Distinguishing Between the Loose Smuts of Barley. P. L. Thomas, Agriculture Canada, Research Station, 195 Dafoe Road, Winnipeg, Manitoba R3T 2M9. Plant Dis. 65:834. Accepted for publication 29 December 1980. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1981. DOI: 10.1094/PD-65-834.

Ustilago nigra and U. nuda are difficult to differentiate in barley in the field because biotypes within each species produce different morphological types of infected spikes. The most reliable distinguishing feature is the sporidial germination type of U. nigra as opposed to the mycelial germination type of U. nuda.