Common Root Rot and Scab

This disease causes roots and crowns to darken and develop poorly. Spikes turn white before healthy plants begin to mature. Heads and kernels do not fill normally. Plants are usually stunted and produce few tillers. Infected heads turn white; pink or orange fungal mycelium develops on the surface of bleached spikelets.

Scab is caused by strains of the same Fusarium species that cause root rot. The fungi survive on host residue and in soil as mycelia and resting spores and are favored by warm weather. Water stress intensifies the disease in infected plants. Root and crown tissues are infected if conditions are wet or warm enough to allow fungal growth. Spores splash onto spikes and infect flower parts if they remain continually wet for several days.

Cultural Control

Plant late in the fall to avoid excessively warm soil conditions. Follow best management practices for nitrogen fertility. Irrigate to avoid water stress. Rotate out of small grains.

Chemical Control

No fungicide treatments are recommended for this disease.