Occurrence of silver scurf on potato tubers in depend on meteorological factors and cultivar.

摘要

The damage of tuber skin caused by Helminthosporium solani results in the decrease of quality of potatoes and increases the losses during storage. The infection occurs on young growing tubers and as well as at harvest time. Field studies were conducted in Poland, from 2000 to 2008, to determine the influence of meteorological factors in the time of tuber formation and early growth and before harvest on tuber infection with the pathogen on light soil. The cultivar differences in silver scurf symptoms on tubers were also established. The samples of potato cultivars of various maturity groups were tested for infection with H. solani and its severity index (in 9 degrees scale). Next, the regression and correlation analysis between the soil temperature and total rain in a mentioned phase of plant development and the incidence of silver scurf was determined. There was a linear decrease of infected tubers and their infection with the increase of soil temperature from about 16.0-25.0 degrees C in the period of formation and early tuber growth. In the investigation, the most important factor influencing tuber infection before harvest was total rain. The potato cultivars with different lengths of vegetation period varied statistically with silver scurf symptoms.