Evaluation location: Texas, United States
The evaluation trial was located near Iowa Park, in the Wichita Falls area of north central Texas (33 59 N, 98 47 W); soil type was a Frankirk loam (fine, mixed, thermic, Udic Argiustolls). The planting consisted of approximately 0.5 hectares and was part of an approximately 2.9 hectare field. One or two plots were planted for all accessions except for the following, which were duplicated three or more times: PI 578687 (intermediate wheatgrass); 97TXB8 (Texas bluegrass); and 97WW2, 97WW3, 97WW4, 97WW5, 97WW9, 97WW18, 97WW20, 97WW22, 97WW26, 97WW27 (western wheatgrass). Plots were grazed only lightly (6 - 17 April and 25 -28 May) by beef cattle in 1998 to allow for establishment and yet prevent seed production; stubble height was greater than 10 cm. Plots were grazed in 1999 from12 - 30 March (545 kg live weight hectare -1), mowed to a height of 10 cm on 9 April, and grazed again from 13 April - 2 June (940 kg live weight hectare -1). Vigor ratings were assigned in early November, 1999.