No variety is completely resistant, but some of the newer lines are more tolerant.
Diseased seedlings have dark brown spots near the seed or on stems below the soil line.
Crown rot develops later in the season. Affected plants may turn prematurely white. Kernels in the head are shriveled and roots are dark brown and rotted. Yields often are reduced by root rot even though symptoms are not well developed. Promote rapid emergence by planting in well prepared, warm seed bed.