Effect of Temparature on Growth& development of Helicoverpa on Tomato crop
KrishiKosh
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Title |
Effect of Temparature on Growth& development of Helicoverpa on Tomato crop
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Creator |
Dalal, Pradeep Kumar
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Contributor |
Ramesh, Arora
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Subject |
Entomology
tomato crop Plant Pathology |
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Description |
The studies on effect of different alternating temperatures on biology, life table parameters, food consumption and nutritional indices of Helicoverpa armigera (Hubner) on tomato crop were conducted during 2013-14. The duration of H. armigera immature stages viz. egg, larva and pupa decreased with increase of alternating temperature from 25:10 oC to 30:16 oC, thus resulting in shorter life cycle at higher temperatures. The total degree days accumulated for the development of egg stage, larval stage, pupal stage and total immature stages were estimated to be 42.48, 533.08, 154.88 and 692.18 oD, respectively. The fecundity of females varied from 625.10±65.52 to 328.60±43.52 eggs per female at different alternating temperatures. The highest intrinsic rate of increase (rm) of H. armigera was reported at 30:10 oC (0.0488) closely followed by 25:16 oC (0.0485) and 25:13 oC (0.0423). Low net reproductive rates (R0) of 7.25 to 22.31 in different treatments indicated the unsuitability of tomato genotype US-8502 as host for H. armigera. Low larval survival of H. armigera from 10.00± 2.52 to 19.00±3.42 per cent suggested that tomato genotype US-8502 was an unsuitable host. The food consumption by H. armigera larvae varied from 0.113±0.009 to 0.234±0.007, 0.136±0.010 to 0.428±0.003, 2.209±0.046 to 2.990±0.008 and 2.457±0.048 to 3.545±0.021 g/larva in third, fourth and fifth instars and whole larval period, respectively. The rise in mean minimum and maximum temperatures up to 30:10 oC resulted in increased food consumption by H. armigera larvae. The share of food consumption by fifth instar larvae was ≥ 80 per cent of total food consumption by H. armigera larvae in all the treatments. Nutritional indices for total larval duration of H. armigera such as consumption Index (CI) rose from 0.929±0.020 to 1.495±0.014 approximate digestibility (AD) rose from 8.675±1.079 to 46.298±0.209 per cent while the efficiency of conversion of ingested food (ECI) declined from 14.993±0.797 to 9.371±0.256 per cent with increase in temperature. The relative growth rate (RGR) varied from 0.1390.002 to 0.1740.003 at different alternating temreaptures. The rise in mean minimum and maximum temperatures up to 30:10 oC resulted in increased RGR of H. armigera larvae.
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Date |
2016-09-14T14:38:24Z
2016-09-14T14:38:24Z 2014 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/76714
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Language |
en
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Format |
application/pdf
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Publisher |
Punjab Agricultural University, Ludhiana
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