Growth Performance Comparisons among 18 Accessions of Fourwing Saltbush (Atriplex canescens) at Two Sites in Central Utah

Abstract

Growth characteristics of 17 accessions and 1 selection of fourwing saltbush (Atriplex canescens [Pursh] Nutt.) at 2 sites in Sanpete Valley, central Utah, were scored on 6-year-old mature plants. There was no difference in survival at the 2 sites, but plants at the Snow Field Station near Ephraim grew taller, were more vigorous, and exhibited more reproductive capacity than those at the Peacock Plot near Manti. The plants at Peacock Plot had a more upright growth habit, were more uniform, and exhibited less insect and disease damage than the Snow Field Station plants. A composite quality index (QI) revealed highly significant site and accession differences but little site × accession interaction. The individual traits (height, growth habit, uniformity, vigor, reproduction, and insect and disease damage resistance) all showed significant site effects and site × accession interaction. An accession and its selection from Rincon Blanco, Rio Arriba County, New Mexico, performed well at both sites. Also performing well at both sites were a local accession from Excell Canyon, Sanpete County, Utah, and the gigas accession from the Little Sahara Sand Dunes, Juab County, Utah. In general, accessions from elevations higher than the test sites performed best. Accessions with high QI's are recommended for revegetation plantings of sites comparable to the 2 study sites. The Rincon Blanco material has good growth characteristics and may also be broadly adapted.