Effect of Certain Plant Oils on the Viability and Pathogenicity of Bacillus thuringiensis Ber. on Lepidopteran Pest Complex of Cauliflower
KrishiKosh
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Title |
Effect of Certain Plant Oils on the Viability and Pathogenicity of Bacillus thuringiensis Ber. on Lepidopteran Pest Complex of Cauliflower
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Creator |
Rajesh Babu, G
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Contributor |
Krishnayya, P. V
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Subject |
Effect, Certain, Plant, Oils, Viability, Pathogenicity, Bacillus, thuringiensis, Ber, Lepidopteran, Pest, Complex, Cauliflower
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Description |
The present investigation on the ‘Effect of certain plant oils on the viability and pathogenicity of Bacillus thuringiensis Ber. on lepidopteran pest complex of Cauliflower’ was taken up under laboratory and field conditions at Agricultural College, Bapatla, during rabi 2004-05. The laboratory studies were carried out using Bacillus thuringiensis var. kurstaki Kurstak (B.t.k.; Delfin WG) in combination with plant oils (neem oil, Azadirachta indica A. Juss., karanj oil, Pongamia glabra Vent.; cotton seed oil, Gossypium hirsutum L.; citronella oil, Cymbopogan winterianus Stapf. and sesamum oil, Sesamum indicum L.) against third instar larvae of Spodoptera litura (Fab.). Among all the treatments tested B.t.k. 0.2% + neem oil 5% recorded the highest larval mortality (80.00%), feeding inhibition (79.95%), mean larval weight reduction (29.98%), pupation (18.33%), normal pupae (13.33%), normal adults (11.66%), pupal weight reduction (30.98%), prolonged larval and pupal periods (11.00 and 12.00 days, respectively) over untreated check. The other combinations of plant oils with B.t.k. were also effective in resulting higher larval mortality (70.00 to 55.00%), feeding inhibition (67.05 to 32.44%), mean larval weight reduction (28.62 to 21.49%), pupal weight reduction (24.29 to 12.38%), normal pupae (18.33 to 35.00%), normal adults (18.33 to 31.66%), prolonged larval and pupal periods (10.33 to 9.33, 10.66 to 10.33, respectively) compared to untreated check. The treatments that proved efficacious in the laboratory were consistently effective in the field also. The results indicated that among the combinations of B.t.k. with plant oils, B.t.k. 0.2% + neem oil 5% recorded the highest per cent reduction of the lepidopteran pests viz., Spodoptera litura (Fab.) (57.51%), Crocidolomia binotalis Zeller (51.74%) and Plutella xylostella (L.) (52.74%) with the highest curd yield of 4886.66 Kg ha-1. The other combination treatments B.t.k. 0.2% + citronella oil 5%, B.t.k. 0.2% + karanj oil 5%, B.t.k. 0.2% + cotton seed oil 5% and B.t.k. 0.2% + sesamum oil 5% recorded significantly higher per cent reduction of the larvae over B.t.k. 0.2% and untreated check (S. litura 53.9, 49.50, 48.89 and 45.51%, respectively; C. binotalis 44.90, 38.28, 38.69 and 38.09%, respectively and P. xylostella 48.06, 38.07, 38.28 and 34.30%, respectively) with significantly higher curd yields (4440, 4000, 3886.66 and 3833.33 Kg ha-1, respectively). From the cost benefit ratio point of view, B.t.k. 0.2% + neem oil 5% (1: 4.60), followed by B.t.k. 0.2% + citronella oil 5% (1 : 2.92), B.t.k. 0.2% + karanj oil 5% (1 : 2.40) were found more economical. The field persistent pathogenicity of B.t.k. in combination with plant oils against third instar larvae of S. litura revealed that for the first, three and five days after application B.t.k. 0.2% + neem oil 5% resulted significantly the highest larval mortality (77.54 to 65.00%), whereas at seven and nine days after application, B.t.k. 0.2% + cotton seed oil 5% recorded significantly the highest larval mortality (40.00 and 13.33%, respectively). The combinations of B.t.k. with plant oils tested for viability revealed that B.t.k.0.2% + cotton seed oil 5% recorded maximum number of viable spores at three, five, seven and nine days after application that ranged from 35.33 to 16.33 x 104, when compared to other B.t.k. combinations with neem oil 5%, citronella oil 5%, sesamum oil 5% and karanj oil 5% (30 to 7.33 x 104) indicated better U.V. protectant activity of cotton seed oil. |
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Date |
2016-08-20T10:47:56Z
2016-08-20T10:47:56Z 2005 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/73118
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Language |
en
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Relation |
D7644;
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Format |
application/pdf
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Publisher |
ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD
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