SEASONAL INCIDENCE OF TOBACCO CATERPILLAR AND AMERICAN BOLLWORM IN GROUNDNUT AND BIO-EFFICACY OF NOVEL INSECTICIDES AGAINST BOLLWORM COMPLEX
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Date
2022-08-25
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Banda University of Agriculture &Technology, Banda-210001, Uttar Pradesh (India)
Abstract
The present investigations were carried out at Research Block of College of Agriculture,
BUAT, Banda during Kharif 2021 for study the incidence of two important defoliators viz.,
Tobacco caterpillar, S. litura and American bollworm, H. armigera on groundnut variety
Dharani.
The result revealed the tobacco caterpillar first noticed on early stage of the crop followed
by American bollworm and continued till harvest. The incidence of both the insect-pests was
fluctuating under varying weather conditions. Of these, S. litura initiated with mean larval
population of 0.21 plant-1
and reached it maximum (7.01 larvae plant-1
) in last week of
September (39thSW), Whereas H. armigera initiated with mean larval population of 0.19
plant-1
in 4thweek of August (34thSW) and reached to its maximum (5.02 larvae plant-1
) in first
week of October (40thSW).
The meteorological variable had non-significant correlation except maximum relative
humidity. The temperature (max. & min.) and minimum RH had positive correlation whereas
the rainfall had negative correlation with larval population of S. litura. However, the H.
armigera had positive correlation with max. temp. and max. RH, whereas it had negative
correlation with min. temp., min RH and rainfall.
Two predator species viz., coccinellids and spiders were recorded at different stages of the
crop growth. The coccinellids were first noticed in 3rdweek of August (33rdSW) however,
appearance of spiders was first noticed in 32ndSW. The results revealed that population of
natural predators was gradually increased with an increase of the larval population bollworm
species and significantly correlated.
Among tested insecticides, chlorantraniliprole 18.5 SC @ 30g a.i. ha-1
followed by
cyantraniliprole 10 OD @ 90g a.i. ha-1
and novaluron 5.25 + indoxacarb 4.5 SC @
39.38+33.77g a.i. ha-1were found most effective against S. litura and H. armigera, that
significantly reduced the larval population with maximum per cent field bioefficacy in
groundnut. The maximum yield (22.37 qha-1
), increase over control (52.00 per cent), net return
(Rs.55765.00 ha-1
) were recorded from chlorantraniliprole 18.5 SC followed by
cyantraniliprole 10 OD and novaluron 5.25 + indoxacarb 4.5 SC. Based on cost: benefit ratio,
chlorantraniliprole 18.5 SC (1:6.80) was most economical followed by flubendiamide 20 WG
(1:5:12) and lambda cyhalothrin 5 EC (1:3.92).
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Citation
Jagmohan. 2022. SEASONAL INCIDENCE OF TOBACCO CATERPILLAR AND AMERICAN BOLLWORM IN GROUNDNUT AND BIO-EFFICACY OF NOVEL INSECTICIDES AGAINST BOLLWORM COMPLEX. Thesis, M.Sc.