Thumbnail Image

Theses

Browse

20191
Reset filters
Subject: Agricultural Entomology × Author: Anju Viswanathan, K × Author: KAU × End date: 2019 × Start date: 2019 × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    Insecticide mixtures for the management sucking pest complex in chilli
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 2019) Anju Viswanathan, K; KAU; Ambily Paul
    A study on "Insecticide mixtures for the management of sucking pest complex in chilli" was undertaken at College of Agriculture, Vellayani and farmers field at Kalliyoor during 2018 October to 2019 January. The objectives were to evaluate the efficacy of insecticide mixtures against sucking pest complex in chilli and to study the pesticide residues in chilli fruits. Major pests recorded during the study include white fly, Aleurothrixus trachoides Back, thrips, Scirtothrips dorsalis Hoods, mite, Polyphagotarsonemus latus Banks and aphid. Aphis gossypii Glover. The laboratory experiment was laid out in CRD to study the efficacy of insecticide mixmres viz., thiamethoxam 12.6 % + lambda cyhalothrin 9.5 % ZC @ 33 + 15.75 g a.i ha"', beta cyfluthrin 8.91% + imidacloprid 19.81 % CD @ 15.75 + 36.75 g a.i ha"', flubendiamide 19.92% + thiacloprid 19.92 % SC @ 48 + 48 g a.i ha"', fipronil 40% + imidacloprid 40% WG @ 175 + 175 g a.i ha"', spiromesifen 22.9% SC + thiamethoxam 25 % WG (hand mixed) (1:1) @ 96 + 50 g a.i ha"' along with two positive controls T6- spiromesifen 22.9% SC @ 96 g a.i ha"'and thiamethoxam 25 % WG @ 50 g a.i ha"' against pests of chilli. Results of the laboratory screening revealed that fipronil 40% + imidacloprid 40% WG @ 175 + 175 g a.i ha"' was the effective treatment in managing all sucking pests, in which whiteflies, thrips, mites and aphids were not present on seventh day after spraying. This was followed by beta cyfluthrin 8.91% + imidacloprid 19.81 % OD @ 15.75 + 36.75 g a.i ha"' and thiamethoxam 25 % WG @ 50 g a.i ha"'. No mite population was observed in spiromesifen 22.9 SC @ 96 g a.i ha"' treated plants from second day after application. The insecticide mixtures / insecticides selected for the field studies were fipronil 40% + imidacloprid 40% WG @ 175 + 175 g a.i ha"', beta cyfluthrin 8.91% + imidacloprid 19.81 % OD @ 15.75 + 36.75 g a.i ha"', spiromesifen 22.9% SC @ 96 g a.i ha"' and thiamethoxam 25 % WG @ 50 g a.i ha"' by considering their effectiveness in managing sucking pests under laboratory conditions. The results of field evaluation revealed that less incidence of whiteflies was observed on fipronil 40% + imidacloprid 40% WG @ 175 + 175 g a.i ha"' (0.43 leaf') treated plants on seventh day after spraying followed by beta cyfluthrin 8.91% + imidacloprid 19.81 % OD @ 15.75 + 36.75 g a.i ha-'(0.60 leaf ') and thiamethoxam 25 % WG @ 50 g a.i ha"' (2.23 leaf'). No population of thrips was observed in plants treated with fipronil 40% + imidacloprid 40% WG @ 175 + 175 g a.i ha"' on tenth day after spraying followed by beta cyfluthrin 8.91% + imidacloprid 19.81 % OD @ 15.75 + 36.75 g a.i ha-'(1.30 leaf'). Spiromesifen 22.9% SC @ 96 g a.i ha"' showed superiority over other treatments, in checking the population of mites, P. latus and no mites were observed on plants treated with spiromesifen 22.9% SC @ 96 g a.i ha"' from seventh day after spraying followed by fipronil 40% + imidacloprid 40% WG @ 175 + 175 g a.i ha"' (1.63 leaf') and beta cyfluthrin 8.91% + imidacloprid 19.81 % OD @ 15.75 + 36.75 g a.i ha"' (2.30 leaf'). Spiromesifen 22.9% SC @ 96 g a.i ha"' found to be safe to natural enemies as compared to other treatments. Number of chilli aphids, A. gossypii was lower in fipronil 40% + imidacloprid 40% WG @ 175 + 175 g a.i ha"' (0.52 leaf' ) treated plants followed by beta cyfluthrin 8.91% + imidacloprid 19.81 % OD @ 15.75 + 36.75 g a.i ha"'(0.60 leaf') after seven days of spraying. Dissipation of residues of these effective insecticides was studied by analysing the chilli fruits collected at 0, 1, 3, 5, 7, 10, 15 and 30 days after treatment and the results showed that in fipronil 40% + imidacloprid 40% WG sprayed fruit, fipronil dissipated within two hours of spraying and imidacloprid dissipated in three days. Beta cyfluthrin £uid imidacloprid in beta cyfluthrin 8.91% + imidacloprid 19.81 % OD mixture dissipated within fifteen and seven days respectively. The risk assessment study also proved the safety of the insecticide mixtures. The results of the present study revealed that spraying of fipronil 40% + imidacloprid 40% WG @ 175 + 175 g a.i ha"' or beta cyfluthrin 8.91% + imidacloprid 19.81 % OD @ 15.75 + 36.75 g a.i ha"' could effectively manage pest complex in chilli with minimal risk to end users.