Record Details

ESTIMATION OF LOSSES AND EVALUATION OF SEED PROTECTANTS AGAINST Sitophilus zeamais Motschulsky IN MAIZE

KrishiKosh

View Archive Info
 
 
Field Value
 
Title ESTIMATION OF LOSSES AND EVALUATION OF SEED PROTECTANTS AGAINST Sitophilus zeamais Motschulsky IN MAIZE
 
Creator VEDA PARIMALA, K
 
Contributor UMA MAHESWARI, T
 
Subject sowing, maize, biological phenomena, insecticides, pesticides, toxicity, storage structures, germinability, grain, antibiotics
Sitophilus zeamais, Motschulsky
 
Description Experiments were conducted on “Estimation of losses and evaluation of seed
protectants against Sitophilus zeamais Motschulsky in maize” during 2010-11 in the
Department of Entomology and Department of Seed Technology, College of Agriculture,
Rajendranagar, Hyderabad. The losses caused by S. zeamais in maize seed was assessed
based on adult emergence, weight loss (per cent), damaged seeds (per cent), germination
and seedling vigour. Relative toxicity of various seed protectants was also studied.
Mean adult emergence ranged from 49.50 to 307.75 over a storage period of six
months where high adult emergence was recorded in the sixth month (307.75) and few in
the first month (49.50). Weight loss and damaged seed due to S. zeamais in maize varied
significantly over a period of six months where weight loss ranged from 0.71 to 9.24 per
cent while damaged seed ranged from 13.94 to 48.24 per cent. The maize weevil affected
germination and vigour index where it was reduced to a maximum of 41.94% and 61.00%
respectively.
Studies made on the effect of certain seed protectants against S. zeamais revealed that
among all the treatments, malathion was found to be superior in causing maximum
mortality of adults (91.79%) seven days after treatment. This was followed by abamectin
causing mortality of 52.50%. Spinosad has recorded a mortality of 42.14% while
deltamethrin recorded 41.79%. Emamectin benzoate was recorded as the least effective
with only 28.21% mortality. When adult emergence of S. zeamais was observed one month
after treatment of maize seeds with seed protectants no adult emergence was observed
from any of the treated seeds.
Treatment of seeds with insecticides had no impact either on seed germination,
seedling vigour index or moisture content of the seed. Germination in the case of treated
seeds ranged from 89 to 93 per cent, highest being recorded in spinosad treated seed
(93.00%) followed by deltamethrin (91.00%) while, vigour index ranged from 2162 to
2089, where deltamethrin recorded maximum vigour index of 2162. The seed moisture of
treated seeds did not vary significantly over the untreated control, where the seed moisture
content ranged from 12.71 to 13.24 per cent during period of storage.
Relative toxicity studies conducted on the insecticides showed that deltamethrin was
most toxic to S. zeamais with LC50 value of 6.85 followed by abamectin (7.26) and
malathion (7.30). Emamectin benzoate has 404.60 followed by spinosad with 100.12 as
LC50 values that were found less toxic. The order of relative toxicity of the insecticides
based on LC50 values after 24 hours period of exposure in the descending order was
deltamethrin (1.06) > abamectin (1.005) > malathion (1.00) > spinosad (0.07) > emamectin
benzoate (0.01). The adult mortality increased marginally at 48 hrs after exposure.
Deltamethrin remained as the most toxic insecticide (LC50 =5.35 ppm) even after 48 hours
of exposure. The LC50 values were 225.75, 55.46, 5.85 and 6.33 ppm for emamectin
benzoate, spinosad, abamectin and malathion, respectively where the order of decreasing
relative toxicity values was deltamethrin (1.18) > abamectin (1.08) > malathion (1.00) >
spinosad (0.11) > emamectin benzoate (0.02).
 
Date 2016-06-09T13:49:02Z
2016-06-09T13:49:02Z
2011
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/67111
 
Language en
 
Relation D8878;
 
Format application/pdf
 
Publisher ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY