Bio-ecological Management of Major Insect Pests of Cabbage
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Date
2018
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MPUAT, Udaipur
Abstract
Bio-ecological management of major insect pests of cabbage
Jhumar Lal1* Prof. R. Swaminathan The effect of farmscaping cabbage with marigold, onion, mustard, coriander as
intercrops and cabbage bordered with mustard as trap crop, on the incidence of major
insect pests of cabbage vis-a-vis occurrence of associated natural enemies; and a study
on the efficacy of bio-rational pesticides on the major insect pests were carried out for
two consecutive years in rabi 2015-16 and 2016-17. The major insect pests recorded
were 2 species of aphids, painted bug, flea beetle and diamond back moth during both
years; whereas, tobacco caterpillar and the beet armyworm were recorded as pests
during the crop season in 2016-17. The associated natural enemies comprised 3
species of coccinellids, 2 species of syrphid flies and one species each of the cabbage
aphid parasitoid, DBM pupal parasitoid and the predatory pentatomid bug.
The lowest seasonal mean populations of aphids, flea beetles, painted bug and
DBM were recorded on cabbage bordered with mustard, while the maximum
population on sole cabbage. The tobacco caterpillar attained pest status only during
the crop season 2016-17 and the lowest seasonal mean population was recorded on
cabbage + onion, while the maximum population was recorded on sole cabbage. The
mean atmospheric temperature had a significant positive correlation with flea beetles
in all the farmscaping treatments and sole cabbage during 2015-16. The mean
atmospheric temperature and sunshine hours had a significant positive correlation
with painted bug in the farmscape treatments during 2015-16. The mean atmospheric
temperature had a significant positive correlation with DBM in the farmscaping
treatments; while the mean relative humidity showed a significant negative correlation
with DBM in the treatment cabbage + onion; whereas, DBM population had a
significant positive correlation with mean atmospheric temperature in sole cabbage.
The maximum aphid mummification due to parasitoids, maximum seasonal mean
* Ph. D. Scholar, Department of Entomology, Rajasthan College of Agriculture, MPUAT, Udaipur.
** Professor of Entomology and Dean, Rajasthan College of Agriculture, MPUAT, Udaipur
coccinellids and syrphid larvae were recorded in cabbage + coriander; whereas, the
minimum aphid parasitization, minimum coccinellids and syrphid larvae were
recorded in cabbage sole. The mean atmospheric temperature and sunshine had a
significant positive correlation with the coccinellids. During the crop season 2016-17,
the mean atmospheric temperature and sunshine had a significant negative correlation
with the mean syrphid larval population feeding on aphids. Host-parasitoid
relationship between cabbage aphids and their parasitoids showed a significant
positive correlation between the two in all the farmscape treatments; however, the
maximum parasitoids were collected from the mummified aphids on cabbage +
coriander farmscape treatment. The predator-prey relationships between the prey
aphids and their predatory coccinellids as well as the syrphid fly larvae had a
significant positive correlation.
Farmscaping significantly influenced the natural enemy abundance during
both the years. Aphid parasitization by the parasitoids, coccinellid and syrphid larval
abundance was the maximum in the intercrop cabbage + coriander; whereas, the
minimum coccinellid and syrphid larval abundance was in the intercrop cabbage +
onion. The estimated Shannon-Weiner Indices were relatively the maximum for
cabbage + coriander intercrop. The seasonal mean population of the common natural
enemies of insect pests of cabbage was relatively the maximum in the intercrop
cabbage + coriander and, especially predators like spiders, in the intercrop cabbage +
mustard.
The maximum reduction in aphid population was recorded for neem oil (1%)
followed by spinosad. Neem oil (1%) followed by spinosad had maximum reduction
of flea beetle population 1-day after spray; while, 3 and 7 days after spray spinosad
followed by spinosad gave significantly higher reduction. In the case of painted bug,
the maximum reduction in the population was recorded due to neem oil (1%) followed
by Sl-NPV. The treatment schedule spinosad followed by spinosad was most effective
in having significantly lowest DBM population 1, 3 and 7 days after spray during both
the years. The response was at par with indoxacarb followed by indoxacarb. Three
days after spray, significantly minimum population of tobacco caterpillar was
recorded in the treatment neem oil (1%) followed by spinosad and indoxacarb
followed by indoxacarb; whereas, 7 days after spray the minimum population was
recorded in the treatment schedule neem oil (1%) followed by Sl-NPV. The biorational
pesticides evinced no significant side effects on the natural enemy population.
Farmscaped cabbage had a significant influence on yield with the maximum in
cabbage + coriander.. The maximum cabbage yield, net profit and highest cost benefit
ratio were recorded for treatment of Neem oil followed by spinosad
Description
Bio-ecological management of major insect pests of cabbage
Keywords
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Citation
Lal. J , and Swaminathan. R