Occurrence of common scab and black scurf in selected potato cultivars grown under organic and conventional crop production systems

The research was carried out in 2014–2017 at the Institute of Plant Breeding and Acclimatization, in the Jadwisin Branch, in the center of Poland. The subject of the research were potato tubers grown in an organic and conventional system, assessed for symptoms of common scab and black scurf. Seven cultivars belonging to two groups of earliness were examined. It was found that the share of tubers with common scab symptoms depended on the cultivar, the conditions prevailing in the research years and the production system. A higher share of infected tubers was found on tubers from the organic system, although statistically significant differences were observed in one year of research. The degree of tuber infestation depended on the variety and production system. Significant differentiation in terms of the share of tubers infected with Rhizoctonia solani and the degree of tuber infestation was observed between the cultivars and the production system. The cultivars Bogatka and Oberon were the least susceptible to infection with R. solani and bacteria of the genus Streptomyces in the organic system.