Biorational approaches for the management of fruit borer, Helicoverpa armigera (Hübner) in bell pepper
KrishiKosh
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Title |
Biorational approaches for the management of fruit borer, Helicoverpa armigera (Hübner) in bell pepper
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Creator |
Nazatinder Singh
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Contributor |
Aggarwal, Naveen
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Subject |
Entomology
bell pepper Plant Pathology |
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Description |
The studies on biorational approaches for the management of fruit borer, Helicoverpa armigera (Hübner) in bell pepper were conducted in Biological Control Laboratory and at Entomological Research Farm, Department of Entomology, Punjab Agricultural University, Ludhiana during 2012 and 2013. Toxicity and efficacy of six biorational insecticides against this pest and their impact on natural enemy‟s fauna in bell pepper ecosystem was evaluated. In leaf dip bioassay, on the basis of LC50 values against 3rd instar larvae of H. armigera, the order of toxicity of tested insecticides was emamectin benzoate > azadirachtin > spinosad > B. thuringiensis > B. bassiana > HaNPV. The respective LC50 values for these insecticides were 0.00015, 0.00016, 0.00143, 0.00144, 0.00277 per cent and 2.39x105 PIB ml-1, respectively. However, field doses calculated on the basis of LC50 were recorded with highest cumulative mortality of 3rd instar larvae in emamectin benzoate 5 SG (60.51%) and spinosad 45 SC (56.24%). For per cent pupation of surviving larvae, emamectin benzoate (22.37%) and spinosad (26.66%) showed significantly lowest pupation. Similar pattern was observed in pupal weight and healthy pupae. Maximum adult emergence was in control (90.00%) followed by HaNPV (37.24%). Azadirachtin 1 EC had the latent effect on hatchability of eggs laid by recovered adults by significantly reducing egg hatching. In ovicidal tests, lowest hatchability of eggs 72 h after treatment was recorded with spinosad (23.66%) and emamectin benzoate (30.53%). Under field conditions, spinosad (29.67 plant-1) and emamectin benzoate (27.67 plant-1) were most efficient in reducing larval population and per cent fruit infestation with highest number of healthy fruits in these treatments. The highest marketable fruit yields and B: C ratio was again recorded in plots treated with spinosad (44.86 t ha-1; 1:2.78) and emamectin benzoate (42.96 t ha-1; 1:2.69). The different biorational pesticides had little effect on population of coccinellid beetles (0.34 to 0.50 plant-1) and chrysopids (0.54 to 0.74 plant-1). Studies on disruptive influence of different biopesticides on T. chilonis revealed that emamectin benzoate @ 0.60 g L-1 affected the adult emergence (77.41% emergence) most followed by spinosad @ 0.64 ml L-1 (75.80% emergence) and azadirachtin @ 3.20 ml L1 (81.15%). HaNPV was least disruptive to adult emergence (87.25%) followed by B. bassiana (87.10%) and B. thuringiensis (85.50%) |
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Date |
2016-09-14T15:24:15Z
2016-09-14T15:24:15Z 2014 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/76744
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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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