Optimizing management interventions against Sclerotium rolfsii Sacc. On elephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson) in India

Abstract

Collar rot, caused by the fungus Sclerotium rolfsii, is the most widespread and devastating disease affecting elephant foot yam (EFY), leading to significant yield loss. In addition to causing economic damage, high disease incidence results in postharvest rot and a lack of quality planting material for the next season. The increasing incidence of collar rot in the past decade is alarming, and existing management practices have not effectively controlled the pathogen. Therefore, there was an urgent need to develop an effective management strategy to mitigate crop loss. The combination of fungicide, Carbendazim + Mancozeb, bio-agents Trichoderma asperellum and Bacillus amyloliquefaciens, showed high inhibition in lab studies. A preliminary field trial was conducted with these selected bio-agents and fungicide, in addition to the organic amendment vermicompost. Based on the results of the preliminary field trial and another study on managing postharvest rot in elephant foot yam, treatments were finalized, and field trials were conducted over 3 years at ICAR-CTCRI. These results were further validated by testing the same treatments in five states of India. Dipping the corms in a combination fungicide (Carbendazim 12% + Mancozeb 63% WP) for 10 min before storage, treating the corms with cow dung slurry enriched with T. asperellum at 5 g/kg corm three days before planting, and drenching the plant base twice with the same fungicide resulted in the lowest disease incidence (3.19%) and highest yield (36.70 t ha⁻¹) compared to 12.85% disease incidence and 28.37 t ha⁻¹ yield in the control.