Evaluation location: Nebraska, United States
Remnant seed of the original collections was obtained in the fall of 1979 from D. Dewey at the USDA-ARS Forage and Range Research Laboratory, Logan, UT. Seedlings of these strains were grown in cone-tainer seedling tubes in the greenhouse in the winter and early spring of 1980. The seedlings were transplanted into field evaluation nurseries at Mead, NE and Alliance, NE in the spring of 1980. Mead is 35 miles west of Omaha and Alliance is in western Nebraska. The research sites and field and laboratory procedures that were used were described previously by Lamb et al. (1984) in another crested wheatgrass germplasm evaluation study. At both locations, the experimental design was a randomized complete block with two replications. Plots were single rows of 10 plants with rows and plants spaced on 1.1m centers. The crested wheatgrass cultivars Ruff' and Nordan' were used as controls. Hand weeding and herbicides were used for weed control. The nursery at Mead, NE was fertilized with 90 to 112 kg ha-1 N per year in early spring. The Mead nursery was harvested for forage yield for three years (1981, 1982,1983) after plants in the nursery were headed. Forage samples collected from the 1983 harvested were used to determine in vitro dry matter digestibility and forage protein content. Plant height (height to top of spike) was determined on plants at Mead in 1981. Heading date was determined at Alliance in 1981. Stands at Alliance were thin and primarily observation data was collected at that location. Forage yields are reported as grams per plant to correct for differences in plant numbers per plot. . The previous study by Lamb et al.(1984) demonstrated that GxE interaction effects were small for crested wheatgrass in the Central Great Plains and germplasm accessions and cultivars ranked similarly across environments.