Seeded bermudagrass varieties could someday compete with top-yielding sprigged varieties, according to two years of field research at the Texas A&M University System Agricultural Research and Extension Center at Overton, Texas.
The jury is still out, however, pending at least another three years of tests, said Gerald Evers, forage researcher with the Texas Agricultural Experiment Station.
Since 2002, Evers has been testing experimental seeded bermudagrass lines developed by Charlie Rogers with Seeds West Inc. of Maricopa, Ariz. During 2002 and 2003, some of the experimental lines were as productive as top-yielding sprigged bermudagrass varieties such as Tifton 85.
The tests should be of interest to producers because of the cost difference in establishing sprigged varieties vs. seeded varieties.
Sprigging requires extensive site preparation and a 20-foot long machine - a “sprigger.” Sprigging can cost from $125 to $200 per acre, depending on sprig costs, fertilizer prices and the cost of the actual sprigging operation. Seed varieties, by comparison, can about cost one-half that amount, but existing seeded varieties can't compete with Tifton 85, in terms of yields and digestibility.
Evers has been working with 166 experimental lines, but is cautious about discussing specific experimental lines as seed supplies for testing were limited. He has been limited to working with only two plots — two replications - of each experimental line. To take into account variability in soils and other factors, standard procedure for such variety tests normally calls for four replications.
“With limited seed we just don't have enough replications to talk about yields of specific experimental lines with confidence. We feel good, though, that a dozen or so compare favorably in yield with Tifton 85,” Evers said.
Evers also cautioned with only two years of data, it's hard to rule out variances due weather and other factors.
He did say, though, that in 2002, some experimental lines produced the equivalent of 9,000 pounds per acre, compared with 6,300 pounds for Coastal and 8,900 pounds for Tifton 85. Results for 2003, a wetter year, were comparable with some experimental lines producing well more than 14,000 pounds per acre compared to about 14,000 pounds for Tifton 85 and about 12,000 pounds for Coastal.
Coastal bermudagrass is considered a benchmark crop because it is grown widely throughout the region. Tifton 85 is a relatively new release, but with very high yields and improved digestibility.
Coastal bermudagrass is named for the Georgia Coastal Plain Experiment Station at Tifton, Ga., where it was released by Glenn Burton in 1943.
It now covers 10 million acres in the South. Burton, now in his 90s, also developed Tifton 85, releasing it 1992.
A 2002 Overton center summer grazing study of Tifton 85 showed cattle made average daily weight gains of up to 70 percent more than those grazing Coastal bermudagrass.
Cross top 12
After another year of field trials, the top 12 to15 yielding lines will be crossed. When the crosses are made, there will be enough seed available to do more extensive tests with more replications and other locations, Evers said.
“Then we will have more reliable data and be able to talk about yield performance with some confidence,” Evers said. Evers also emphasized that gross yield isn't the whole story.
“Comparison of establishment-ease, nutritive value, persistence and seed production will be easier and more practical with only 12 to 15 lines,” he said.