SURVEY ON INSECT PESTS, BIOEFFICACY AND DISSIPATION STUDIES OF CERTAIN INSECTICIDE MOLECULES ON CAPSICUM
Loading...
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY. HYDERABAD
Abstract
The survey on the occurrence of major insect pests of capsicum was conducted in
open field and poly house conditions in and around Hyderabad, Telangana and also in
Guntur district of Andhra Pradesh during 2013-14. Field and poly house experiments were
carried out during 2013-14 and 2014-15 at Horticulture Garden, Department of
Horticulture, College of Agriculture, Professor Jayashankar Telangana State Agricultural
University (PJTSAU), Rajendranagar, Hyderabad, wherein the bio-efficacy of seven
insecticides along with untreated check were evaluated against pest complex of capsicum.
Studies were undertaken to establish dissipation dynamics of selective
insecticides, viz., spinosad, flubendiamide, chlorantraniliprole, spiromesifen, thiamethoxam
and triazophos at recommended dose both in open field and poly house situations to assess
the differences in rate of dissipation and also to recommend Pre-Harvest Intervals based on
MRLs established by Codex Alimentarius Commission (CAC) and Food Safety and
Standards Authority of India (FSSAI).
The fixed plot survey conducted in and around Hyderabad, Telangana revealed that,
under open field conditions, the mean population of thrips, Scirtothrips dorsalis Hood
(no./leaf) ranged from 9.60+0.47 to 12.24+1.20 and for mites, Polyphagotarsonemus latus
Banks 5.94 +0.79 to 10.64+2.34, respectively. The per cent damage per plant caused by cut
worm, Agrotis ipsilon (Hufn.), blossom midge, Asphondylia capsici Barnes and fruit borer,
Spodoptera litura Fab ranged from 2.12+ 0.78 to 5.33 + 0.56, 2.75+0.49 to 9.26+3.19 and
5.26+0.91 to 17.8+3.89, respectively. The per cent yield loss caused by these pests ranged
from 54.90 + 1.22, 36.00+ 0.68, 27.00 + 0.97, 41.60+ 1.09 and 58.10+ 1.29 per cent,
respectively. In poly house the mean population of thrips, mites, aphids and whiteflies
ranged from 1.87 +0.66 to 4.99 + 1.75, 1.10 + 0.65 to 4.56 +1.42, 0.68 +0.77 to 2.94 +2.06
and 0.05 +0.3 to 1.13 +0.45, respectively. The per cent damage per plant caused by cut
worm ranged from 1.01+ 0.70 to 4.04 + 0.98, blossom midge, 0.66 +0.59 to 4.05 +1.53
and fruit borer, 1.03 + 0.59 to 5.42 +0.8181, respectively during crop season. The per cent
yield loss varied and it was found to be 36.81 + 1.94 for thrips, 27.06 + 1.21 for mites,
5.31+0.58 for aphids, 4.50+0.55 for whiteflies, 25.75+1.02 for cutworm, 35.44+1.25 for
blossom midge and 39.00 +1.09 for pod borer.
The roving survey conducted in Guntur district of Andhra Pradesh revealed that at
seedling stage, the mean population (no. of / leaf) of thrips, aphids and whiteflies ranged
from 1.25+0.47 to 2.71 + 0.59, 0.56 +0.49 to 1.89+0.77 and 1.24+0.19 to 2.36+0.23,
respectively. Mean per cent damage caused by cut worm ranged from 1.35 + 0.22 to and
2.91 + 0.53. At vegetative stage, mean population (no. of / leaf) of thrips ranged from 2.06
+ 0.07 to 5.29 + 0.41, whereas, for other pests viz., mite, 0.70 +0.33 to 3.71 + 0.75,
aphids, 0 .59 + 0.45 to 2.23 +0.26, whiteflies, 1.23+0.33 to 2.78 + 0.50, respectively. At
reproductive stage, mean population (no. of / leaf) of thrips, ranged from 0.19 + 0.15 to
0.76 + 0.15, whereas for aphids, 0.66 + 0.04 to 0.36 + 0.70, blossom midge, 1.14 + 0.54 to
2.32 + 0.34 and fruit borer, 2.58 + 0.44 to 9.21 +2.05 were reported. Under shade net
conditions, thrips, caused 47.38 + 2.26, mite 25.46 + 1.53, aphids, 9.33+ 0.79, whiteflies,
12.2 + 0.91, cut worm, 33.88+1.37, blossom midge, 43.11 + 2.01 and fruit borer, 52.05+
2.59 per cent yield loss, respectively.
Results from bio-efficacy of insecticides against pest complex of capsicum, under
open field and poly conditions in the 2013-14 and 2014-15indicated, spinosad as the best
and effective treatment in reducing the thrips population by recording highest per cent
reduction over control, followed by diafenthiuron and thiamethoxam, respectively. Against
mite, spiromesifen was the most effective one with a maximum reduction of population
followed by diafenthiuron, respectively. In 2013-14 and 2014-15 under poly house
conditions, the highest per cent reduction of aphid population was recorded with
thiamethoxam. Against blossom midge studies under open field conditions indicated that,
the lowest per cent damage and highest per cent reduction was recorded with
flubendiamide (100.00) in both years (2013-14 and 2014-15) of the study.
Diafenthiuron exhibited highest yield (32,500 kg ha-1) and was followed by
spinosad (29,970) and spiromesifen (27,760) under open field conditions during 2013-14
where as under poly house conditions, spinosad (39,110 kg ha-1) recorded highest yield
followed by diafenthiuron (39,050 kg ha-1). During 2014-15, spinosad (34,260 kg ha-1)
recorded highest yield followed by diafenthiuron (33,930 kg ha-1) under open field and
poly house conditions.
The dissipation pattern of insecticides varied in open field and poly house, where
initial deposits were comparatively higher and dissipated slowly in poly houses. In open
field situation, initial deposits of chlorantranilipole, triazophos, spinosad, flubendiamide,
spiromesifen and thiamethoxam were 0.36, 2.13, 0.61, 1.50, 1.29 and 1.62 mg kg-1,
respectively and dissipated to below determination level by 7.00, 10.00, 7.00, 10.00, 7.00
and 7.00 day respectively. In poly house conditions, initial deposits of above insecticides
were1.31, 3.19, 1.60, 2.40,1.61 and 2.77 mg kg-1, respectively and dissipated to below
determination levels by 10.00, 20.00, 20.00, 15.00, 10.00 and 15.00 days, respectively