Value of Rapid Initial Assessment of Native Grasses from Arizona for Potential Turf Type Growth.

In the southwestern U.S. there is increased demand for more efficient water use and increasing reluctance to use non-native plant species in landscapes. Our research involves collection and evaluation of native grasses from southern Arizona that have persisted in areas with long-term livestock grazing. This report addresses the relationship between easily assessed traits in greenhouse-grown plants and initial performance after a simulated grazing event. If effective, rapid assessment of the phenotype in greenhouse-grown plants could greatly improve the efficiency of germplasm screening projects for developing turf-type native grasses for the  species below.   In 2007, over 250 clones from six species (Hilaria belangeri (Steud.) Nash, Cathestecum erectum Vasey and Hack, Bouteloua chondrosioides (H.B.K.) Benth. Ex S. Wats., B. hirsuta Lag., B. gracilis (H.B.K.) Lag ex Griffiths, and Lycurus setosus (Nutt.) C. Reeder) were collected and assessed in a greenhouse trial. Plant width and height, and visual assessments of turf density and quality (scored using five classes), were assigned both before and 28 days after a single clipping event.   Species with the highest mean scores for quality and density included the stoloniferous grasses of Cathesticum > Hilaria, followed by the buchgrasses of Lycurus > Bouteloua chondrosoides.  Plant height/girth ratios were not always related to quality and density visual values, suggesting that vertcial elongation rates may be different between and within species.  Independent culling levels selection was used to eliminate 25% of the accessions from each species. Initial culling was based on retention of clones with the highest mean turf quality and density both before and after clipping, followed by as second cull based on retaining clones with the lowest mean plant height/width ratios before and after clipping.