Bio-Ecology and Management of Major Insect Pests of Chilli (Capsicum annum L.)
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Date
2018
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Publisher
MPUAT, Udaipur
Abstract
The investigations on the “Bio-ecology and management of major insect pests of
chilli (Capsicumannum L.)” were carried out for two consecutive years (kharif, 2015 and
2016) at the instructional farm of Horticulture, Rajasthan College of Agriculture,
Maharana Pratap University of Agriculture and Technology, Udaipur, with the objectives
of studying the seasonal incidence of major insect pests, occurrence of associated natural
enemies; estimation of losses; screening of a few varieties for their susceptibility to the
pests and evaluation of insecticides and bio-pesticides against them. The study revealed
that whitefly incidence commenced in the first week of August during both the years,
peaked in the second week (8.53/plant) of October (2015) and fourth week (10.07/plant)
of September (2016).Thrips infestation began in August (first week during kharif, 2015
and second week during kharif, 2016)reaching the peak in the first week (11.80 &
11.60/plant) of October during both respetive years. Aphid incidence commenced in the
second week of August during both the years and reached the peak in the third week
(13.60 &12.93/plant) of Septemberduring both respetive years. Two species of
coccinellids viz., Ch. sexmaculata and C. septempunctata were recorded as common
natural enemies. Theiroccurrencecommenced in the second week of Augustduring kharif,
2015 and third week of Augustduring kharif, 2016. Ch. sexmaculatapopulation peaked in
the fourth week (4.13 & 4.27/plant) of September during both respective years; whereas,
C. septempunctata was at its peak in the first week (4.53/plant) of October duringkharif,
2015 and third week (4.53/plant) of September during kharif, 2016.Whitefly, thrips and
aphid exhibited a significant negative correlation with rainfall during both years;
whereas,significant positive correlation with mean temperature was noted during kharif,
2016. The correlation between Ch. sexmaculata and C. septempunctata population with
total rainfall exhibited a significant negative correlation during both years; however, C.
septempunctata also exhibited a significant negative correlation with mean relative
humidity duringkharif, 2015; whereas,Ch. sexmaculata and C. septempunctata population
had significant positive correlation with mean temperature during both years. The
correlation between aphids and coccinelids viz.,Ch. sexmaculata(r =0.882, 0.794) and C.
septempunctata(r =0.881, 0.876) was significant and positive during both years depicting
a density-dependent predator-prey activity.
The pest adversely affected the different yield attributing parameters like the
average height of plants, number of primary branches, number of fruits and marketable
fruit yield and the avoidable loss estimated was 51.19 and 38.51 per cent fruit yield.
Mathania local harboured the lowest number of whiteflies (2.78,2.71), thrips
(3.04,2.93) and aphids (2.57,2.48)as observed during the respective years. Variety Pusa
Jwala was the most preferred variety (whiteflies: 4.58,4.48; thrips: 5.17,5.08; and aphids
4.46,4.59 during the respective years) by the sucking insect pest complex. None of the
variety was free from the leaf curling; the minimum leaf curling was recorded in the
variety Mathania Local(30.55, 30.91 %) during the respective years. The maximum leaf
curling was on the variety Pusa Jawala (48.81,49.72) in the respective years.
Among different management treatmentsevaluated, imidacloprid 17.8 SL was
most effective causing maximum cumulative populationreduction of whitefly
(79.00,76.83), thrips (77.93,78.69) and aphids(76.08,78.26) in the respective years 7 days
after the treatments. Among all the treatments NSKE (5%) and NLE(10%) were least
effective against sucking pests during both the years. The highest marketable yield of
green chilli during kharif, 2015 and 2016 was recorded in the treatment of imidacloprid
17.8 SL. Among the insecticides, imidacloprid was relatively safer to the coccinellids.
Description
Bio-ecology and Management of Major Insect Pests of Chilli (Capsicumannum L.)
Keywords
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Citation
Yadav, S.K. and Swaminathan, R.