Asian Journal of Soil Science and Plant Nutrition

Black scurf of potato caused by Rhizoctonia solani Kühn is a major soil-borne disease responsible for significant yield and quality losses in potato-growing regions. Field experiments were conducted during 2024–25 and 2025–26 at SIF, C.S.A.U. & T., Kanpur, to evaluate the efficacy of different fungicides and biofungicides against black scurf disease under field conditions. A total 17 treatments comprising tuber treatment and soil drenching with biofungicides (Trichoderma harzianum, T. viride, Pseudomonas fluorescens, Bacillus subtilis) and fungicides (penflufen, pencycuron, carbendazim + mancozeb, and thiram) were tested in a randomized block design with three replications using infected seed tubers of cv. Kufri Chipsona-1. The results from both years revealed that all treatments significantly improved germination, plant growth, and yield while reducing disease incidence, severity, and black scurf disease index (BSDI) compared to untreated control. Among all treatments, tuber treatment with pencycuron 22.9 SC @ 0.25% proved most effective, recording the highest germination (up to 93.66%), maximum plant height (up to 59.74 cm), lowest disease incidence (7.83%), severity (3.46%), and BSDI (0.36%), along with the highest tuber yield (326.73 q/ha). This was closely followed by penflufen 240 FS @ 0.083% and Trichoderma harzianum treatments. Whereas, biofungicides were moderately effective, with T. harzianum performing better than other bioagents. In contrast, the untreated control recorded the highest disease incidence (up to 41.63%) and lowest yield (248.33 q/ha). Overall, the study demonstrates that tuber treatment with pencycuron, followed by penflufen and T. harzianum, is highly effective for managing black scurf disease of potato under field conditions. Integration of chemical fungicides with biofungicides can be a promising strategy for sustainable disease management.