Root rot of sweet corn is an important disease of sweet corn in the Willamette Valley of Oregon, first diagnosed in the 1990's. Root rot is caused by a disease complex including Pythium arrhenomanes, Phoma terrestris, and Drechslera spp. Severe root rot was shown to reduce yield in Golden Jubilee by as much as 3 T/A and Super Sweet Jubilee by 1.5 T/A. Root rot also impacts crop quality by reducing ear fill and dimpling corn kernels.
Below are links to the Oregon Processed Vegetable Commission reports and an OSU Extension bulletin describing this disease and its management.
Root Rot of Sweet Corn in Western Oregon. OSU Extension Bulletin # EM 8859 (Powelson and others)
OPVC Research Reports:
Scouting fields for root rot (webpage)