Tree Improvement and Genetics

Ensuring the supply of high-quality loblolly pine seedlings for regenerating harvested plantations is a critical effort. Studies have shown that every 0.1% increase in growth achieved by tree improvement has an impact of approximately $14 million on Virginia’s economy. The DOF supports the ongoing selection, testing, and deployment of the best loblolly, shortleaf, eastern white, and longleaf pine seedlings for Virginia citizens. Our tests involve comparisons of new open-pollinated and control-pollinated seedlings. We are currently in our fourth generation of progeny tests in collaboration with the North Carolina State University Tree Improvement Program and planning is underway for the fifth generation of selection, breeding, and testing.

What Does Tree Improvement Mean?

Prior to tree improvement, loblolly seeds were collected from “unimproved” natural stands – mostly from trees felled during logging operations. In 1956, the North Carolina State University Industry Cooperative Tree Improvement Program was created. Our objective as a co-op member is to select, breed, test, and deploy trees that result in economic benefit to Virginians. The result of nearly 65 years of that effort is loblolly pine seedlings that grow nearly twice as fast as the original unimproved stands.

Ongoing Projects

Tree improvement is still primarily driven by installing large-scale field studies to compare the growth and health of selected families of trees. This involves two to four of these “progeny” tests each year. In addition, there are studies to determine better seed production methods and to look for faster ways to make new selections (i.e., to shorten the time it takes to get better seedlings in the hands of Virginia’s landowners).


Additional Resources

ImageTitleIDDescriptionContent TypeViewhf:tax:document-categoryhf:tax:Media
An Assessment of Potential of Hybrid Poplar for Planting in the Virginia Piedmont
An Assessment of Potential of Hybrid Poplar for Planting in the Virginia Piedmont

Report provides four-year results from a study of 12 hybrid poplar clones planted in replicated yield trials at two locations in the Virginia Piedmont. Results through the first four growing seasons showed that the clone with the most rapid height growth was also most susceptible to frost damage and stem canker disease. Harold E. Burkhart, Amy M. Brunner, Brian J. Stanton, Richard A. Shuren, Ralph L. Amateis, Jerre L. Creighton.

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DOF Pine Seedlings are Top Choice - Genetically-Improved Seedlings Explained
DOF Pine Seedlings are Top Choice – Genetically-Improved Seedlings ExplainedFT0001

Forestry topic information sheet details why Virginia trees are your best choice, including cooperative research efforts, advantages of our genetically-improved pine, benefits of top clipping seedlings, importance of dormancy, pales weevil treatments, and details about our genetically- improved seedlings available for sale.

Viewnurseriespublication
Forest Research Review 2006-08
Forest Research Review 2006-08

Research reports and updates from ongoing DOF studies. In this issue: longleaf pine establishment methods, shortleaf pine establishment methods, American chestnut backcross breeding, white pine seedling handling and competition control methods, loblolly pine release tank mixes and surfactants, epicormic branching of white oak, and northern red oak planting.

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Forest Research Review 2007-03
Forest Research Review 2007-03

Research reports and updates from ongoing DOF studies. In this issue: the loblolly pine tree improvement program, competition control for shortleaf pine establishment, competition control for white pine establishment, pruning methods for urban trees, white oak crop tree release, tree-of-heaven control methods, yellow-poplar thinning response, and northern red oak planting.

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Forest Research Review 2007-09
Forest Research Review 2007-09

Research reports and updates from ongoing DOF studies. In this issue: financial value of improved loblolly pine seedlings, loblolly pine planting density, white pine seedling handling and planting study, pre-commercial thinning of loblolly pine, riparian buffer planting success, and tree-of-heaven control methods.

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Forest Research Review 2008-04
Forest Research Review 2008-04

Research reports and updates from ongoing DOF studies. In this issue: row orientation in loblolly pine growth, fertilizer x planting density effects on loblolly pine growth, varietal vs. open-pollinated loblolly pine, North Carolina and South Carolina families of loblolly pine in VA, longleaf pine establishment methods, longleaf pine provenances, biosolids for fertilizing loblolly pine, interplanting loblolly pine, and southern red oak crop tree release and fertilization.

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Forest Research Review 2008-10
Forest Research Review 2008-10

Research reports and updates from ongoing DOF studies. In this issue: loblolly pine seed orchard management strategies, advances in pine plantation silviculture, longleaf pine grafting methods, competition control for shortleaf pine establishment, tip moth control methods for loblolly pine, tree-of-heaven control methods, and northern red oak planting.

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Forest Research Review 2009-04
Forest Research Review 2009-04

Research reports and updates from ongoing DOF studies. In this issue: potential for continued loblolly pine tree improvement, effects of thinning and fertilization in loblolly pine, American chestnut breeding program, longleaf pine provenance study, biosolids for fertilizing loblolly pine, interplanting loblolly pine, tip moth control methods for loblolly pine, and southern red oak crop tree release and fertilization.

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Forest Research Review 2010-03
Forest Research Review 2010-03

Research reports and updates from ongoing DOF studies. In this issue: loblolly pine site index, stem sinuosity in loblolly pine, longleaf pine establishment methods, American chestnut, effects of competing hardwoods on loblolly pine, white pine competition control and storage time, tip moth control methods for loblolly pine, white oak crop tree release and fertilization.

