OVERTON - Lablab, a drought-tolerant, summer annual legume native to the tropics, could be a valuable addition to the Texas forage repertoire, according to a Texas Agricultural Experiment Station scientist.
"An accelerated lablab breeding and evaluation program will start for this summer to provide improved cultivars for both livestock and wildlife management systems in Texas," said Dr. Ray Smith, Experiment Station legume breeder based at the Texas A&M University System Agricultural Research and Extension Center at Overton.
Forage scientists have had lablab on their radar screens for some time. The tropical legume forage can be grazed, cut as hay or grown in mixtures with corn or sorghum and harvested as silage. It can produce nearly 2 tons of dry forage per acre in 100 days with leaf protein content as high as 25 percent. It's not known how much lablab is grown in the United States, but most seed is currently imported from Australia.
"Lablab has about the same forage production and nutritive value potential as Iron and Clay cowpeas," Smith said. "Compared to bermudagrass, it's generally going be higher in protein."
But while cattle don't like cowpeas, they find lablab forage highly palatable. White-tailed deer, which can be picky eaters, will also browse lablab, making it a good, low-management crop for supplemental feed in wildlife plots.
It can be grown in various environments throughout the Southeastern United States and thrive on as little as 10 to 15 inches of rainfall during the growing season. And as do all legumes, lablab can fix nitrogen from the air where forage grasses need supplemental nitrogen. The price of nitrogen fertilizers, tied to the costs of oil and natural gas, is rising. So an alternative high-protein forage legume such as lablab could make sense both economically and environmentally, Smith said.
More importantly, there's also the possibility of it becoming a value-added seed crop for the region's farmers, according to Smith. "These characteristics and our experiments with palatability indicated a need to develop new cultivars of lablab that could better tolerate Texas heat and drought," said Smith, who developed Apache, an arrowleaf clover resistant to bean yellow mosaic virus.
Smith, working with Dr. Monte Rouquette, Experiment Station forage physiologist also based at the Overton center, evaluated 42 breeding lines of lablab for regrowth after grazing, relative maturity and seed production potential.
"All entries had excellent regrowth following grazing, but we noted wide differences in time of flowering," Smith said. Flowering time varied from late summer to late fall. In much of Texas, the late-fall flowering varieties would probably mature too late to produce viable seed, he said.
Smith selected the most promising lines and grew them for seed in a greenhouse. From the greenhouse trials, he identified three elite selections for further seed increase.
The three were planted at Vernon in mid-June 2003.
"We planted in Vernon because it is a drier climate. We're interested in finding an alternative seed crop for Texas growers, and drier, less humid climates are more conducive to producing a higher-quality, disease-free seed crop," Smith explained. Two of the three lines had excellent seed production, and Smith plans to continue evaluating both this year, but he cautions that developing a new variety takes some time.
"It will take three to five years of research to develop a new variety of lablab that will be a useful forage and seed crop," Smith said.