Cereal rusts and bacterial leaf streak appearing in wheat
Bacterial leaf streak was another disease noted in some of the surveyed wheat fields. Bacterial leaf streak was between low to moderate severity for most fields except fields that had hail damage. These fields seemed to have elevated severity of bacterial leaf streak. If the bacterial infects the wheat heads, it causes black chaff, where the wheat head becomes brown-black with necrotic streaks and blotches mainly on the glumes. This disease cannot be managed by applying fungicides! Use of clean seed and resistant/tolerant cultivars are the recommended management practices.
Leaf spot diseases (tan spot, septoria/stagnaspora blotch) were mainly found in the mid-to-lower canopy in most wheat fields. The pathogens that cause these leaf spot diseases survive on residues and require wet conditions for infection to occur. Dry periods like we are having currently prevent new infections and lesion expansion to occur. The fungal leaf spot diseases can be managed effectively through wheat residue management and through use of fungicides. Fig. 5. Severe bacterial leaf streak in a winter wheat screening nursery at Brookings on June 30, 2013.