Fungi Associated with Common Root Rot of Winter Wheat in Colorado and Wyoming. J. P. Hill, Assistant Professor of Botany and Plant Pathology, Colorado State University, Fort Collins 80523. J. A. Fernandez, Assistant Professor of Plant Pathology, and M. S. McShane, Former Graduate Student, University of Wyoming, Laramie 82071. Plant Dis. 67:795-797. Accepted for publication 27 December 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-795.

Winter wheat plants were sampled during two growing seasons in Colorado and Wyoming to identify fungi associated with common root rot. Isolates derived from diseased wheat were grown in pure culture and screened for pathogenicity. Of 852 fungal isolates tested, 408 were pathogenic to seedling wheat and most were identified. Of the screened isolates, 139 (34%) were Bipolaris sorokiniana and 225 (55%) were Fusarium species, of which 113 (28%) were F. roseum ‘Acuminatum.’ In fall and early spring, B. sorokiniana was usually the fungus most frequently isolated. Both B. sorokiniana and F. roseum ‘Acuminatum’ were usually isolated from diseased tissues from early summer to crop maturity. B. sorokiniana and F. roseum ‘Acuminatum’ are considered primary components of the common root rot complex in Colorado and Wyoming.

Keyword(s): foot rot.