Blotch Symptoms Infected glumes develop gray-brown blotches usually starting at the tips of the glumes. Pycnidia are the source of infectious spores. Visible with a 10X lens, pycnidia on discolored glooms are the best sign of this disease. Infected heads develop low test weight due to shriveled grain. Cause Glume Blotch is transmitted by fungal spores of Stagonospora nodorum that blow or splash onto wheat heads.
Spores usually originate from diseased foliage or infested wheat stubble.
See the page on Leaf Blotch Complex for more information. Infections occur during periods of extended wetness. IPM Techniques Plant moderately resistant varieties. Avoid nitrogen excesses and deficiencies. Annual Kentucky Small Grain Variety Trials, Progress Report 355 Selecting Wheat Varieties, Grain Gleanings, Vol.