Heavily diseased tubers have been found in 1994 and 1995 in a vegetable garden in the Matanuska valley near Wasilla. Life cycle slide set available now. You can now order an illustrated life cycle of Spongospora subterranea f.sp. In South Africa seed producers are confronted with powdery scab in a region where mostly hot and sandy soils can be found. That's why irrigation is normal practice.
Research is ongoing.
Spongospora subterranea f. sp. Diseased potatoes have been found in 1994 for the first time and the presence of cystosori and pathogenicity of infected tissue were confirmed. Interestingly environmental conditions in North Dakota including high soil pH, low rainfall and high temperatures are not at all favourable for powdery scab. In Japan powdery scab was first reported in 1954 and was later found in all important potato areas. As it was recently recognized as an important soilborne disease, research has started on the quantification of inoculum.