Evaluation of natural products and biopesticides against Helicoverpa armigera (Hubner) on tomato
| dc.contributor.advisor | Verma, K. S. | |
| dc.contributor.author | Jamalli, Omid | |
| dc.date.accessioned | 2020-11-03T06:01:11Z | |
| dc.date.available | 2020-11-03T06:01:11Z | |
| dc.date.issued | 2020-08-28 | |
| dc.description.abstract | The present investigation entitled “Evaluation of natural products and biopesticides against Helicoverpa armigera (Hubner) on tomato” was undertaken during 2019-2020 in the Department of Entomology, CSK HPKV, Palampur to assess the intrinsic toxicity of different natural products and biopesticides viz. Brahmastra, Neemastra, Agniastra and Neem (azadirachtin), Beauveria bassiana, Metarhizium anisopliae, Bacillus thuringiensis var. kurstaki (Btk) and nuclear polyhedrosis virus of H. armigera (HaNPV) against the first and second instar larvae of H. armigera under laboratory conditions by the leaf dip method of bioassay. Based on LC50 values, the order of toxicity of natural products against first and second instar was observed as: Brahmastra (8.75, 11.62%) > Agniastra (9.61, 11.99%) > Neemastra (13.24, 16.21%) respectively). The LC50 values of azadirachtin (7.59, 9.85 ppm respectively) were observed against first and second instar. The feeding inhibition (FI) studies of different natural products concentration ranges from 1.25 to 20 per cent were evaluated against the third, fourth, fifth and sixth instar larvae of H. armigera. Based on FI50 values, the order of feeding inhibition of natural products tested against the third, fourth, fifth and sixth instar larvae was observed as: Brahmastra (2.92, 3.80, 4.20, 6.61%) > Agniastra (3.72, 4.55, 5.11, 7.76%) > Neemastra (3.46, 4.46, 5.28, 7.01%), respectively. While the FI50 values of azadirachtin against these instars was calculated to be 6.70, 8.83, 20.54, 27.21 ppm, respectively. Based on LC50 values, B. bassiana was found more effective against first and second instar larvae with LC50 values of 1.8x104 and 3.1x104 conidia/ ml, respectively as compared to M. anisopliae (3.0x104 and 5.8x104 conidia/ ml, respectively. Among biopesticides, the mortality was highest 66.67 and 53.33 percent, respectively to third and fourth instar larvae in case of HaNPV at concentration 3.0x106 PIBs/ ml after 120 h of treatment. The mortality to third and fourth instar larvae was recorded 63.33 and 56.66 per cent, respectively with B. thuringiensis var. kurstaki at concentration 7.5x106 spores/ ml after 120 h of treatment. Interaction effect of Brahmastra with different biopesticides was studied against third instar larvae of H. armigera and maximum additive effect was observed between Brahmastra and B. bassiana with 2.61 χ2 value. | en_US |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810154226 | |
| dc.keywords | biopesticides, tomato, brahmastra, neemastra, agniastra | en_US |
| dc.language.iso | English | en_US |
| dc.pages | 82 | en_US |
| dc.publisher | CSKHPKV. Palampur | en_US |
| dc.sub | Entomology | en_US |
| dc.theme | crop protection | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Evaluation of natural products and biopesticides against Helicoverpa armigera (Hubner) on tomato | en_US |
| dc.type | Thesis | en_US |