Evaluation of organic vinegar treatments and black gram [Vigna mungo (L.) Hepper] genotypes for the management of pod rot disease caused by Fusarium humuli

Black gram ( Vigna mungo (L.) Hepper) is an important pulse crop valued for its nutritional benefits, soil-enriching nitrogen fixation, and use as animal feed. However, new diseases threaten its productivity, notably pod rot caused by Fusarium humuli , recently reported from Pantnagar, India. This study evaluated the efficacy of vinegars and pongamia oil under in-vitro and field conditions, and screened genotypes for resistance. In-vitro assays showed that Tebuconazole 25.9% EC achieved 100% mycelial inhibition at all concentrations. Among organic treatments, apple vinegar provided complete inhibition (100%) at 1.0% concentration and above, while sugarcane vinegar also maintained high efficacy across doses. Field trials revealed disease control ranging from 2.25% (Jamun vinegar 2.5% + hot water at 55°C for 10 min) to 52.83% (Seed treatment with Tebuconazole 1 g/kg + foliar spray of Tebuconazole 25.9% EC at 0.2%). Apple vinegar and sugarcane vinegar, used as seed and foliar treatments, recorded 42.70% and 41.56% disease control, respectively, along with enhanced plant growth, indicating their dual role in management and crop health. Screening of 50 genotypes during 2022–2023 identified 32 moderately resistant and 15 moderately susceptible lines, but none showed complete resistance. Apple and sugarcane vinegar thus emerged as the most effective organic options, with apple vinegar showing strong potential as a cost-effective, eco-friendly alternative. Overall, integrated approaches combining moderately resistant genotypes and organic treatments are essential for sustainable pod rot management in black gram.