Interrelationship of Cultivar Reactions to Common Root Rot, Black Point, and Spot Blotch in Spring Wheat. R. L. Conner, Crop Sciences Section, Agriculture Canada Research Station, Lethbridge, Alberta T1J 4B1. . Plant Dis. 74:224-227. Accepted for publication 3 October 1989. Copyright 1990 Department of Agriculture, Government of Canada. DOI: 10.1094/PD-74-0224.

The reactions of 18 spring wheat cultivars to common root rot, black point, and spot blotch caused by Cochliobolus sativus were determined in a series of controlled-environment studies. No strong correlations were detected for reactions to these diseases. However, a weak negative correlation was detected between black point and spot blotch ratings. Large differences in disease reactions were observed among cultivars for each disease. No cultivar was resistant to all three diseases, but the cultivar Rescue was universally susceptible. The cultivars Owens, Sinton, Neepawa, and 7825-J3D were rated most resistant to common root rot. The hard red spring wheats were uniformly susceptible to spot blotch, but the soft white spring wheat cultivars Fielder, Owens, and Dirkwin were resistant. Cadet and Glenlea consistently had the lowest incidence of black point.