ABSTRACT

Pigeonpea (Cajanus cajan) is a vital pulse crop, with India being the largest producer. However, its productivity is significantly threatened by Fusarium udum, a major fungal pathogen that causes substantial economic losses. A roving survey conducted during the Kharif 2023-24 season in the Vijayapur and Kalaburagi districts recorded a wilt incidence of 29.98 per cent in Vijayapur and 23.64 per cent in Kalaburagi.
In this study F. udum cultural characteristic was evaluated on seven different media. PDA showing the highest mycelium growth (89.00 mm), while sporulation was highest on V8 Juice, Oat Meal, PDA and Malt Extract Agar. F. udum isolates on PDA exhibited growth ranging from 68.36 mm to 88.66 mm. Ganagapur and Mandeval isolates had the highest sporulation and macroconidia contained 2-6 septa. DNA and phylogenetic analyses were done for all 10 F. udum isolates and these were divided into two main genetic clusters which indicating notable genetic diversity among the isolates.
In the management study, carbendazim 50% WP, propiconazole 25% EC and tebuconazole 25.9% EC were the most effective systemic fungicides, achieving 100 per cent inhibition against F. udum at all tested concentrations. Among combi fungicides, carbendazim 12% + mancozeb 63% WP, hexaconazole 4% + zineb 68% WP, captan 70% + hexaconazole 5% WP and prochloraz 24.4% + tebuconazole 12.1% EW achieved 100 per cent inhibition at all concentrations. Among the tested bio-agents Trichoderma harzianum was the most effective 56.48%) against F. udum. Seed treatment with chemical fungicides proved more effective than bio-agents in managing Fusarium wilt under field conditions. Captan 70% + hexaconazole 5% was the most effective, resulting in the lowest disease incidence (3.10%) and highest yield (15.49 q/ha).