Growing Magazine - August, 2011

NATIONAL FEATURES

Researchers Release Earlier Pecans

New varieties for growers to consider
By Jenan Jones Benson

Fruit and vegetable growers know it pays to plant the highest-quality cultivars possible, and things are no different for pecan farmers. Orchards planted in the strongest varieties have a high profit potential, but pecans are a high-risk business even with all the best practices in place.


The shell and meat of the Mandan is similar to that of other pecan varieties.

Cultivars that bear fruit at a young age, offer early harvest and/or are disease-resistant are the ones that help keep operations profitable.

Thanks to the United States Department of Agriculture's Agricultural Research Service (ARS), pecan growers have three improved varieties to consider.

U.S. pecan production

Pecan production and marketing dates back to the Revolutionary War. By 1822, improved varieties had been planted in South Carolina. The industry got a shot in the arm with the 1925 introduction of mechanized shelling.

In recent years, organic production has shown growth. ARS studies have demonstrated that organic orchards can outproduce conventional ones by 18 pounds per tree. Many common pests were adequately controlled by such methods as beneficial insect populations and organic insecticides. Scientists believe that several years into organic management growers are less likely to observe alternate bearing tendency, a cycle in which a period of heavy crops is following by lower yields for a time. However, they are continuing to seek a fix for the great pecan foe, scab disease, a fungal pathogen that blackens nuts and can severely damage trees. The bottom line is that organic products command higher prices and the method increases yields, so growers may be profitable despite higher expenses.

Today, the United States is the world's largest pecan producer, believed to furnish 75 to 80 percent of the global supply. Native to southern states including Texas, where it is the official state tree, it is grown throughout the Southeast and Southwest and to a lesser extent, farther north. In 2009, the $2.3 million harvest topped 290 million pounds. Georgia, New Mexico, Texas, Arizona and Oklahoma are the top-producing states. Named for Native American tribes, Pawnee and Mahan are popular varieties. ARS adopted that nomenclature in 1955; the agency has released 28 cultivars since 1953.


The Mandan Pecan, released in 2009 , offers the earliest available harvest
PHOTOS COURTESY OF USDA-ARS PECAN GENETICS AND BREEDING PROGRAM.

Problems with pecans

Although pecan trees are indigenous throughout the South and can survive with little care, commercial growers need an intensive management program to reap good yields every year. The initial investment in developing an orchard must be made five to 10 years, depending upon variety, before the first nut is harvested. Orchards typically show a profit in the ninth year.

Pecans require deep, well-drained soils, and mature trees demand more than 2,000 gallons of water weekly, so proper siting along with irrigation are musts. Soil and tissue testing is vital for proper zinc and nitrogen feeding, and proper spacing and insect, disease and weed control also are vital.

One of the biggest threats is scab disease. Growers in Georgia sometimes spray fungicides up to 15 times a year to control the problem. Pecans also may be susceptible to pecan nut casebearer, powdery mildew and damage by animals such as squirrels.

Developing new varieties

The USDA operates the country's lone pecan breeding program, located in Texas. Its varieties are not patented, so growers can graft and bud their own trees. The agency offers graftwood at no cost to nurseries for propagation and sale.

The process of developing a new pecan begins in the winter when seedling clones are germinated in greenhouses. During the summer, they are examined for scab resistance, a highly desirable trait, in orchard settings. Resistant seedlings are transplanted into orchards on their own roots or budded to pollard trees for a 10-year evaluation period. The best specimens are then tested throughout the pecan growing region. After several years in real-world conditions, the cream of the crop are selected for release as new cultivars.

Since 2007, three new varieties have passed that rigorous testing, dating back to the 1980s, and were introduced.

Lakota expands the pecan growing zone

The 2007 release of Lakota helped expand pecan production beyond the traditional south. It tested well in Kansas, Missouri, Illinois, Oklahoma and Texas. Its high yield potential, early maturity, nut quality and excellent tree strength are likely to make it a popular choice.

The cream to gold-colored kernels split into well-formed, appetizing halves. One pound contains about 59 nuts, which are 62 percent kernel. The vigorous, upright trees have strong limb angles and solid wind resistance. Lakota is not prone to developing scab disease, a plus for southern growers where the fungus is prevalent. It has medium susceptibility to yellow and black aphids that suck sugars and plant nutrients from the leaves and excrete sticky honeydew. This damage from aphid feeding also reduces the flow of nutrients to nuts, significantly reducing yields.

Apalachee offers earlier bearing

One of those cultivars, Apalachee, named for a Florida tribe, meets the need for a pecan that bears fruit at the relatively young age of four years. A decade of trials in Georgia yielded average harvests of almost 1,600 pounds per acre. Apalachee also grew well in Alabama and Texas tests, and proved itself a winner in terms of low propensity to alternate bearing tendency.

Released in 2009, Apalachee kernels are colored in cream to gold shades with narrow ridges and grooves. A small nut well-suited for baking and processing, it weighs out to about 85 nuts per pound. It reciprocally pollinates with such varieties as Lakota, Hopi and Wichita. Nuts mature in early to midseason in late October.

Bred from a cross of the Moore and Schley cultivars, Apalachee trees have central leader growth habits with sturdy limb angles and a wind-resistant structure. It is resistant to scab disease and is moderately prone to yellow and black aphids.

Mandan leads the harvest

Concurrent with Apalachee's release, early-bird Mandan was unveiled. This cultivar is expected to outshine the current first-of-season variety, Pawnee, which matures in early October. Dr. Tommy E. Thompson, an ARS pecan breeder and geneticist at the agency's Crop Germplasm Research Unit in College Station, Texas, says Mandan should be ready for harvest two to four days earlier.

A child of the BW-1 and Osage varieties, Mandan stacks up well against sister varieties Pawnee and Desirable. Texas trials produced harvests of 152 pounds per tree; Pawnee produced 160; Desirable 146. Both Mandan and Pawnee are average-sized nuts, yielding about 51 per pound. The new cultivar is less prone to alternate bearing tendency as compared to these varieties, but thinning may be required. Cream to gold in color, the kernels have medium grooves and rounded ridges.

Because its spring budbreak occurs quite late, Mandan may be grown north of the typical pecan belt. Kanza, Wichita and Lakota cultivars pollinate successfully with it. Trees have a compact columnar growth habit with hardy branch angles, expected to help them escape shading longer than varieties with a tendency to spread. Another big plus is that Mandan is resistant to scab disease, which should save producers many fungicide dollars. It has a moderate susceptibility to yellow and black aphids.

Lakota is available now through nurseries. Both Apalachee and Mandan are expected to be on the market in two to three years.

Learn more about pecan production by visiting www.ars.usda.gov or consulting your local Cooperative Extension Service.

Based in Greensboro, N.C., the author writes articles about horticulture, landscaping, agriculture and travel. She has been a contributor to Moose River Media publications for three years.