VIEW ARTICLE

Survival of Phoma betae in Soil. W. M. Bugbee, Research Plant Pathologist, U.S. Department of Agriculture, Agricultural Research Service, Department of Plant Pathology, North Dakota Agricultural Experiment Station, Fargo 58102; O. C. Soine, Professor, University of Minnesota, Northwest Experiment Station, Crookston 56716. Phytopathology 64:1258-1260. Accepted for publication 13 May 1974. DOI: 10.1094/Phyto-64-1258.

In field plots, the highest numbers of propagules of Phoma betae were found in April of the first year following sugar beet culture. Soils were sampled from naturally infested plots of six crop rotations used in this region. The fungus was recovered as long as 26 mo after sugar beets had been planted, but not in the third year following sugar beets. Phoma betae invaded the roots of lambsquarters (Chenopodium album) growing in cultivated fields and sugar beet storage yards. The fungus rarely invaded the roots of oats. The fungus was present in soil from sugar beet storage yards throughout the Red River Valley of North Dakota and Minnesota. Populations decreased during the summer, but the fungus was still present when roots from the new crop were being stored.