A new pecan variety that promises to greatly mitigate alternate bearing should be available in limited supply to growers in Arizona, California and New Mexico next year.

Developed by USDA Agricultural Research Service scientists based in College Station, Texas, Mandan was released to nurseries for propagation last year. It should be more widely available in 2012.

It offers growers high nut quality, high yield potential, early nut maturity, excellent tree strength and late bud break. Also, Mandan is very resistant to scab disease with medium susceptibility to yellow and black aphids. It should be adapted to any area of the world where pecan trees grow. Mandan nuts can be sold in-shell or shelled to produce a large proportion of halves and large pieces.

During 11 years of extensive testing, Mandan produced about 152 pounds of nuts per tree, compared to 160 for Pawnee and 146 for Desirable varieties. Both Mandan and Pawnee produced about 92 pounds of kernels per tree, while Desirable produced 75. Mandan had 2.3 nuts per cluster. That compares to 3.3 nuts per cluster for Pawnee and 2.7 for Wichita. Nut size (nuts per pound) averaged about 51 for Mandan and Pawnee, 48 for Desirable and 58 for Wichita. Mandan nuts shelled out with about 60 percent kernel. That was higher than Pawnee, Desirable and Wichita.

Mandan nuts mature about 4 days earlier than Pawnee and around 30 to 35 days earlier than Western Schley. That’s particularly significant in reducing the alternate bearing tendency of pecan trees, notes research geneticist Tommy Thompson. He and his colleague, L.J. Grauke, led development of Mandan.

The sooner the nuts mature, the sooner they quit taking nutrition from the tree. “This allows more time for the leaves to produce energy needed for nut production which is stored over the winter in the tree’s roots,” Thompson explains. “That can enable the tree to come back with a larger crop of nuts the next season for more consistent production from one year to the next.”

The early nut maturity of Mandan also means that southwestern growers can harvest and market their nuts sooner in the fall to take advantage of the higher prices paid for nuts sold to meet the higher demand at Thanksgiving and Christmas.

“In central Texas, some of the bigger growers give up the 50-cent or so premium for early season holiday sales because their current pecan varieties can’t be harvested in time for this market,” Thompson says.

Also because Mandan doesn’t leaf out as early as Pawnee, Western Schley and other varieties, it’s less susceptible to frost. Thompson also notes that Mandan, and all USDA pecan varieties are not patented and can be budded and grafted as much as desired.