Evaluation location: North Dakota, United States
Fifteen plants (three replicates of five plants) were inoculated with race 3 rust spores mixed with Soltrol 160 mineral oil. Plants were evaluated on the basis on percent leaf area covered with pustules and grouped into the following categories: 0, 0.1, 0.2, 1.5, 1.0, 2.0, and 5.0% leaf area covered. Plants with 0.5% or less of the foliage covered by rust were classified as resistant. For accessions classified as resistant 15 plants (in some cases more than 15) were retested. The total number of plants tested for the accessions with a high percentage of resistant plants is between 30 and 40 plants.