Genetic Variation and the Effect of Herbicide and Fertilization Treatments on Wood Quality Traits in Loblolly Pine

Abstract The effect of silvicultural treatments (herbicide, fertilization, herbicide + fertilization) and the interactions with genetic effects were investigated for wood quality traits in a 16-year-old loblolly pine (Pinus taeda L.) genetic test established in southwest Georgia, USA. Fertilizer and herbicide treatment combinations were applied multiple times to main plots containing twenty-five open-pollinated families as sub plots. Significant differences among treatments were found for all traits. Squared acoustic velocity, used as a surrogate for wood stiffness, was higher in herbicide-only plots compared with other treatments. Wood density was considerably lower in fertilization plots. A large proportion of variance observed for wood quality traits was explained by additive genetic effects, with individual-tree heritabilities ranging from 0.78 (ring 7–16 section wood density) to 0.28 (ring 2–6 section wood density). Corresponding family-mean heritability values were well over 0.86. Genotype-by-treatment interactions were nonsignificant for all traits, indicating no need to match families to silvicultural treatments. Wood quality traits had weak genetic correlations with growth and stem quality traits (stem slenderness, sweep, and branch angle) with a range of −0.33 to 0.43, suggesting that recurrent selection on growth or stem quality traits would not adversely affect wood quality in loblolly pine. Study Implications: Silvicultural treatments of herbicide, fertilization, and their combination had significant effects on wood stiffness and wood density in a 16-year-old loblolly pine genetics-by-silviculture trial. When fertilizer was applied, wood density decreased, but the impact on stiffness was minimal. The herbicide treatment increased wood stiffness. As expected, there were large genetic differences for wood quality traits and growth and stem quality traits. Genetics-by-silvicultural treatment interactions were not significant for wood quality traits; family rankings were quite stable across cultural regimes. Families that performed well under one silvicultural treatment performed well under all treatments.

Download Full-text

Provenance and Family Variation in Biomass Potential of Loblolly Pine in the Piedmont of North Carolina

Forest Science ◽

10.1093/forsci/fxaa056 ◽

2021 ◽

Author(s):

Jessica A Maynor ◽

Fikret Isik ◽

Trevor D Walker ◽

Ross W Whetten ◽

Austin J Heine ◽

...

Keyword(s):

North Carolina ◽

Loblolly Pine ◽

Wood Quality ◽

Biofuel Production ◽

Quality Traits ◽

Stem Form ◽

The Family ◽

Stem Quality ◽

Biomass Potential ◽

Harvest Regimes

Abstract Considerable genetic differences in loblolly pine (Pinus taeda L.) exist for growth, stem form, and wood quality traits that influence biomass/biofuel production. By planting genetically superior trees with desirable biomass/biofuel traits, it is possible to substantially increase the amount of biomass and potential sawtimber trees produced from plantations. Ten of the fastest growing loblolly pine families from two provenances, Atlantic Coastal Plain and Piedmont, were tested for their biomass potential in North Carolina on a Piedmont site. At this northern Piedmont site at age six years, there were no provenance differences for biomass production or for trees with sawtimber potential. Variation in volume and sawtimber potential was significant at the family level. For biomass plantations, risks can be mitigated because of shorter rotation length, allowing for a higher-risk seed lot to capture greater gains in terms of volume. For a longer-rotation sawtimber stand, a more conservative family deployment strategy should be considered to maintain stem quality at the end of the rotation. Understanding the different seed source families and harvest regimes is essential to ensure profitable returns from pine plantations. Study Implications Landowners in the southeastern United States have more choices than ever before regarding the choice of genetic stock of loblolly pine seedlings they plant, and the family selection should reflect the stand management objectives with regard to growth, stem form, and wood quality traits. In a biomass/biofuel production regime, planting families from nonlocal seed sources for increased growth can potentially increase the amount of biomass and sawtimber produced from the plantation, although risks such as increased susceptibility to winter storm damage must be considered. For biomass plantations, with shorter rotation lengths, risks can be reduced allowing for a higher-risk genotype to capture the greater gains in volume. For a sawtimber stand, genotype selections should be more conservative to ensure stem quality at the end of the rotation. Understanding different genotypes and harvest regimes is essential to maximize profit from plantations.

