Submitted to: Trade Journal Publication
Publication Type: Trade Journal
Publication Acceptance Date: 7/20/2006
Publication Date: 9/21/2006
Citation: Myers, M.W., Adler, P.R., Curran, W.S. 2006. Switchgrass: establishment and weed management. PA Project Grass. 4(6):18-20.
Interpretive Summary: Not required.
Technical Abstract: Switchgrass is a tall growing, native, warm-season, perennial grass which can grow on marginal lands. Lately grabbing a lot of attention for its biomass fuel potential, switchgrass has been used for years in livestock forage production systems. Once established, switchgrass is relatively easy to manage, can be high yielding with few fertility inputs, and does not have many pest problems. The key to a good stand however, is proper management during the year of establishment. Important factors influencing a good switchgrass stand are proper seeding rates and planting dates, correct seeding depth, and weed control. Grassy weeds are more of a challenge to control in new switchgrass seedings versus broadleaf weeds. Several herbicides on the market may provide selective grass control but few studies have evaluated their potential. A study was conducted at the USDA research farm at Rock Springs, PA in 2005 to investigate the effect of quinclorac and other herbicides on weed control and switchgrass seedling injury. All herbicide treatments were applied postemergence when the switchgrass was 3-4" tall with 3 leaves. Weeds of interest at the time of application included common lambsquarters, redroot pigweed, fall panicum and witchgrass, and both yellow and green foxtail. Quinclorac alone provided good control of the foxtail species and quinclorac plus dicamba offered a good broad-spectrum combination by controlling both the foxtail and broadleaf species. All treatments did show some signs of switchgrass injury within one week after application but the injury quickly disappeared. These results suggest that grassy weed control is possible with the introduction of new herbicides to the market.