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The Center for Native Grasslands Management

Title: Switchgrass establishment during the dormant season and with winter annuals: Preliminary evaluations
Year: 2010
Author(s): Keyser, P., Allen, F., Bates, G., Rhodes, N., Harper, C., Doxon, E., Goddard, K.
Source Title:
Source Type: Proceedings
pages: 33
Original Publication:  
Abstract: Establishment success of switchgrass has not been consistent. Failures are often linked to seed dormancy, a common trait in this species. One strategy for breaking dormancy is dormant‐season planting, but success of this approach has not been well documented. Because of allelopathy of winter annuals, planting into them has been suggested as both a solution and a potential problem, but regardless, the approach has not been documented. We initiated two experiments in Tennessee to evaluate these establishment methods. In the first experiment, we planted switchgrass in December 2008, February, March, and May 2009 (whole plots) using high- and low-dormancy seed lots at 6 and 9 lb/ac rates (split plots) at two sites. In the second experiment, we planted switchgrass in March, May, and June 2009 (whole plots) into four winter annuals (wheat, oats, cereal rye, and barley) and a fallow control (split plots) at three sites. Neither grass height nor weed height differed among planting dates for experiment one (dormant planting) for the two locations. Switchgrass frequency was differed, but overall success was low and patterns between the two locations were not consistent (Mar = May > Feb = Dec at one location; Dec = Feb = Mar > May at the other location). Seed dormancy levels and seeding rates did not affect establishment success. In experiment two (winter annuals), results also varied by location with May plantings better (greater frequency and height of switchgrass) at one location, June plantings better at the second, and dates similar at the third location. However, regardless of date, overall establishment success in experiment two was much better than in experiment one (approximately 40% vs. 10% frequency or 3.8 vs. 0.9 plants/ft2). Among the winter annual treatments, oats and wheat appeared the best choices among the three locations (P <0.09) and none proved to be a problem. A second year of the experiment is now underway and biomass yield figures will be collected on second-year stands.
Publisher: Proceedings of the Seventh Eastern Native Grass Symposium. Knoxville, TN, October 5-8, 2010
Editor(s): C. Harper