Download Full-text

Genetic effects on wood quality traits of plantation-grown white spruce (Picea glauca) and their relationships with growth

Tree Genetics & Genomes ◽

10.1007/s11295-011-0441-z ◽

2011 ◽

Vol 8 (2) ◽

pp. 303-311 ◽

Cited By ~ 15

Author(s):

Yill-Sung Park ◽

Yuhui Weng ◽

Shawn D. Mansfield

Keyword(s):

Picea Glauca ◽

Wood Quality ◽

White Spruce ◽

Genetic Effects ◽

Quality Traits

Download Full-text

Age trend of heritability, genetic correlation, and efficiency of early selection for wood quality traits in Scots pine

Canadian Journal of Forest Research ◽

10.1139/cjfr-2014-0465 ◽

2015 ◽

Vol 45 (7) ◽

pp. 817-825 ◽

Cited By ~ 13

Author(s):

Zhou Hong ◽

Anders Fries ◽

Harry X. Wu

Keyword(s):

Genetic Correlation ◽

Wood Density ◽

Scots Pine ◽

Wood Quality ◽

Microfibril Angle ◽

Ring Width ◽

Early Selection ◽

Quality Traits ◽

Wood Traits ◽

Selection For

To examine the efficiency of early selection for wood quality traits in the Scots pine (Pinus sylvestris L.) breeding program in Sweden, a total of 778 wood increment cores were sampled from 179 full-sib families in a single progeny trial at 40 years of age. Age trend of inheritance, age–age genetic correlation, and early selection efficiency for eight wood traits including annual ring width, wood density, microfibril angle (MFA), modulus of elasticity (i.e., wood stiffness; MOE), and fibre dimensions were studied. Heritabilities for the eight wood traits reached a plateau between age 5 years and age 15 years, with the highest heritability for radial fibre width and fibre coarseness (∼0.6) and the lowest heritability for ring width (∼0.2). Heritability reached about 0.4 for both wood density and MFA but only reached about 0.3 for MOE. Genetic correlation from early to reference age 30 years reached a very high level (>0.8) for all eight wood traits at age 5 years. Early selection was effective for wood quality traits in Scots pine, and selection at age 8 years is recommended for MOE in Scots pine.

Download Full-text

Genetic Variation in Acoustic Time of Flight and Drill Resistance of Juvenile Wood in a Large Loblolly Pine Breeding Population

Forest Science ◽

10.1093/forsci/fxz002 ◽

2019 ◽

Vol 65 (4) ◽

pp. 469-482 ◽

Cited By ~ 5

Author(s):

Trevor D Walker ◽

Fikret Isik ◽

Steven E McKeand

Keyword(s):

Specific Gravity ◽

Loblolly Pine ◽

Wood Quality ◽

Genetic Correlations ◽

Time Of Flight ◽

Phenotypic Correlation ◽

Environment Interaction ◽

Quality Traits ◽

Economic Traits ◽

Stem Straightness

AbstractAcoustic time of flight and drill resistance (surrogates for wood stiffness and density, respectively) were measured on 11,097 standing trees from 269 pollen-mix families of loblolly pine (Pinus taeda L.) in 6- to 9-year-old progeny tests at eight sites across the southeastern United States. Specific gravity was measured on two test sites. The phenotypic correlation between specific gravity and drill resistance was moderate (r = 0.68), whereas the genetic correlation was very strong (rg = 0.96). Narrow-sense heritabilities for acoustic time of flight and drill resistance were around 0.35 for individual trees and very strong (0.90) for family means. High genetic correlations (>0.80) between pairs of sites suggested a low genotype-by-environment interaction for both traits. Genetic correlations between wood quality traits and other economic traits (growth and stem straightness) were low except for a moderate correlation between acoustic time of flight and tree slenderness (rg = –0.64). The checklot ranked near the middle for both wood quality traits, implying no inadvertent selection occurred in this population that has been selected intensively for volume productivity. This study is the first to apply these tools in a large breeding program, and results suggest they are effective for selecting genotypes for wood quality.

Download Full-text

Effects of Five Silvicultural Treatments on Loblolly Pine in the Georgia Piedmont at Age 20

Southern Journal of Applied Forestry ◽

10.1093/sjaf/28.1.35 ◽

2004 ◽

Vol 28 (1) ◽

pp. 35-40 ◽

Cited By ~ 2

Author(s):

M. Boyd Edwards ◽

Barry D. Shiver ◽

Stephen R. Logan

Keyword(s):

Experimental Study ◽

Loblolly Pine ◽

Basal Area ◽

Intensive Treatment ◽

Pine Plantations ◽

Growth And Yield ◽

Silvicultural Treatments ◽

Herbicide Treatment ◽

Georgia Piedmont ◽

Stand Characteristics

Abstract Age 20 data from a designed experimental study installed on 24 plots at one location in the Lower Piedmont in Jones County, Georgia, were used to evaluate the effect of six silvicultural treatments on survival, growth, and yield of cutover site-prepared loblolly pine plantations in the Georgia Piedmont. The following silvicultural treatments were included in the study: (1) clearcut only, (2) clearcut with all residual trees greater than 1 inch dbh removed by chainsaw, (3) shear and chop, (4) shear, rootrake, burn, and disk, and (5) shear, rootrake, burn, disk, fertilize, and herbicide. Treatment significantly affected all tree and stand characteristics at age 20. The shear, rootrake, burn, disk, fertilize, and herbicide treatment ranked best in all categories with the exception of survival and basal area, which were highest for the shear, rootrake, burn, and disk treatment. The shear and chop treatment was not significantly lower than the most intensive treatment in any measured category. South. J. Appl. For. 28(1):35–40.

