Effect of soil water tension and harvest time on levels of infestation byPhoma foveata Foister in soil and on tubers and stems of potato (Solanum tuberosum L.) in northern Sweden

The incidence ofP. foveata in soil and tuber samples from field experiments often increased significantly as the harvest season progressed and temperatures fell. Mean levels of tuber and soil infestation were significantly higher in irrigated rows compared with those artificially sheltered from precipitation, both at normal and late harvest dates.