Evaluation location: Colorado, United States
There were three replications in each test, which were arranged in randomized complete block designs. Two-row plots were 12 feet long, with 22-inch row spacing and an 8 - to 10-inch within-row plant spacing. The trial was planted on April 20th in Windsor, CO. Inoculation was performed on June 30th and again on July 7th. This evaluation was made on September 14 at the peak of the epidemic. The field was thinned by hand and irrigated as necessary. The 1995 leaf spot epidemic progressed rather slowly at first due to a rain-delayed first inoculation and an unusually cool, wet spring and early summer, but higher temperatures in late July and August, couple with our overhead irrigation to maintain a high canopy humidity, induced a rapid disease advance during the latter part of August. On September 14, means of the resistant and susceptible controls were 3.9 and 5.9 (scale of 0-10), respectively, across the nursery. In 1994 (September 2), these means were 3.3 and 4.8, respectively. Means of contributor lines on September 14 ranged from 3.8 - 7.2, compared with 3.0 - 5.8 in 1994.