Life table studies and biorational approaches for the management of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in sunflower
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Date
2014-08-10
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University of Agricultural Sciences GKVK, Bangalore
Abstract
Studies on the life table of Helicoverpa armigera Hub. and biorational
approaches for its management in sunflower were undertaken during 2011-12
to 2012-13 at Zonal Agricultural Research Station, UAS, Bengaluru. Revealed
that the maximum mean progeny production by female (mx) per day was 89.17
females per female on the 43rd day of pivotal age of the life cycle which declined
to 9.15 females per female (mx) per day on 48th day. Life table of H. armigera on
KBSH-44 from field collected life stages revealed that the per cent mortality was
highest in Period I larvae and Period III larvae as compared to that in the Period
II larvae.
Peak incidence of H. armigera was observed during October on DRSH-1
and in November on DRSF-108, in Kharif 2012. In Kharif 2013, the peak
incidence was observed during November on both DRSH-1 and DRSF-108.
Totally 29 species of predatory spiders were recorded during this investigation
in sunflower ecosystem, which belongs to eight families viz., Araneidae (10
species), Salticidae (7), Thomisidae (3), Oxyopidae (3), Tetragnathidae (2),
Miturgidae (2 ), Clubionidae (1)and Linyphiidae ( 1).
Among bio-rational formulations evaluated against H. armigera, spinosad
was significantly superior against H. armigera, it recorded 100 per cent
mortality at 48 hours after treatment (HAT) and 72 HAT and it was followed by
profenophos. From the pooled mean of Rabi seasons of 2012 and 2013 data it
observed that, spinosad based Bio-rational IPM module comprising of
imidacloprid 70 WS (5 g/kg) and metalaxyl 35 WS (5 g/kg) ST + spinosad 45SC
(0.1 ml/lit) first spray at star bud stage and second spray 15 days later was the
most superior module by recording significantly lower incidence of major pests,
highest seed yield (3602 kg /ha) and benefit cost ratio (7.59).
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