Clonal Testing of Elite Eastern Gamagrass [Tripsacum Dactyloides (L.) L.] Germplasm for Forage Quality and in Vitro Dry Matter Digestibility (IVDMD).

Eastern gamagrass is a hearty, long-lived perennial warm-season native grass. The species has many popular uses, the most valuable and applicable of which is as a forage and hay crop. Intense dormancy in eastern gamagrass seed causes delayed germination, emergence, and establishment. Once established, eastern gamagrass is a highly productive, nutritious forage. A total collection of 171 eastern gamagrass individuals was compiled during scouting endeavors throughout the southeast, mid-Atlantic, and Atlantic coast regions from April, 2012 to August, 2012. Stands of eastern gamagrass believed to be native were assessed in situ for stand health before subsequent collection. Samples were harvested as vegetative stem bases (proaxes), transported to Mississippi State University (Starkville, Mississippi), and transplanted into a nursery block in a 1m x 1m grid arrangement at the Henry H. Leveck Animal Research (South) Farm [(33.423756, -88.791594), soil type: Savannah fine sandy loam (Fine-loamy, siliceous, semiactive, thermic Typic Fragiudults)]. Following two consecutive years of analysis for forage quality and suitability, a total of 14 elite individuals were selected for further analysis. Clonal propagules of these individuals were divided and planted in a RCB design with four replications. Forage quality was assessed in separate harvesting events during 2014 and 2015. Entire plants were harvested at a height of 30 cm using a hand-held electric sickle-bar type harvester. Whole plant samples were homogenized and divided into subsamples for analysis. Subsamples were dried in a forced air oven, then ground to pass a 2 mm mesh. All samples were analyzed for IVTDMD in duplicate, according to ANKOM Technology Dietary Fiber Analysis Method 3 using the DAISY^II Incubator. Individual nursery plants showed significant differences (P < 0.0001) in forage digestibility, represented as IVTDMD (LSD = 2.67). Forage IVTDMD values ranged from 50.2%. – 76.3% with an overall mean of 64.5 and a median of 65.2.