- Lablab readily grazed by cattle, wildlife.
- New varieties could be more disease resistant.
- New cultivars released in three years after field tests.
THE value of lablab, an annual tropical legume, as potential quality forage has long been known, but the value still can be improved, according to Texas A&M AgriLife Research plant breeder Dr. Gerald Smith.
Smith, who is based at the Texas A&M AgriLife Research & Extension Center in Overton, Texas, is currently working with hundreds of crosses in search of superior qualities.
"We need a new forage crop in Texas that fits our seasons and works for us in the summer," Smith said. "We have a lot of summer annual grasses, but we need a forage legume that works in the summer like those grasses."
Lablab (Lablab purpureus [L.] Sweet) fits that need very well, he said, explaining that it is a great crop for cattle, which readily graze it and get good weight gains on it. Lablab also is drought tolerant.
It's also a great plant for wildlife browsing, particularly for white-tailed deer, Smith said. As an added benefit, lablab, being a legume, fixes nitrogen from the air, which offsets high fertilizer prices, he noted.
Unlike many other legumes, such as cool-season clovers, lablab seed can be produced in Texas.
"Lablab is deep-rooted and drought and heat tolerant but does require soil moisture to germinate and establish," Smith said. "This does narrow the utility of this plant to eastern and central Texas, where annual rainfall is at least 30 in. per year."
Because of all of these benefits, Smith has been working with lablab lines for the last 10 years. Rio Verde lablab, which Smith developed at the Overton center, was released by Texas A&M AgriLife Research in 2006.
Planted in May, Rio Verde will start flowering in late August and will continue producing forage until the first frost. The crude protein content is 25% or more in its leaves and 12% in the stems.
Still, there is a need for an earlier-flowering and more disease-resistant variety, which Smith said he is continually working on.
From the hundreds of second-generation crosses he currently has in the Overton greenhouses, Smith is looking for types that not only have improved disease resistance and drought tolerance but also demonstrate other traits such as small seed size, early flowering and seedling vigor. All of these traits will fit better into Texas forage production systems.
To this end, Smith has crossed existing anthracnose-resistant lines with small-seed, deep-rooting types that are closely related to "wild" lablab lines.
"The parents that we crossed are quite different," he said. "What we are doing now is selecting for flowering times that will fit Texas."
Next, he'll take the most promising progeny to field tests in 2013 and further select for desired traits.
If all goes well with field tests, Smith expects new cultivars to be ready to start the release stage in three years. The approval and subsequent release of seed to seed production companies usually takes an additional two years.