DIFFERENTIAL PREFERENCE OF MAIZE GENOTYPES TO SESAMIA INFERENS WALKER AND ESTIMATION OF AVOIDABLE YIELD LOSSES WITH ENDOSULFAN
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Date
2009
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ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD
Abstract
Studies were undertaken on “Differential preference of maize genotypes to
Sesamia inferens Walker and estimation of avoidable yield losses with endosulfan” under
field conditions during rabi, 2008-09 and laboratory investigations were taken up to
study the ovipositional preference of pink borer to selected maize genotypes at Maize
Research Center, All India Co-ordinated Maize Improvement Project (AICMIP), ARI,
Rajendranagar during 2008.
The varietal screening studies of ten maize genotypes were carried out under
field conditions with artificial infestation of S. inferens and the classification of the maize
genotypes was done based on the dead hearts and leaf injury rating. Among the ten maize
genotypes, Madhuri (5.03) was classified as highly resistant genotype, while BML 7
(5.33) was placed under resistant category. The genotype, HKI 163 (5.87) was classified
as moderately resistant genotype The remaining five genotypes viz., HQPM 1 (6.50), MP
717 (6.93), BML 6 (7.03), BH 40625 and BH 1576 (7.90) were grouped as highly
susceptible.
The ovipositional preference studies of maize genotypes by S. inferens indicated
that the susceptible check, Basi local was more preferred for egg laying while the
resistant check, CM 500 was less preferred. The resistant genotype, BML 7 recorded
significantly more number of eggs under choice and no choice conditions while Madhuri,
the highly resistant genotype recorded more eggs under no choice condition while under
choice condition, it laid fewer eggs. The distribution pattern of eggs on different leaf
sheaths indicated that the moth preferred to lay more than 55% of eggs on first leaf sheath
and the basal and second leaf sheaths were either less preferred or not preferred for
oviposition.
The effect of crop growth stages and larval densities of S. inferens on grain yield
of maize crop under unprotected conditions indicated that the plants artificially infested
with S. inferens larvae at 2 leaf stage (7 DAE) of crop showed maximum reduction in
grain yield (47.59 q ha-1 at 2 leaf stage as against 53.44, 59.84 and 67.34 q ha-1 at 4, 6
and 8 leaf stage, respectively) irrespective of the larval densities. The crop protected with
endosulfan at 2 leaf stage recorded maximum avoidable yield loss ranging from 18.17%
to 45.39% with different larval densities (0, 5, 10, 15 and 20 larvae per plant) and hence
spraying of endosulfan at early stages of crop growth was highly effective for managing
S. inferens and for obtaining higher yields.
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Keywords
DIFFERENTIAL, PREFERENCE, MAIZE, GENOTYPES, SESAMIA, INFERENS, WALKER, ESTIMATION, AVOIDABLE, YIELD, LOSSES, ENDOSULFAN