Population dynamics and management of helicoverpa armigera (Hubner) in tomato
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Date
2018
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CCSHAU
Abstract
Field studies on the population dynamics and management of H. armigera on tomato were carried out
at Research Farm, Department of Entomology, CCS Haryana Agricultural University, Hisar during Rabi, 2016-
17. Results showed that eggs of H. armigera were present in field during 9th to 21st SMW whereas larval
population was available from 10th to 22nd SMW. Maximum number of eggs and larval population was recorded
during 15th SMW (4.92 eggs/ plant) and 16th SMW (5.1 larvae/ plant), respectively. Fruit infestation both on
number and weight basis were recorded to be maximum during 3rd picking (20th SMW). Aphid and whitefly
population attained a peak during 12th (25.2 aphids/ plant) and 16th SMW (5.78 whiteflies/ three leaves),
respectively. Larval population of H. armigera exhibited a significant positive correlation with maximum (r=
0.669) and minimum temperature (r= 0.452) whereas highly significant negative correlation with evening and
morning relative humidity with r= -0.785, -0.850, respectively. Multiple linear regression analysis showed that
evening relative humidity contributed to fluctuation of H. armigera eggs to the extent of 31 per cent.
Similarly, maximum temperature, minimum temperature, morning and evening relative humidity accounted
for 80 per cent variability in larval population of H. armigera.Maximum parasitization (13.8%) of H.
armigera eggs, coccinellids (0.76/ plant) and syrphid fly maggot population (4.2 larvae/ plant) were recorded
during 13th SMW whereas spiders attained a peak (0.92/ plant) during 12th SMW. Correlation studies revealed
that egg parasitization of H. armigera showed significant positive correlation (r= 0.988) with number of H.
armigera eggs present in the field and coccinellids were positively correlated with number of eggs of H.
armigera, aphids and whitefly present with r value of 0.777, 0.533 and 0.689, respectively. Population of
spiders showed a significant positive correlation with number of H. armigera eggs and whitefly. Syrphid fly
maggots were significantly and positively correlated with aphid population (r= 0.796). Evaluation of different
management modules against H. armigera revealed that minimum eggs counts (0.60 eggs/ plant) and larval
population (0.43 larvae/ plant) of H. armigera was recorded in module 4 (intercropping of tomato with
marigold in 2:1 with a border row of marigold, release of Trichogramma chilonis @ 50,000/ ha, application of
nimbecidine 1500 ppm @ 2.5 L/ ha followed by each other) and module 5 (spray of chlorantraniliprole 18.5 SC
@ 150 ml /ha and spray of indoxacarb 14.5 SC @ 450 ml /ha), respectively. Module 4 (intercropping of tomato
with marigold in 2:1 with a border row of marigold, release of T. chilonis @ 50,000/ ha, application of
nimbecidine 1500 ppm @ 2.5 L/ ha followed by each other) was recorded to be most economical from farmers
perspective with highest B:C ratio (3.98).
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