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Subject: Entomology × Author: Bhupender Singh × End date: 2007 × Start date: 2000 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Evaluation of management practices against bollworms and their effect on sucking pests in cotton
    (CCSHAU, 2005) Bhupender Singh; Saini, R.K.
    Different pest management practices, namely, date of sowing, Trichogramma chilonis release, intercropping with sesame, use of botanical pesticides like neem, and chemical insecticides, were evaluated alone and in combinations against bollworms of cotton during Kharif, 2004 at the Research Farm of Department of Entomology, CCS Haryana Agricultural University, Hisar. These practices were tested on cotton variety H-1117 in plot size of 48m2 keeping three replications and their impact on population of sucking insect pests (i.e. leafhopper, whitefly and aphid) was also assessed. The studies indicated that all management practices, either alone or in combinations, provided significantly better control of bollworms than the control both on the basis of damage in green fruiting bodies as well as open bolls. Minimum bollworms incidence was recorded in treatments where insecticides were used either alone or in combination with other management practices. Combined use of different management practices other than chemical insecticides did not prove as effective as chemical insecticides in controlling bollworms and increasing the yield of seed cotton. However, these practices offered significantly greater reduction in bollworms damage over the control. Further, their integration with insecticides resulted in about 57 per cent reduction in insecticides sprays. Combined use of different practices, i.e. intercropping of cotton with sesame + neem + Trichogramma release significantly reduced bollworms damage than when these practices were used alone. There was 31.8, 21.5 and 4.1 per cent parasitization of Helicoverpa armigera eggs by Trichogramma in treatments having intercropping with sesame, weekly release of Trichogramma and control, respectively. Overall bollworms damage in green fruiting bodies was highest (19.6%) in early sown, followed by that in normal sown (14.65%) and late sown (9.61%) crop. On the other hand, bollworms incidence in open bolls (on locule basis) was lower (41.1%) in early sown than the late sown (49.6%) crop. Wider row to row spacing of one meter was no better than 67.5 cm spacing in reducing bollworms damage under late sown conditions.