Summary:

The aim of the study was to determine the impact of microirrigation of Barycz, Mors and Triada potato cultivars on the infection of tubers by the most dangerous pathogens. The experiment was carried out on light soil as a two-factor split-plot design with four replications. The factors were cultivars and the following variants of irrigation: WO - without irrigation, W1 - drip irrigation, W2 - micro-sprinkler irrigation. The health status of tubers was evaluated after harvest in each year of the study. The percentage of an area of the tubers with symptoms of common scab and black scurf was determined following nine-degree (0-8) scale were: 0 = lack of disease symptoms, healthy tubers and 8 = above 50% of a tuber surface with disease symptoms. The percentage of tubers with symptoms of in-festation was estimated for other detected diseases. Symptoms of common scab and black scurf were observed on the tubers in all years of the study. Studied cultivars differed in susceptibility to Streptomyces sp. and Rhizoctonia solani. The most resistant cultivar to the first pathogen was Triada and to the second pathogen was Barycz. Symptoms of other diseases were noted sporadically and did not exceed 1% of infected tubers. There was no significant effect of the microirrigation on the occurrence of common scab and black scurf of the tubers.