Effects of soil disinfection and potato harvesting methods on stem infection by Rhizoctonia solani Kuhn in the following year

A two year field experiment was conducted twice to assess effects of chemical soil disinfection at planting and methods of harvesting potatoes on stem infection with Rhizoctonia solani in the subsequent year. In the first year of the experiments seven methods, including one with soil disinfection at planting, were applied in August. In the following year, X. solani stem and stolen infection (disease severity) on potato plants were assessed in June. Soil treatment at planting with pencycuron resulted in lowest disease severity in the following year. Compared with chemical haulm killing and haulm pulling, immature-crop-harvesting also resulted in a lower disease severity, but only when black scurf was scarce on tubers at harvest in the preceding year.