Download Full-text

Non-Destructive Assessment of Wood Stiffness in Scots Pine (Pinus sylvestris L.) and its Use in Forest Tree Improvement

Forests ◽

10.3390/f10060491 ◽

2019 ◽

Vol 10 (6) ◽

pp. 491 ◽

Cited By ~ 7

Author(s):

Irena Fundova ◽

Tomas Funda ◽

Harry X. Wu

Keyword(s):

Scots Pine ◽

Growth Traits ◽

Wood Quality ◽

Genetic Correlations ◽

Forest Tree ◽

Wood Stiffness ◽

Standing Trees ◽

Genetic And Phenotypic Correlations ◽

Sib Families ◽

Using Data

Wood stiffness is an important wood mechanical property that predetermines the suitability of sawn timber for construction purposes. Negative genetic correlations between wood stiffness and growth traits have, however, been reported for many conifer species including Scots pine. It is, therefore, important that breeding programs consider wood stiffness and growth traits simultaneously. The study aims to (1) evaluate different approaches of calculating the dynamic modulus of elasticity (MOE, non-destructively assessed stiffness) using data from X-ray analysis (SilviScan) as a benchmark, (2) estimate genetic parameters, and (3) apply index selection. In total, we non-destructively measured 622 standing trees from 175 full-sib families for acoustic velocity (VEL) using Hitman and for wood density (DEN) using Resistograph and Pilodyn. We combined VEL with different wood densities, raw (DENRES) and adjusted (DENRES.TB) Resistograph density, Pilodyn density measured with (DENPIL) and without bark (DENPIL.B), constant of 1000 kg·m−3 (DENCONST), and SilviScan density (DENSILV), to calculate MOEs and compare them with the benchmark SilviScan MOE (MOESILV). We also derived Smith–Hazel indices for simultaneous improvement of stem diameter (DBH) and wood stiffness. The highest additive genetic and phenotypic correlations of the benchmark MOESILV with the alternative MOE measures (tested) were attained by MOEDENSILV (0.95 and 0.75, respectively) and were closely followed by MOEDENRES.TB (0.91 and 0.70, respectively) and MOEDENCONST and VEL (0.91 and 0.65, respectively for both). Correlations with MOEDENPIL, MOEDENPIL.B, and MOEDENRES were lower. Narrow-sense heritabilities were moderate, ranging from 0.39 (MOESILV) to 0.46 (MOEDENSILV). All indices revealed an opportunity for joint improvement of DBH and MOE. Conclusions: MOEDENRES.TB appears to be the most efficient approach for indirect selection for wood stiffness in Scots pine, although VEL alone and MOEDENCONST have provided very good results too. An index combining DBH and MOEDENRES.TB seems to offer the best compromise for simultaneous improvement of growth, fiber, and wood quality traits.

Download Full-text

Genotypic Stability Effects on Predicted Family Responses to Silvicultural Treatments in Loblolly Pine

Southern Journal of Applied Forestry ◽

10.1093/sjaf/21.2.84 ◽

1997 ◽

Vol 21 (2) ◽

pp. 84-89 ◽

Cited By ~ 12

Author(s):

Steven E. McKeand ◽

Robert P. Crook ◽

H. Lee Allen

Keyword(s):

Pinus Taeda ◽

Loblolly Pine ◽

Growth Responses ◽

Intensive Culture ◽

Genotype By Environment ◽

Silvicultural Treatments ◽

Genotypic Stability ◽

Superior Genotypes ◽

Using Data ◽

Pinus Taeda L

Abstract The lack of rank change in growth characteristics when open-pollinated families of loblolly pine (Pinus taeda L.) are planted on different sites in the Southeast has greatly simplified breeding for superior genotypes. Although family rank does not usually change, genotype by environment interactions (GxE) may be very important in operational deployment of families in regeneration programs. Using data from GxE trials and two site preparation-fertilization-herbicide trials, we estimated the growth that different families should achieve following application of these silvicultural practices. Better performing families tend to be most responsive to site changes (i.e. genetically unstable). Growth responses to silvicultural treatment will be overestimated if only the most responsive families are used in silvicultural research trials. Similarly, genetic gains will be overestimated if gain trials are planted on only the best sites or receive intensive culture. South. J. Appl. For. 21(2):84-89.

Download Full-text