Wheat Head Scab
Wheat Head Scab
Symptoms
Fusafium head blight (Head Scab)
University of KY Dept. Plant Pathology
Individual spikelets or groups of spikelets turn cream to white on otherwise green heads. Entire heads may become diseased when extended periods of warm, wet weather occur during flowering and early grain fill.
Pinkish-orange patches of fungal growth may be seen at the base of infected spikelets. Infected spikelets often fail to develop grain, or grain is extremely shriveled and of low test weight. Shriveled grain may have a pinkish color.
Cause
Scab fungi overwinter in cereal, grain sorghum, and corn stubble and in soil. Spores are produced and heads become infected when warm, wet weather occurs during the flowering period for wheat. During most years, most fields escape serious infection because flowering does not occur during warm, wet weather.
IPM Techniques
Nature provides the best management by limiting disease-favorable conditions during crop flowering. No chemical controls exist, and all wheat varieties are susceptible. However, planting two or more wheat varieties on your farm will decrease the chance of head scab by altering flowering dates and reducing chances that all your wheat acreage will be involved in a head scab epidemic. Planting wheat after corn or grain sorghum, especially no-till plantings, or not properly rotating fields out of wheat, encourages head scab development. Alternative production practices, however, do not preclude a severe head scab epidemic from developing. This is because of the widespread occurrence of the causal fungi throughout Kentucky soils.
References and Additional Information
- IPM-4 Kentucky IPM Manual for Small Grains
- PPA-10c Kentucky Plan Disease Management Guide for Small Grains by D.E. Hershman and Paul Vincelli
- PPA-38 Head Scab of Small Grains in Kentucky by Donald E. Hershman
- Common Diseases of Small Grain Cereals. F. J. International Maize and Wheat Improvement Center, Londres 40, Apdo. Postal 6-641, Mexico, D.F., Mexico
- Compendium of Wheat Diseases, M.V. Wiese, The American Phytopathological Society Press, 1987.
