Biology, Epidemiology and Management of Rhizoctonia solani on Potato

Black scurf and stem canker on potato is an economically important disease complex, causing both quantitative and qualitative damage to potato crops which occurs in potato production areas throughout the world. The ribosomal DNA internal transcribed spacer sequence analysis is currently accepted and a commonly used method for classifying Rhizoctonia species and anastomosis groups (AGs). To date, 13 AGs have been recognized. The updated AG distribution in potato worldwide production areas confirm the status of AG-3 as the most prevalent AG in potato and reflects the population dynamics of the pathogen probably due to global trading of tubers. As R. solani is a tuber-and soilborne pathogen, the ability to detect its levels in the seed tubers and in the soil and predict the potential damage is an important factor in controlling the disease. Effective disease management of Rhizoctonia disease requires implementation of an integrated disease management approach and knowledge of each of its stages. Although the most important control measures are cultural, chemical control (either by seed tuber-or in-furrow treatments) is still an important tool in reducing the damages caused by R. solani.