POPULATION DYNAMICS AND MANAGEMENT OF PINK BOLLWORM, Pectinophora gossypiella (Saunders) IN Bt COTTON
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Date
2023-12-29
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Abstract
The influence of weather factors on pink bollworm indicated that maximum and
minimum temperature, rainfall, morning and afternoon relative humidity having highly
significant, negative correlation with trap catches and larval incidence of pink bollworm.
Among them minimum temperature highly influence on trap catches and larval incidence
with the R2 value of 78.70 and 92.00. The survey conducted on alternate host of pink
bollworm in major cotton growing districts of North-Eastern region of Karnataka recorded nil
incidence of pink bollworm on the different malvaceous host plants.
The pink bollworm completed its life cycle on Bt-cotton and other malvaceous plants
and recorded with the mean total larval period of 21.02 ± 2.40, 18.59 ± 2.03, 18.11 ± 1.93
and 17.75 ± 1.87 days and mean period of life cycle was 42.28 ± 4.22, 37.93 ± 3.84, 37.47 ±
3.74 and 36.91 ± 3.63 days when reared on Bt-cotton, Aelmoschous ficulneus, Abutilon
indicum and Abutilon hirtum, respectively. The larval period was more on Bt cotton (21.02
days) as compared to malvaceous plants (17.75-18.59 days). Similarly, total life cycle was
more on Bt cotton (42.28 days) as compared to malvaceous plants (36.19-37.93 days).The
frequency and time intervention of different insecticides recorded that the lowest larval
incidence (2.25 larvae/10 bolls), green boll damage (20.00 %), bad boll opening (20.25 %),
locule damage (20.21 %) and highest good boll opening (79.75 %) in the treatment, T1 with
four sprays viz., profenofos 50 EC, chlorantraniliprole 18.50 SC, emamectin benzoate 5 SG
and bifenthrin 10 EC at 65, 80, 95 and 110 DAS, respectively with the highest benefit cost
ratio of 1.55.