University of Illinois

No. 5/April 25, 1997

Karnal Bunt: The Saga Continues

Karnal Bunt: The Saga Continues

There is still a lot of confusion and concern relating to exactly how damaging Karnal bunt disease is throughout the United States. Recently, surveys have shown that many of the suspected infestations are not Karnal bunt but a ryegrass smut or bunt that closely resembles Karnal bunt when viewed under a microscope. Only through laboratory testing can the two fungal spores be differentiated. It turns out that many of the positive samples in the southern states were actually spores produced on ryegrass, which is commonly found in southern wheat-producing areas and not true Karnal bunt. So, the true extent of the infestation beyond the original areas of the Southwest is still not fully known.

We will continue to sample during this season. However, the program will be scaled back considerably because we did not detect Karnal bunt this past year. However, the USDA will sample states for at least another season to collect more baseline data on this disease and determine the best method of managing Karnal bunt infestations. Plant pathologists do not consider this pathogen to represent a major threat to wheat production when compared to our common diseases.

Walker Kirby, Department of Crop Sciences, (217)333-8414