Writer: Norman Martin
LAS CRUCES - One of the nation's loveliest trees for fall color is the maple, but New Mexico misses out because of an exceedingly dry landscape that prevents the legendary tree from growing well here.
Now, New Mexico State University scientists report that they're on track to develop a drought-tolerant maple that could one day bring splashes of brilliant reds and yellows to a Southwestern yard near you. The prospective maple goes by a curious name, Bigtooth, after the somewhat toothy appearance of the tree's leaves.
"We are looking for a tree that will rival eastern sugar maples in fall color, but is able to grow with limited water," said Rolston St. Hilaire, an assistant professor with NMSU's agronomy and horticulture department.
"The prospect is very appealing," said Curtis Smith, an Albuquerque-based horticulture specialist with NMSU's Cooperative Extension Service. "A lot of people want a maple."
Bigtooth has all the characteristics of a good ornamental tree, St. Hilaire said. It's one of the brightest of the maples. A reengineered, homegrown variety would be a boon to the state's shade and ornamental tree industry.
Bigtooth has a jumbo geographic range. It's indigenous to parts of New Mexico, Arizona, Texas, Oklahoma and Utah. However, it isn't widely used in New Mexico's home or commercial landscapes because the one variety available is difficult to grow.
Attempts to grow the tree from cuttings, a traditional cultivation method, have a success rate of about 1 percent. In addition, the tree only grows well under moist conditions, St. Hilaire said.
Three years ago, NMSU researchers kicked off the Bigtooth project by collecting seed specimens across the Southwest. Seeds from 36 locations were then germinated and grown as seedlings. Along the way, researchers invented a new way of coaxing Bigtooth maple seedlings to grow, using a mix of peat and perlite in equal amounts.
Next came drought studies, designed to find a Bigtooth maple variety better suited for southern New Mexico's harsh growing conditions. "We've tested them under our dry and hot conditions, and found a few promising candidates," St. Hilaire said.
The best experimental trees are now growing in greenhouses and field plots at NMSU's Fabian Garcia Research Center just west of the main campus. Next, scientists will develop tissue cultures and DNA analysis techniques to customize a variety for dry regions.
"This isn't just for New Mexico," St. Hilaire said. "We believe a new maple will be a major addition to the landscaping industry throughout the Southwest."
Bigtooth maple is normally found as a large shrub or small tree growing on moist canyon sides and mountain sites. Its height averages about 35 feet with a diameter of nine inches at maturity, but large specimens can reach 50 feet. Bigtooth leaves have the famous maple-shape - think of the Canadian flag - with three to five lobes.
The maple is one of America's most loved trees, especially in the fall. With variety names like Red Sunset and Autumn Flame, the tree's brilliant colors range from scarlet to golden yellow. Known for its hard, strong wood, maples are often associated with New England, but the United States has 13 native maples, with at least one species native to every state except Hawaii.
Bigtooth maples are closely related to the eastern sugar maple, said St. Hilaire, who has experimented with maples at NMSU and Iowa State University for 10 years. The sap in both can be boiled down to make syrup or sugar. However, Bigtooth, as a smaller tree, isn't an economical syrup producer, he said.
St. Hilaire cautions that a drought-tolerant maple variety won't be available overnight. While several promising specimens have been selected, a new tree for New Mexico is probably more than a decade away. "These are relatively slow-growing trees, not row crops," he said. "It's a long-term effort, but one that has tremendous economic potential."
Plus, there's the promise of stunning red and yellow trees sweeping across the landscape each fall for future New Mexicans, he said.
© 2013 New Mexico State University Board of Regents
NMSU - All About Discovery!