Record Details

Efficacy of new formulations of Bacillus thuringiensis var. kurstaki against Helicoverpa armigera (Hubner)

KrishiKosh

View Archive Info
 
 
Field Value
 
Title Efficacy of new formulations of Bacillus thuringiensis var. kurstaki against Helicoverpa armigera (Hubner)
 
Creator DINESH SWAMI
 
Contributor Bishwajeet Paul
 
Subject biological phenomena, economic systems, marketing, sets, selection, sampling, sexual reproduction, stimulants, manpower, social sciences
 
Description t-8047
Bioassays were conducted under laboratory conditions to assess the efficacy
of new wettable powder (WP) formulations of Bacillus thuringiensis var. kurstaki (HD-
1) against IIIrd instar larvae of Helicoverpa armigera (Hubner). Sixteen new WP
formulations of B. thuringiensis var. kurstaki (HD-1) were developed and relative
efficacy was calculated on the basis of LC50 values. The results indicated that LC50
values of recipe-2 (0.032%), recipe-7 (0.018%), recipe-9 (0.030%) and recipe-15
(0.015%) were highly effective against IIIrd instar larvae of H. armigera in comparison
to Dipel® 8L (0.037%) and Biolep® (0.046%) (Commercial formulation of B.
thuringiensis var. kurstaki). On the basis of laboratory performance, recipe-7 and
recipe-15 were selected for field efficacy against H. armigera in pigeonpea crop.
Recipe-15 was found significantly more effective than the Dipel® 8L under field
conditions. Physico-chemical properties of the test carriers were evaluated for the
preparation of WP formulation of B. thuringiensis var. kurstaki (HD-1). The results
revealed that barium sulphate registered highest bulk density, whereas, precipitate of
silica had least bulk density. Dolomite was found to be highly alkaline and fuller’s
earth was highly acidic in reaction, whereas, precipitate of silica was nearly neutral.
Moisture content was highest in dolomite and lowest in precipitate of silica. Sorptivity
was found to be highest for precipitate of silica and lowest for dolomite. Specific
surface area for precipitate of silica was highest and for barium sulphate was lowest.
Among the carrier tested precipitate of silica was found to be the most suitable for
preparation of WP formulation of B. thuringiensis var. kurstaki (HD-1).
 
Date 2017-01-03T09:48:58Z
2017-01-03T09:48:58Z
2008
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/94039
 
Format application/pdf