Efficacy of Eco-compatible Inputs for Managing Black Scurf Disease of Potato (Solanum tuberosum L.) incited by Rhizoctonia solani Kuhn

Black scurf disease caused by Rhizoctonia solani significantly impacts potato (Solanum tuberosum L.) production, causing substantial yield losses. This study evaluated integrated management strategies combining biological and chemical components for black scurf control under field conditions. In vitro screening demonstrated that 3% boric acid achieved 89.87% inhibition of fungal growth, while Trichoderma harzianum showed 85.24% growth inhibition in dual culture assays. Field trials were conducted during Rabi 2024–25 using a randomized complete block design with seven treatments and three replications. The most effective treatment comprised soil application of spent mushroom substrate + seed treatment with T. harzianum + foliar application of 2% boric acid, which significantly improved germination (89.70%), plant height (61.3 cm at 63 DAS), and yield (10.9 kg plot⁻¹) compared to untreated controls (5.7 kg plot⁻¹), representing a 91.22% yield increase. This treatment reduced disease incidence to 15% and severity to below 12%, achieving 81.54% disease control efficacy with a Black Scurf Disease Index of 3.53 compared to 21.49 in controls. These findings establish integrated management strategies as effective sustainable alternatives to conventional chemical control methods for black scurf disease management in potato cultivation.