Determination of optimum planting procedures for eastern gamagrass (Tripacum dactyloides L.) in a northern climate
Eastern gamagrass has many potential forage and conservation uses in North America and other parts of the world. To date, gamagrass has not been widely grown because it can be difficult and expensive to establish. Since gamagrass is a bunch grass, the stand will not compensate for poor emergence as quickly as sod-forming grasses. Therefore, it is critical to get a full stand immediately. This research investigated the combined effects of planting date, planting depth, and seed stratification on seed germination and seedling mortality of eastern gamagrass to determine methods of maximizing stand establishment in northern regions of its adapted range. Both stratified and unstratified seed were planted at 2.5 and 5.0 cm depths in August, November, April, May, and June of two study years. The August and November planting dates, which mimicked the natural conditions that eastern gamagrass evolved under, produced the greatest final stand densities. Seed stratification was unnecessary for fall planting and decreased final stand density compared to unstratified seed. Seed stratification was a must for early spring plantings of eastern gamagrass. In both years of this study, stratified seed had twice the emergence of unstratified seed in the April and May plantings. Most of the seedlings from June plantings did not emerge until the spring following planting. There were no clear trends in the rate of seedling establishment with planting depth thus it appears that 2.5 to 5.0 cm depth was generally adequate.