EVALUATION OF CHITIN SYNTHESIS INHIBITORS ON LEPIDOPTERAN PESTS OF GROUNDNUT
KrishiKosh
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Title |
EVALUATION OF CHITIN SYNTHESIS INHIBITORS ON LEPIDOPTERAN PESTS OF GROUNDNUT
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Creator |
SAILAJA, G
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Contributor |
RAJENDRA PRASAD, P
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Subject |
chitin synthesis inhibitors, insecticides, animal developmental stages, biological phenomena, chitin, application methods, eggs, concentrates, sexual reproduction, biological development
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Description |
The present studies on “Evaluation of chitin synthesis inhibitors on lepidopteran pests of groundnut” were carried out at S.V. Agricultural College, Tirupati during 2011-12. The effect of chitin synthesis inhibitors against S. litura and A. modicella was evaluated under laboratory and field conditions. The five chitin synthesis inhibitors viz., Diflubenzuron (Dimiln 25WP), Novaluron (Rimon 10EC), Lufenuron (Match 5EC), Flufenoxuron (Cascade 10DS) and Buprofezin (Apple 25WP) were used in the present investigation each at three different concentrations i.e. at 0.005 per cent, 0.01 per cent and 0.02 per cent. The chitin synthesis inhibitors were evaluated against eggs, larvae, pupae and adults stages of S. litura and A. modicella and studied the morphological changes occurred at different stages. The mean per cent chitin inhibition deposition was estimated in the final instar larvae of S. litura and A. modicella. The treated eggs of S. litura and A. modicella turned pale black and were shrivelled and reduced in size. The larvae treated with chitin synthesis inhibitors became sluggish, stopped feeding and consequently reduced in size. The apolysed larvae could be seen moving within intact exuviae and they could not split the exuviae. The treated pupae were reduced in size and shrunken and the adults emerged from such pupae were deformed with crippled and wrinkled wings, reduced body size and reduced antennae. xii The mean per cent inhibition of chitin deposition in the final instar larvae of S. litura and A. modicella was highest in treatment novaluron 0.02 per cent. The per cent inhibition increased with increase in concentration. Among all the treatments, minimum per cent egg hatching of S. litura and A. modicella was recorded in novaluron 0.02 per cent treatment in all the three methods of application. Among the three methods, dipping method was found to be superior followed by topical application and surface treatment methods. Highest per cent larval mortality was observed in ingestion method, followed by larval dip and topical application methods in both S. litura and A. modicella larvae. The early instar larvae were more susceptible than later instars and per cent larval mortality was more at higher concentrations than at lower concentrations. Pupal dipping in different concentrations resulted in pupal mortality at higher concentrations and malformed adults at lower concentrations. Normal adult emergence decreased with increase in concentration of chemicals. The mean ovipostion of S. litura and A. modicella was highly reduced in treatment “novaluron 0.02 per cent”. The rate of inhibition of egg laying increased with increase in concentration of chemical. The longevity of both male and female adults of S. litura and A. modicella was greatly reduced at higher concentration than at lower concentration of chemicals. The field results revealed that novaluron @75 g a.i ha-1 was found to be continuously effective in reducing the populations of S. litura and A. modicella. The overall efficacy in offering reduction over pretreatment counts revealed that novaluron was effective in bringing down the population which was followed by thiodicarb, lufenuron and flufenoxuron. The treatment with novaluron @75 g a.i ha-1 recorded highest pod yield of 1433 kg ha-1 over untreated check with 905 kg ha-1 followed by the treatments thiodicarb @ 300 g a.i ha-1 and lufenuron@75 g a.i ha-1. |
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Date |
2016-06-16T15:25:02Z
2016-06-16T15:25:02Z 2012 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/67485
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Language |
en
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Relation |
D9344;
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Format |
application/pdf
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Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
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