VIEW ARTICLE

Ecology and Epidemiology

Comparison of Tuberborne and Soilborne Inoculum in the Rhizoctonia Disease of Potato. J. A. Frank, Research plant pathologist, Agricultural Research, Science and Education Administration, Department of Plant Pathology, The Pennsylvania State University, University Park, 16802; S. S. Leach, research plant pathologist, Agricultural Research, Science and Education Administration, Northeastern Plant, Soil and Water Laboratory, Orono, ME 04473. Phytopathology 70:51-53. Accepted for publication 15 June 1979. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1980. DOI: 10.1094/Phyto-70-51.

Field and greenhouse testing confirmed that both tuberborne and soilborne inocula of Rhizoctonia solani were important in the development of the Rhizoctonia disease of potato. Five criteria were included in the disease rating: percentage of sprout emergence, stem lesions, stolon lesions, pruned stolons, and percent usable tubers. Tuberborne inoculum primarily affected sprout emergence and soilborne inoculum generally contributed to stolon damage. Lack of visible R. solani sclerotia on tubers was not sufficient to indicate absence of the pathogen. Control of tuberborne inoculum is an essential part of an integrated program for control of R. solani on potatoes.