INFLUENCE OF MICRO IRRIGATION ON HEALTH STATUS OF CHOSEN POTATO CULTIVARS GROWN IN VERY LIGHT SOIL

The purpose of the study was to determine the effect of microirrigation of ‘Barycz’, ‘Mors’ and ‘Triada’ potato cultivars on the infestation of tubers by selected pathogens. The experiment was carried out in the years 2001-2003 as a split-plot design with three replications. The factors studied were cultivars and irrigation where: W₀ = non-irrigated (control), W₁ = drip-irrigated, W₂ = micro-sprinkler-irrigated. Potato tubers were analyzed immediately after harvest for common scab, black scurf, potato-tuber dry-rot, and potato-tuber soft-rot. A nine-degree scale was used (0-8), where: 0 = lack of infestation symptoms and 8 = at least 50 % of a tuber surface with symptoms of common scab or black scurf. In the case of other diseases a percentage of tubers with symptoms of infestation were estimated. Symptoms of infestation with common scab and black scurf of potato were observed in all years. Infestations of tubers with pathogens causing other diseases were sporadic. The most susceptible to infection with Streptomyces sp. was ‘Barycz’. ‘Triada’ was infected the least. Tubers of ‘Triada’ were contaminated with sclerotia of Rhizoctonia solani to the highest degree. In drip and micro-sprinkler irrigation development of Streptomyces sp. was the weakest. These ways of irrigation were favorable for R. solani development.