Reaction of Selected Potato Varieties to Clavibacter Sepedonicus Infestation under Changing Weather Conditions

The results of the studies carried out over the last 50 years have not provided a clear answer to questions concerning the interaction between Clavibacter sepedonicus (Cs), potato and the environment. The reason is insufficient knowledge of the biology of the causal agent of ring rot, problems of research methodology and the influence of many environmental and biotic factors on the degree of plant infestation. The research conducted in the years 2013–2016 in the Plant Breeding and Acclimatization Institute – National Research Institute concerned the determination of the influence of weather conditions, involved the influence of temperature and Sielianinov hydrothermal coefficient on the development of Cs bacteria in stems and progeny tubers, as well as the occurrence of disease symptoms on plants and in tubers of eight potato varieties. It was found that genotype had the greatest impact on leaf and tuber infestation, while weather conditions were less significant. The results of correlation analysis indicate that the weight of tubers of plants infected by Cs increased statistically significantly with increases in air and soil temperature. On the other hand, air and soil temperature in the initial vegetation period did not significantly affect the number of potato plant tubers infested by Cs. In a 4-year experiment, it was not shown how air and soil temperature and the Sielianinov hydrothermal coefficient affected the degree of potato leaf and tuber infestation. In most cases, potato infestation by Cs caused a decrease in yield.