Studies on bollworm complex of cotton and their management
KrishiKosh
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Title |
Studies on bollworm complex of cotton and their management
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Creator |
B. K, Shivanna
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Contributor |
N. G, Kumar
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Subject |
cotton, planting, diseases, animal developmental stages, yields, genotypes, insecticides, sowing, inorganic acid salts, crops
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Description |
Investigations on bollworm complex of cotton and their management were carried out at Zonal Agricultural Research Station, Navile, Shimoga, during 2007-2009. Studies on population dynamics of bollworms through pheromone traps comprises pink bollworm (31.46%), american bollworm (29.50%), spiny bollworm (21.00%) and spotted bollworm (18.01%) in hierarchy with peak collections in 6 - 9th, 23rd and 38 - 46th standard weeks. Early sowing of (April to June month) DCH - 32 cotton exhibited minimum larval population, (squares and bolls), square and green boll damage, shed fruiting bodies with maximum yield and yield attributing parameters compared to July and August sown crop. Screening genotypes against bollworms indicated that the hirsutum (Abadhita and Sahana) and arboreum (AK - 235 and DLSa - 17) varieties suffered less from bollworms larval population (squares and bolls), square and green boll damage, shed fruiting bodies with maximum yield and yield attributing parameters than herbaceum and hybrids. Foliar application of thiodicarb, spinosad, novaluron and indoxacarb alone at 60 dyas after sowing with an interval of 15 days resulted in less larval population (squares and bolls), square and green boll damage, shed fruiting bodies with maximum yield and yield attributing parameters than botanicals (NSKE 5%) / microbial (Bt) or alternated sprays with synthetic or microbial groups or botanicals. However, botanicals, microbial and their derivatives recorded higher population of predators viz., Coccinellids, chrysopids and syrphids than any other treatments. Significantly maximum seed cotton yield was recorded in spinosad (2123.06 kg/ha) followed by thiodicarb (2012.77 Kg/ha), emamectin benzoate (1453.52 Kg/ha), novaluron (1908.82 Kg/ha) and indoxacarb alone (1891.58 Kg/ha) than untreated control (475.00 Kg/ha). The highest B/C ratio was recorded in thiodicarb (1:10.05), alternated spray application of lamba cyhalothrin 5 EC – endosulfan 35 EC – chlorpyriphos 20 EC – thiodicarb 75 WP – thiodicarb 75 (1:9.83) and endosulfan (1:8.22). Interestingly additional yield over control was high in spinosad (1148.06 Kg/ha) where the cost of additional treatment (Rs.14716.79) was also high in this treatment. |
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Date |
2016-05-26T09:53:20Z
2016-05-26T09:53:20Z 2011-11-18 |
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Type |
Thesis
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Identifier |
Th-9885
http://krishikosh.egranth.ac.in/handle/1/66320 |
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Language |
en
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Format |
application/pdf
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Publisher |
University of Agricultural Sciences, Bengaluru
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