Assessment of Severity of Soybean Anthracnose in North Eastern Karnataka, India
M. B. Meghana *
Department of Plant Pathology, College of Agriculture, University of Agricultural Sciences, Raichur - 584 104, Karnataka, India.
S. B. Gowdar
Department of Plant Pathology, College of Agriculture, Gangavathi - 583 227, University of Agricultural Sciences, Raichur - 584 104, Karnataka, India.
Y. S. Amaresh
Department of Plant Pathology, College of Agriculture, University of Agricultural Sciences, Raichur - 584 104, Karnataka, India.
D. S. Aswathanarayana
Department of Plant Pathology, College of Agriculture, University of Agricultural Sciences, Raichur - 584 104, Karnataka, India.
Umesh Hiremath
Seed Unit, UAS, Raichur - 584 104, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
Soybean (Glycine max (Merrill)) is a globally important oilseed and leguminous crop valued for its protein, oil and industrial applications, with India ranking fourth in area and sixth in production worldwide. Anthracnose, caused by Colletotrichum truncatum (Schwein) Andrus and Moore, is one of the most destructive seed-borne fungal diseases of soybean, capable of causing yield losses of up to 100 per cent under favourable conditions. A roving survey was conducted during Kharif 2025 across major soybean-growing districts of North Eastern Karnataka, viz., Bidar, Kalaburagi, Raichur and Yadgir to assess the incidence and severity of anthracnose. Disease severity was recorded on a 0 - 9 scale and expressed as Per cent Disease Index (PDI). The PDI ranged from 24.44 to 82.22 per cent across surveyed locations, with Bidar district recording the maximum mean disease severity (69.00 %), followed by Kalaburagi (61.36 %) and Yadgir (34.56 %), while Raichur recorded the minimum (24.44 %). Among the varieties observed, KDS - 126 showed the highest mean PDI (67.59 %), followed by JS - 335 (63.55 %) and DSB - 34 (51.11 %). Variation in disease severity across locations was attributed to differences in rainfall, relative humidity, leaf wetness duration, varietal susceptibility and local cultivation practices. The findings underline the widespread prevalence and high severity of anthracnose in the region and highlight the need for integrated disease management strategies.
Keywords: Soybean, anthracnose, Colletotrichum truncatum, per cent disease index, roving survey, disease severity