Informatics Publishing Limited

A. Prabhuraj ¹, K. S. Girish ¹, Shivaleela ¹, B. V. Patil ¹

Affiliations
1 Department of Entomology, College of Agriculture, Raichur, 584101, Karnataka, IN

Abstract

A successful management strategy was developed against chickpea pod borer, Helecoverpa armigera (Hub) by integrating locally isolated entomopathogenic nematode, Heterorhabditis indica (RCR) with other entomopathogens like Helicoverpa armigera nuclear polyhedrosis virus (HaNPV) and Bacillus thuringiensis (Bt) and botanicals. Preliminary laboratory studies were conducted, to standardize the optimum dosage of nematodes required for field application, to evaluate the compatibility of nematode with entomopathogens and botanicals and their combinations. The optimum dosage of infective juveniles was standardized to third (LC₅₀ of 145 IJs/larva) and fourth (LC₅₀ of 195 IJs/larva) instars based on the concentration mortality response. Persistence study on chickpea foliage in field condition indicated that, infective juveniles along with 0.1 % glycerol survived better (80%) compared to other anti-dcssicants. In compatibility studies, though H. indica was compatible with other entomopathogens, but was susceptible to higher concentrations of aqueous leaf extracts of some selective botanicals. A series of laboratory bioassay was carried out to select best combinations of H. indica with other entomopathogens and botanicals against third and fourth instar H. armigera and these were tested in field for two consecutive years. Two year field evaluation indicated that, sequential application of H. indica + Prosopis juliflora (1 lakh IJs/I + 10%) at 50 and 75 days after sowing was superior with highest larval reduction (23.47%), minimum pod damage (11.27%) and maximum seed yield (19.24 q/h).

Keywords

Heterorhabditis indica, Helicoverpa armigera, Management, Chickpea, Botanicals, HaNPV, Entomopathogens, Mortality.

Full Text

   

A. Prabhuraj ¹, B. V. Patil ¹, K. S. Girish ¹, Shivaleela ¹

Affiliations
1 Department of Entomology, College of Agriculture, Raichur, 584 101, Karnataka, IN

Abstract

A field experiment was conducted at Agricultural College, Raichur, Karnataka to evaluate the effect of Heterorhabditis indica (RCR), an insect parasitic nematode in combination with other entomopathogens and botanicals against Helicoverpa armigera (Hübner) in chickpea ecosystem. Pooled data on per cent larval reduction after two sprays revealed that the highest reduction of 47.63 was achieved in chlorpyriphos/quinalphos (0.04/0.05%) treatment at seven days after spraying. However, sequential application of H. indica + Pa. pinnata (1.0 lakh IJs +2.5%) and H. indica + Pr. juliflora (1.0 lakh Us +10%) recorded maximum yield (1.96 and 1.83 kg/plot, respectively) with minimum pod damage (10.9 and 11.5 %, respectively). Thus there is a scope for integration of H. indica with botanicals viz. Pa. pinnata and Pr. juliflora for the effective management of chickpea pod borer.

Keywords

Bacillus thuringiensis, Heterorhabditis indica, Larval Reduction, Pongamia pinnata, Prosopis juliflora, Seed Yield.

Full Text

   

A. Prabhuraj ¹, B. V. Patil ¹, Shivaleela ¹, K. S. Girish ¹

Affiliations
1 Department of Entomology, College of Agriculture, University of Agricultural Sciences, Raichur 584 101, Karnataka, IN

Abstract

The bio-efficacy of Heterorhabditis indica Poinar in combination with Helicoverpa armigera nuclear polyhedrosis virus (HaNPV) against Helicoverpa armigera (Hiibner) was evaluated during 2002 in the laboratory. Results revealed thut combination of H. indica and HaNPV at all concentrations recorded highest mortality (100%) and were on par with alone inoculation of H. indica treatment, but significantly superior over HaNPV alone against third instar larva. Fourth instar larva suffered cent per cent mortality when inoculated with H. indica plus HaNPV at all concentrations after 48 h compared to H. indica alone (@ 200 Usl larva) which recorded 75 per cent mortality. The results indicate the synergistic effect when both the bioagents were combined against fourth instar larva.

Keywords

Entomopathogenic Nematode, HaNPV, Helicoverpa armigera, Heterorhabditis indica, Infective Juvenile.

Full Text