/ha in a replicated field trial. The lower dosage was ineffective in reducing the larval population and % head damage by the pest. The higher dosage of HaNPV with a larval population of 1.0 larva/l0 plants was at par with the standard insecticide (carbaryl 1.0 kg a.i./ha) treatment with 1.l6 larva/10 plants. The highest yield of 13.5 q/ha was recorded with the higher dosage of HaNPV which was, however, at par with carbaryl (12.4 q/ha). On the otherhand, lower dosage of HaNPV with a yield of 8.8 q/ha was at par with control (6.3 q/ha).