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Forest Research Review 2010-10
Forest Research Review 2010-10

Research reports and updates from ongoing DOF studies. In this issue: Forest Modeling Research Cooperative, potential for pine plantation woody biomass, stem forking in loblolly pine, biosolids for fertilizing loblolly pine, interplanting loblolly pine, loblolly pine growth after age two hardwood control, site preparation vs. release for loblolly pine growth, initial seedling size and establishment methods for northern red oak.

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Forest Research Review 2012-08
Forest Research Review 2012-08

Research reports and updates from ongoing DOF studies. In this issue: effects of pruning in loblolly pine, effects of planting density and fertilizer on loblolly pine growth, varietal vs open-pollinated loblolly pine, biosolids for fertilizing loblolly pine, shortleaf pine provenance test, interplanting loblolly pine, tree shelter comparison for red oak in riparian buffers, crop tree release and fertilization of white oak and southern red oak.

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Forest Research Review 2013-08
Forest Research Review 2013-08

Research reports and updates from ongoing DOF studies. In this issue: fourth cycle loblolly pine tree breeding, spacing impacts on loblolly lumber quality, fertilizer fate and carbon sequestration in loblolly pine, logging slash for skid trail stabilization, longleaf pine provenances, growth and value of low-density loblolly pine plantations, projected value of interplanted loblolly pine, biosolids for fertilizing loblolly pine, growth and value of loblolly pine after site prep vs. release, hardwood plantations in central VA, tree shelters for northern red oak

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Making Sense of the Genetics Market
Making Sense of the Genetics Market

Report explains loblolly pine genetics, tree improvement, and the evolution of seedling markets, and is intended to help landowners understand their choices in seedling genetics. Steve McKeand is Professor of Forestry and Environmental Resources and Director, North Carolina State University Cooperative Tree Improvement Program.

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Making Sense of the Genetics Market
Making Sense of the Genetics MarketViewforest-managementpublication
No. 028 A Shortleaf and Loblolly Pine Flowering Phenology Study; by R. G. Wasser
No. 028 A Shortleaf and Loblolly Pine Flowering Phenology Study; by R. G. WasserOR-028

Report provides results of a 1967 study to compare flowering dates of the different genetic lines of loblolly and shortleaf pines in the DOF seed orchard at that time.

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No. 046 Predicting Number of Sound Seeds per Cone from a Cone Cutting Study in Twelve-Year-Old Loblolly Orchard; by T. A. Dierauf and R. G. Wasser
No. 046 Predicting Number of Sound Seeds per Cone from a Cone Cutting Study in Twelve-Year-Old Loblolly Orchard; by T. A. Dierauf and R. G. WasserOR-046

Report summarizes data and prediction models for estimating seed yields per cone of 20 different coastal plain and piedmont cones in the DOF loblolly pine seed orchard.

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No. 112 A Black Walnut Seed-Source-Elevation Study; by T. A. Dierauf and J. W. Garner
No. 112 A Black Walnut Seed-Source-Elevation Study; by T. A. Dierauf and J. W. GarnerOR-112

Report provides nine-year data from a test comparing 21 different seed sources of black walnut collected within a 100-mile radius but ranging in altitude from 480 to 2,400 feet. Altitude of source did not affect frost resistance but height tended to decrease with increasing source altitude.

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No. 122 Sowing Five Clonal Lots of Loblolly Seed Separately or Randomly Mixed - Results A20 Years; by T. A. Dierauf and J. A. Scrivani
No. 122 Sowing Five Clonal Lots of Loblolly Seed Separately or Randomly Mixed – Results A20 Years; by T. A. Dierauf and J. A. ScrivaniOR-122

Report provides 20-year results of a comparison of seedlings from five open-pollinated loblolly pine parents sown either separately or randomly mixed in the nursery bed. Survival was not affected by sowing pattern, but at age 20, the randomly-mixed seedlings were taller than those sown in pure lots and there were differences among genotypes.

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No. 136 Ten-Year Performance of Eight Longleaf Pine Provenances in Virginia
No. 136 Ten-Year Performance of Eight Longleaf Pine Provenances in VirginiaRR-136

Report provides 10-year results from a study comparing the survival and growth of longleaf pine seedlings from Alabama, Florida, Georgia, Mississippi, North Carolina (two sources), South Carolina, and Virginia. Primarily due to earlier growth initiation and better survival, the Virginia source produced significantly more volume per acre and ranked higher in fitness score than the other provenances.

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No. 141 Performance of Four Hybrid Poplars and Three Native Hardwoods in Plantations in Central Virginia at Age 14
No. 141 Performance of Four Hybrid Poplars and Three Native Hardwoods in Plantations in Central Virginia at Age 14RR-141

Report provides 14-year results of a test to compare plantations of three native hardwood species and four hybrid poplar crosses to loblolly pine for potential fiber production. Of the eight species/hybrids tested, only one hybrid poplar cross – Populus trichocarpa x deltoides – survived and grew well.

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No. 147 Establishment Methods for Longleaf Pine
No. 147 Establishment Methods for Longleaf PineRR-147

Report provides results from a study of the effects of seedling source (NC orchard mix, GA mountain and GA coastal), competition control methods and planting depth on the establishment and early growth of longleaf pine on an old-field site. Five-year results show that the most important factor in  establishment success was scalping. Shallow planting and Oustar at 8 -12 oz./acre were also helpful. 

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The Development of Pine Plantation Silviculture in the Southern United States
The Development of Pine Plantation Silviculture in the Southern United States

Article reviews the contributions of applied silvicultural research in tree improvement, nursery management, site preparation, weed control, and fertilization to plantation forestry in the South. Thomas R. Fox, Eric J. Jokela, and H. Lee Allen.

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