Symptomatology and Management of Alternaria Leaf Blight in Fenugreek (Trigonella foenum-graecum L.)

Abstract

Alternaria leaf blight, caused by Alternaria alternata, is an emerging foliar disease of fenugreek (Trigonella foenum-graecum L.) in major growing regions, including Rajasthan, India. Field surveys recognised characteristic symptoms of the disease, including necrotic spots with concentric rings, apical blighting, and leaf desiccation. Pathogen Alternaria alternata was identified and confirmed through morphological analysis and ITS-based molecular sequencing, and pathogenicity was validated through detached leaf and pot culture assays. Field experiments were conducted to evaluate the effect of sowing dates, bioefficacy of fungicides and plant extracts, and genotype resistance under natural epiphytotic conditions. While sowing date had minimal impact on disease severity, earlier sowing optimized yield. Among fungicides, propiconazole and difenoconazole were the most effective at suppressing disease, while neem oil and garlic extract were the most effective botanicals. Genotypes A3-23-3 and C2-55-4 showed tolerance to Alternaria leaf blight under field conditions.