|Brummer, E - IOWA STATE UNIVERSITY|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 20, 2005
Publication Date: October 27, 2005
Citation: Casler, M.D., Brummer, E.C. 2005. Forage yield of smooth bromegrass collections from rural cemetries. Crop Science. 45:2510-2516. Interpretive Summary: Smooth bromegrass is poorly adapted to use in pastures because of slow and limited potential to regrow after grazing. In an effort to find existing germplasm with tolerance to frequent cutting, we evaluated smooth bromegrass plants collected from fence and sod habitats of 30 rural cemeteries in Iowa, Minnesota, and Wisconsin. Populations were tested under three harvest frequencies: four, five, or six harvests over a 2-yr period. Although most cemetery populations had lower forage yield than commercial cultivars, there were a few cemetery sod populations with high forage yield potential, more stable forage yield across harvest managements, and greater regrowth under the more frequent harvest management. Smooth bromegrass germplasm from some cemetery sods appears to have potential value for developing tolerance to frequent defoliation. These results will be of value to other scientists who have an interest in grazing-tolerant forage plants and, eventually, to livestock producers who are interested in planting grasses with better productivity and survival under rotational grazing.
Technical Abstract: Smooth bromegrass (Bromus inermis Leyss) is poorly adapted to management-intensive rotational grazing because of slow and limited regrowth potential. In an effort to discover germplasm with tolerance to frequent cutting, smooth bromegrass plants were collected from fence and sod habitats of 30 rural cemeteries in Iowa, Minnesota, and Wisconsin. The objective of this study was to quantify, describe, and test the responses of paired fence and sod populations to different harvest frequencies. Thirty sod populations, 30 fence populations, and five cultivars were evaluated for season-total forage yield and regrowth percentage at Arlington, WI and Ames, IA. Three harvest managements were used, with mean harvest frequencies of four, five, or six harvests over 2002 and 2003. Fence populations had an average forage yield 5.5% higher than sod populations, a difference that was fairly consistent across harvest managements, test locations, and state-of-origin. Variation in linear responses to harvest management made up 65 and 77% of the harvest management x population interaction for forage yield and regrowth percentage, respectively. For seven cemetery sites, the sod population was better adapted than the fence population to a more frequent harvest management, as measured by a stable response to harvest frequency (-2.02 ± 0.10 vs. -2.67 ± 0.12 Mg ha-1 harvest-1). For nine cemetery sites, the sod population had a higher increase in regrowth percentage with increased harvest frequency (15.8 ± 0.5 vs. 11.9 ± 0.7 percentage units harvest-1). Smooth bromegrass germplasm from some cemetery sods appears to have potential value for developing tolerance to frequent defoliation.