Joe E. Brummer, Soil and Crop Sciences, Colorado State University, 1170 Campus Delivery, Fort Collins, CO 80523 and Mark Lamb, Colorado Division of Wildlife, Fariplay, CO 80440.
Fringed sage (Artemesia frigida) is a native plant that has come to dominate many range sites in the South Park Colorado area. Factors such as drought, historic overgrazing, and the transfer/removal of irrigation water have allowed fringed sage to displace the more productive grasses. Fringed sage is low producing, unpalatable to livestock, and is very competitive and persistent once established. The objective of this study was to evaluate various methods of reducing fringed sage followed by reseeding at 3 different times with either a native or introduced grass mix. This study was conducted at 2 sites within South Park. Site 1 was formerly irrigated while Site 2 was a typical upland range site. Fringed sage biomass averaged 1735 and 895 kg/ha in the untreated control plots at Sites 1 and 2, respectively. At both sites, 2,4-D only reduced biomass of fringed sage by 45%. This compares to biomass reductions of 93, 99, and 92% for Cimarron, Curtail, and Tordon herbicides, respectively, at Site 1. Tillage was no better than 2,4-D at Site 1. Control was not as good at Site 2 with reductions in fringed sage biomass of 70, 73, and 81% for Cimarron, Curtail, and Tordon, respectively. At Site 1, grass biomass increased by 215 and 276% in the Cimarron and Curtail plots, respectively, but by only 87% in the Tordon plots. At Site 2, grass biomass increased by 340, 141, 233, and 202% in the Tordon, 2,4-D, Cimarron, and Curtail plots, respectively. Grass establishment was minimal at Site 1. The best establishment at this site was in the tillage treatment. For both seed mixes, establishment was best at Site 2 when seeding occurred in mid-summer. Control of fringed sage allows existing grasses to increase in productivity while seeding in this high-elevation environment appears to be only marginally effective.
