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Combination effect of Bacillus thuringiensis Ber. with certain botanicals against major insect pests of sunflower

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Title Combination effect of Bacillus thuringiensis Ber. with certain botanicals against major insect pests of sunflower
 
Creator RAJASEKHAR, Y
 
Contributor KRISHNAYYA, P.V
 
Subject Combination, effect, Bacillus, thuringiensis, Ber, certain, botanicals, against, major, insect, pests, sunflower
 
Description The present investigation ‘Combination effect of Bacillus thuringiensis Ber.
with certain botanicals against major insect pests of sunflower’ was taken up under
field and laboratory conditions at Agricultural College, Bapatla, during rabi 2003-
04. The field investigation was carried out using Bacillus thuringiensis var. kurstaki
(B.t.k.; Dipel 8 L) and botanicals [neem seed kernel extract (NSKE), Azadirachta
indica A. Juss; sweet-flag rhizome extract(SFRE), Acorus calamus L.; pungam seed
extract (PSE), Pongamia glabra Vent. and annona seed extract (ASE), Annona
squamosa L.] alone and in combination against major lepidopteran pests of
sunflower viz., Spilosoma obliqua (Walker), Spodoptera litura (Fab.) and
Helicoverpa armigera (Hub.). Larval incidence of the pests was regularly
monitored on alternate days and the insecticidal treatments were given as sprays
twice at 55 and 66 days after sowing.
The results indicated that among the eleven treatments tested endosulfan
0.07%, the standard check recorded the highest per cent reduction of larval
population (S. obliqua, 66.34; S. litura, 58.87 and H. armigera 56.08) and the
highest seed yield of 1420.00 kg ha-1. Combination treatments viz., B.t.k. 0.1% +
NSKE 2.5%, B.t.k. 0.1% + SFRE 2.5%, B.t.k. 0.1% + ASE 2.5% and B.t.k. 0.1% +
PSE 2.5% recorded significantly higher per cent reduction of the larval population
(S. obliqua: 58.01, 52.18, 46.76 and 44.58, respectively; S. litura: 55.53, 50.04,
44.80 and 43.44, respectively and H. armigera: 53.18, 47.11, 43.43 and 41.07,
respectively) with significantly superior seed yield (1593.34, 1520.00, 1366.67 and
1326.67 kg ha-1, respectively). The corresponding per cent larval population
reduction in the individual treatments B.t.k. 0.2% and 5.0% of NSKE, SFRE, ASE
and PSE was moderate ( S. obliqua: 43.15, 41.24, 36.69, 31.01 and 28.60,
respectively; S. litura: 39.09, 38.90, 33.57, 28.29 and 25.83, respectively and
H. armigera: 37.24, 36.62, 31.52, 26.83 and 24.51, respectively) with seed yield of
1456.67, 1200.00, 1153.33, 1120.00 and 1033.33 kg ha-1, respectively.
From the point of cost benefit ratio, the most economical treatments were
endosulfan 0.07%, the standard check (1: 3.85), NSKE 5.0% (1: 2.86), ASE 5.0%
(1: 2.52) and B.t.k. 0.1% + NSKE 2.5% (1: 2.17).
The treatments that proved efficacious in the field were consistently
effective in the laboratory against S. litura, resulting in higher larval mortality
( 93.33 to 56.67%), feeding inhibition ( 90.53 to 41.84%), weight gain (135.11 to
235.88 mg), pupation (6.67 to 43.33%), pupal weight reduction (36.36 to 09.09%),
normal pupae (3.33 to 34.66%) and normal adult emergence (00.00 to 24.07%) and
longer larval period (10.3 to 8.3 d) and pupal period (12.0 to 10.0).
The botanicals tested individually at 0.63, 1.25, 2.5 and 5.0% concentrations
against S. litura were found moderately effective and their efficacy was
concentration dependent.
The treatment B.t.k. when it was alone recorded significantly the highest
harvest of spores and cells ml-1 (253 x 1010 to 173 x1010) from 0 to 30 days after
incubation and inoculation on nutrient agar medium. But harvest of spores and cells
of B.t.k. was relatively poor when B.t.k. was mixed and inoculated with the
botanicals for varying intervals of time. However, among the combinations, B.t.k.
with NSKE at all the concentrations recorded higher harvest of spores and cells ml-1
(241.7 x 10 10 - 215 x 1010 to 156 x 1010 - 22 x1010 ) at 0.0 to 30.0 days after
preparation and incubation. It was followed by B.t.k.+ SFRE (237 x 1010 - 208 x
1010 to 147 x 1010 - 17 x 1010), B.t.k. + ASE (247.6 x 1010 - 213 x 1010 to 142 x
1010 - 12 x1010) and B.t.k. + PSE (249 x 1010 - 217 x 1010 to 137 x 1010 - 10.6 x
1010). These results indicated PSE has higher antibacterial effect compared to the
other botanicals viz., ASE, SFRE and NSKE.
 
Date 2016-08-20T10:29:58Z
2016-08-20T10:29:58Z
2004
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/73107
 
Language en
 
Relation D7634;
 
Format application/pdf
 
Publisher ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD