Management of chickpea pod borer, Helicoverpa armigera (Hubner) through Nuclear Polyhedral Virus isolates

摘要

Investigations were carried out on Helicoverpa armigera Nuclear Polyhedrosis Virus (HaNPV) isolates collected from different parts of India to study their genetic diversity through molecular characterization and their assessment in the IPM of Helicoverpa armigera on chickpea under field conditions. Variations were found in the DNA profiling of different HaNPV isolates. The similarity matrix relating the different isolates showed similarity co-efficients ranging from 0.38 to 0.82. The highest genetic similarity index of 0.82 was seen between the isolates from Raichur and Guntur followed by 0.77 between the isolates from Coimbatore and Raichur. Field evaluation of different HaNPV isolates against H. armigera in the chickpea ecosystem at the Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, Karnataka for 2 years revealed that the performance of the Gulbarga and Coimbatore isolates was better than that of others in terms of their ability to cause greater larval mortality of H. armigera with a greater yield of chickpea. The Incremental Benefit Cost Ratio was highest with the Gulbarga (2.88) and Coimbatore (2.83) isolates, followed by the Dharwad isolate (2.39).