New Horizons in Insect Science Towards Sustainable Pest Management

277

Integrated Management of

Insect-Induced Reddening in Bt

Cotton Hybrids

Vijaykumar N. Ghante, Rajesh Chowdary, M. Bheemanna,

Hosamani Arunkumar and Ranjith Kumar

A. K. Chakravarthy (ed.), New Horizons in Insect Science: Towards Sustainable Pest Management,
DOI 10.1007/978-81-322-2089-3_25, © Springer India 2015

V. N. Ghante () · R. Chowdary · M. Bheemanna ·
H. Arunkumar · R. Kumar
Main Agricultural Research Station, UAS, Raichur,
Karnataka, 584102, India
e-mail: [email protected]

Abstract

Studies on the factors responsible for reddening in Bt cotton are due to in-

creased incidence of sucking pests, especially leafhoppers, use of suscep-

tible hybrids and improper nutrient management. Validation of integrated

module comprised use of sucking pest-tolerant cotton hybrid; balanced

and timely soil application of macro- and micro-fertilizers as per recom-

mendation based on site-specific soil test results; threshold-based man-

agement of sucking pests, especially leafhoppers, using systemic insecti-

cides; foliar applications of Mancozeb 75WP at 2 g/L against leaf spot dis-

ease; three foliar applications of water-soluble multinutrient mixtures at

4 ml/L during 60, 75 and 90 DAS and weeding during first 40 DAS proved

best for the management of Bt cotton reddening. Differential response to

reddening was found among the cultivated commercial Bt cotton hybrids.

Among the hybrids tested, Jackpot, MRC-7347, Marvel and MRC-7351

were found tolerant to sucking pests and, in turn, the manifestation of red-

dening symptoms. Bt hybrids such as RCH 2, RCH 530, Brahma, Arya

and Bunny were highly sensitive to insect-induced reddening.

Introduction

Reddening in Bt cotton is one of the most com-

plex problems in Bt cotton-growing areas of

India. Thousands of acres of cotton were found

to be affected by this problem in major cotton-

growing belts of many states. Worldwide studies

revealed multifaceted factors responsible for red-

dening in cotton (Praharaj and Sankaranarayanan

2010 ). Both biotic and abiotic factors have been

Keywords

Bt cotton · Integrated management · Leafhoppers · Reddening