What is in this article?:
- New Lipan pecan variety offers good yield, disease resistance
- Pecan breeding process
- The new pecan variety Lipan - released as a trial variety by USDA-ARS last July - is a large, high-quality nut which generates excellent yields and improved disease resistance.
- The Lipan pecan should make money for growers, says USDA-ARS pecan breeder Tommy Thompson.
- Thompson bred the Lipan variety - Carya illinoinensis - at ARS' pecan breeding and genetics laboratory in College Station, Texas.
- Graft wood has been released to 35 nurseries across the U.S.
Pecan breeding process
The four-phase pecan breeding process requires about 20 years to bring a potential variety from laboratory and field testing to commercial production.
Phase one is the seed-production phase where plant crosses are created from male and female breeding parents. From 200 to 1,000 seed (clones) are developed the first year. The nuts of known parentage are planted in greenhouse containers at the ARS pecan-breeding facility in Brownwood, Texas around Christmas and then transferred to the ARS’ College Station breeding facility in April.
During phase two, clones are grown in pots under scab-infected trees for one year to screen for resistance to pecan scab disease. This process is extremely effective in weeding out lower-resistant crosses.
The trees are rated and the leaves stripped off several times. About two-thirds of the seedling trees are eliminated due to low-scab resistance.
“Lipan has good levels of scab resistance,” Thompson said. “Scab resistance is especially needed in Southeastern U.S. pecan orchards. We try to plug in genetic resistance into new varieties. The resistance lasts a long time, and pays the grower back each season through reduced or no sprays to control the disease.”
Genetic resistance to fruit scab also controls leaf scab.
“When we get resistance in the new seedlings, we know these clones will also be resistant to nut or fruit scab,” Thompson said. “This disease can be controlled in many pecan-growing areas simply by planting resistant varieties.”
In phase three, the best seedling clones are established on their own roots or budded to pollarded (hedge-trimmed) trees for eight years of testing at College Station.
Three years of nut production are needed to determine if a clone has good nut production and quality potential, excellent tree characteristics, scab and insect resistance, and other factors.
“A new pecan variety must produce better resistance than the standard varieties. If not, the variety is not released for commercial production,” Thompson said.
In phase four, superior clones enter the National Pecan Advanced Clone Testing System, or NPACTS, for 12 years. The clones are tested across the U.S. Pecan Belt from northern California in the West to the Carolinas in the East in cooperation with federal and state researchers and private growers.
After several years, the best clones are released to nurseries for propagation to sell to producers. The best or standard varieties for each particular region are planted in these tests for comparative purposes. Again if the (clones do not outperform existing standards, the clones are not released.
Lipan passed the 20 years-plus of tests. Thompson is optimistic that Lipan will become a successful variety for commercial pecan producers.
“We think Lipan will be a solid performer,” Thompson concluded. “The true test is how it will perform for growers over the next few years.”