Small Grains Disease Update

Nathan Kleczewski, Extension Specialist – Plant Pathology;

Diseases are starting to develop in wheat and barley, although overall levels are low. Spot blotch, Septoria blotch, and Stagonospora blotch have been observed in the field and in the clinic. Stagonospora and Septoria blotch can be easily confused. Look for the following:

Stagonospora blotch: Lesions are often lens shaped. Black structures are rarely seen in these structures.

Septoria blotch: Lesions are often observed as specks or long, thin lesions. Black structures are often prominent within these lesions.

Also, there have been some reports of powdery mildew building in some fields of wheat and barley. Caution must be observed with powdery mildew as it can develop and spread rapidly, particularly on highly susceptible cultivars.

The recent wet weather likely will increase the incidence and severity of these diseases where they are present. Keep an eye on the weather and disease development as plants approach Feekes 8-9. Extra caution is advised if you are using a highly susceptible variety. Check with your seed dealers or variety trials published at UD and UMD for information on disease susceptibility.