Variability and Integrated Management of Spot Blotch of Wheat Caused by Bipolaris sorokiniana (Sacc.) Shoem.
Loading...
Files
Date
2017-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Agricultural Sciences, Dharwad
Abstract
Laboratory and field experiment were conducted at Department of Plant
Pathology, College of Agriculture and Main Agricultural Research Station, Dharwad to
study the variability and integrated management of spot blotch of wheat.
Roving survey conducted in Dharwad, Belagavi, Gadag, Bagalkote and
Vijayapura districts during rabi, 2017-18 indicated low severity of spot blotch disease.
Variability study in 14 isolates of B. sorokiniana through morphological and cultural
characters, pathogenic ability and SSR markers had showed high distinction. Colony
colour ranged from whitish black to black. On the basis of pathogenicity, 14 isolates
were grouped into two different pathotypes (P1 and P2). Similarity coefficients were
ranged from 0.53 to 0.98 representing less than 53 per cent genetic variability among
isolates.
Under in vitro studies, captan at 0.3 % (86.29 %), hexaconazole, propiconazole
and tebuconazole at 0.025 %, 0.05 %, 0.1 % (100%), hexaconazole 5 % + captan 70 %
WP, carboxin 37.5 % + thiram 37.5 % WP and tebuconazole 50 % + trifloxistrobin
25 % WG at 0.05 %, 0.1 %, 0.2 % (100%), multineemore at 1.0 % (54.81 %)
recorded maximum inhibition of mycelial growth. Trichoderma harzianum +
Pseudomonas fluorescens + Bacillus subtilis (3.3 g each/l) concentration, panchagavya
(20 %) inhibited 80.44 and 30.29 per cent spore germination, respectively.
In Integrated disease management, among the eight spray schedules evaluated
under field condition, two sprays of hexaconazole 5 % EC (0.1 %) with 15 days interval
reduced the spot blotch severity by 13.40 per cent with highe st grain yield (13.33 q/ha),
biomass (8.33 t/ha) and BC ratio (1:1.94). Hexaconazole 5 % EC (0.1 %) was most
effective in managing spot blotch disease.