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Subject: Entomology × Author: Sarvesh Kumar Singh × End date: 2009 × Start date: 2006 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Field evaluation of methanolic plant extracts against bollworms in cotton
    (CCSHAU, 2006) Sarvesh Kumar Singh; Ram Singh
    Methanolic plant extracts neem, bakain, and karanj and ginger at 2.5, 5.0 and 7.5 per cent were sprayed (5 sprays at 8 days interval) against bollworms in hirsutum cotton variety H-1117 at Research area, Dept. of Entomology, CCS Haryana Agricultural University, Hisar, Haryana. Higher concentration (7.5%) of neem, bakain and karanj caused significant incidence of bollworms in shed squares (13.42 – 17.01%), shed bolls (13.89 – 18.58%), intact squares (14.00 – 22.66%) and intact green bolls (16.00 – 23.39%) on 7th day after fifth spray. The incidence was on par with nimbecidine but significantly higher than control. Reduction in larval population followed similar trend.Ginger was found inferior to neem, bakain, karanj and nimbecidine but better than control in respect of bollworms incidence. Neem (5.0%) also showed considerable adverse impact on bollworms incidence. Earias spp. dominated the bollworm complex.In case of field incidence, larval population of bollworms in open bolls on locule basis at 7.5 per cent concentration was minimum (5.29%) in neem, followed by (6.63%) in bakain and (7.79%) in karanj, which was on par with nimbecidine (7.69%). Ginger manifested significantly higher incidence (14.27 – 16.06%) than nimbecidine at all doses. Consumption index (6.38 – 6.56), growth rate (0.613 – 0.626), efficiency of conversion of ingested food (9.34 – 9.82 %), approximate digestibility (65.66 – 67.91 %) and efficiency of conversion of digested food (10.25 – 10.76 %) of E. vittella larvae were adversely affected when fed on bolls field sprayed with 7.5 per cent methanolic extracts of neem, bakain and karanj. These indices were on par with nimbecidine but significantly adversely affected in comparison to control. Similar trend was observed in case of H. armigera. Ginger did not adversely affect consumption – utilization indices of both the pests. Various biological parameters of Earias vittella were significantly adversely affected when the larvae were allowed to feed on young to medium aged bolls collected from plants sprayed with methanolic extracts. Larval period (12.70 – 13.50 days), larval survival (50.20 –54.42), larval weight (48.09 – 52.42 mg), pupal period (10.60 – 11.70 days), pupal weight (40.65 – 42.54 mg), adult emergence (61.40 – 65.40 %) and fecundity (54.70 – 59.10 eggs/female) were adversely affected in 7.5 per cent concentration of neem, bakain and karanj as compared to control. Feeding on ginger had no adverse effects on various biological parameters, which was on par with control. Neem at 5.0 and 7.5 per cent and bakain and karanj at 7.5 per cent each were as effective as nimbecidine.Yield of seed cotton 7.5% conc. of neem (18.17 q/ha), bakain (17.42%) and karanj (17.33 q/ha) was on par with nimbecidine (16.92 q/ha). Ginger proved inferior to all concentrations.