Brad Johnson column: Eastern Gamagrass a good plant

Published 12:00 am Friday, August 26, 2011

By Brad Johnson
For the Salisbury Post
SALISBURY — I recently had a question from a producer in the western part of the county to identify a pasture grass.
The grass looked familiar. The seedheads were especially unique and made me think it was probably Eastern Gamagrass, but the plant itself was a giant bunch grass that was easily 6 feet tall. I vaguely recalled learning about Eastern Gamagrass in forage classes in college, but that was more than a couple years ago and hadn’t seen any since then, so I didn’t recall the plant being so large. Taking a sample back to the office and doing some research, sure enough, it was Eastern Gamagrass. Good stuff.
Some background about Eastern Gamagrass: I strongly remember the forage class professor describing Eastern Gamagrass as an “ice cream plant.” It’s a very high quality, nutritious grass, but is very challenging to establish. According to information from the University of Missouri, Eastern Gamagrass (Tripsacum dactyloides) is a warm season bunchgrass native to the Eastern United States.
This highly productive grass is best adapted to wet habitats and is commonly found in flood plains and along stream banks. Individual grass clumps can reach a diameter of 4 feet with seed heads growing to be 3 to 9 feet tall.
Tradition has it that Eastern Gamagrass was regarded as a high-quality forage crop by early settlers, but native stands were destroyed to produce grain crops or were grazed out by livestock.
The native animals (buffalo and elk) that used this grass before European settlement were herd animals that grazed and then moved to fresh grass, not returning to an area they had grazed until plants had an opportunity to regrow. This rest period is critical to the survival of bunch grasses, because they rely on carbohydrates stored in the leaf bases for regrowth.
If animals are allowed to graze regrowth before carbohydrates can be stored, plants will soon succumb to overgrazing. This is why rotational grazing has become so important in modern production.
Eastern Gamagrass produces the majority of its growth from mid-April through mid-September. Eastern Gamagrass begins growing earlier in the spring than do the other native warm season grasses, such as Big Bluestem or Switchgrass.
One of the major problems associated with Eastern Gamagrass is difficulty with establishment and poor seed production, resulting in high seed cost. Recent developments in breeding Eastern Gamagrass varieties with higher yields of good-quality seed have resulted in improved seed availability and lower prices. Three cultivars of this type available commercially are: Pete, PMK-24, and IUKA.
Eastern Gamagrass seed exhibits seed dormancy that is overcome by prolonged chilling. Stratification, or wet-chilling of seed at 35 degrees for 10 weeks before planting, improves germination dramatically. The two most commonly used seeding techniques at present are:
• Plant stratified seeds when soil temperatures reach 65 degrees in April-May.
• Plant unstratified seed in the winter (November to February) and rely on natural soil temperatures to break seed dormancy.
Both stratified and dormant seed are readily available through commercial seed sources.
Eastern Gamagrass yields of more than 6.5 tons of dry matter per acre have been recorded. This highly productive, nutritious grass can be grazed, harvested for hay or put up as silage. As with all grasses, the quality of Eastern Gamagrass forage declines as plants mature. The boot stage of development results in the least amount of fiber and highest protein, after which forage quality declines significantly.
Forage removal as hay or silage should be taken before the boot stage, when plants are 24 to 36 inches tall. Grazing can begin earlier, when plants are 18 to 24 inches tall. An 8-inch stubble should be maintained to ensure that adequate leaf base material is present to support regrowth. Harvests of regrowth can be made four to six weeks after the initial harvest.
If grazed, a rotational stocking system should be used and ideally a 10-inch stubble should be maintained.
Producers planning to re-seed cool season pastures (tall fescue, orchardgrass, and cool season legumes) are approaching the ideal time of year, late August-mid-September. Some questions to think about to hopefully ensure the best possible stand:
• Have you taken soil samples of the pasture to be re-seeded?
• Have you fertilized and limed as indicated on the soil test report?
• Have you purchased certified seed?
• Is the seeder/drill set up properly?
• Have you properly controlled weeds or are you prepared to control weeds?
Brad Johnson, Extension agent, agriculture-livestock and dairy, Rowan County Cooperative Extension, 704-216-8970.