Seed spacing and seedling biomass: Effect on root growth potential of loblolly pine (Pinus taeda)

New Forests ◽  
1990 ◽  
Vol 4 (3) ◽  
pp. 179-192 ◽  
Author(s):  
David B. South ◽  
Harry S. Larsen ◽  
James N. Boyer ◽  
Hans M. Williams
Keyword(s):  
Root Growth ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Growth Potential ◽  
Root Growth Potential ◽  
Seedling Biomass ◽  
Seed Spacing

Root Stripping Reduces Root Growth Potential Of Loblolly Pine Seedlings

1990 ◽  
Vol 14 (4) ◽  
pp. 196-199 ◽  
Author(s):  
David B. South ◽  
Nancy J. Stumpff
Keyword(s):  
Root Growth ◽  
Loblolly Pine ◽  
Relative Effect ◽  
Growth Potential ◽  
Root Weight ◽  
Root Growth Potential ◽  
Root Shoot Ratio ◽  
Pine Seedlings ◽  
Pinus Taeda L ◽  
Root Apices

Abstract Stripping short roots from individual loblolly pine (Pinus taeda L.) seedlings was accomplished by pulling the root system through a closed fist either 1, 2, or 4 times. The root growth potential (RGP) of the seedlings was directly related to the intensity of stripping. One stripping removed approximately 2% of the total root weight, yet reduced the number of root apices by 22% and caused a 47% reduction in RGP. Four strippings removed approximately 11% of the root weight, reduced the root/shoot ratio by about 9% and resulted in a 69% reduction in RGP. Although stripping of roots reduced both shoot and root growth, the relative effect on new shoot growth was not as great as with new root growth. Root stripping effectively eliminated any correlation between seedling diameter and RGP. South. J. Appl. For. 14(4):196-199.

Changes in loblolly pine root growth potential from September to April

1987 ◽  
Vol 17 (7) ◽  
pp. 635-643 ◽  
Author(s):  
Laura E. DeWald ◽  
Peter P. Feret
Keyword(s):  
Root Growth ◽  
Loblolly Pine ◽  
Environmental Changes ◽  
Lateral Roots ◽  
Root Systems ◽  
Shoot Elongation ◽  
Growth Potential ◽  
Late Winter ◽  
Root Growth Potential ◽  
Shoot Phenology

Loblolly pine (Pinustaeda L.) 1 + 0 seedlings were periodically hand lifted from a Virginia nursery to determine how root growth potential (RGP) varied between September and April. Several seedling characteristics, RGP, and shoot phenology were recorded for each lift date in 1983–1984 and 1984–1985. An attempt was made to relate RGP variation to changes in the nursery environment and to shoot phenology. Root growth potential variation was consistent between years and was more closely related to shoot phenological changes than to short-term environmental changes. During the development of dormancy, RGP was low, RGP increased when shoot activity resumed during the RGP tests (late winter, early spring), and declined as active shoot elongation began in the nursery. When RGP was low, elongation of existing lateral roots primarily contributed to the new root systems, but as seedling metabolism increased in the late winter, new root initiation also contributed to new root systems. Absolute differences in RGP between years may be related to the fibrosity of seedling root systems.

Effect of Undercutting on Loblolly Pine Seedling Size and Its Relation to Root Growth Potential

1986 ◽  
Vol 10 (1) ◽  
pp. 24-27 ◽  
Author(s):  
Peter P. Feret ◽  
Richard E. Kreh
Keyword(s):  
Root Growth ◽  
Loblolly Pine ◽  
Weight Ratio ◽  
Growth Potential ◽  
Shoot Biomass ◽  
Root Weight ◽  
Root Growth Potential ◽  
Seedling Size ◽  
Seedling Physiology ◽  
Shoot Weight

Abstract Loblolly pine seedlings undercut using five different treatments extending from July to September exhibited significant alteration of shoot and root biomass. Root growth potential (RGP) (measured by number of new elongating roots) was not significantly altered by undercutting. Undercutting did significantly alter the RGP/root weight ratio and the RGP/shoot weight ratio because of both concomitant changes in root and shoot biomass and changes in seedling physiology. Root growth potential and efficiency of existing old roots to produce new roots were not well correlated with seedling size.

Effects of Air Drying on Survival, Height, and Root Growth Potential of Loblolly Pine Seedlings

1985 ◽  
Vol 9 (2) ◽  
pp. 125-128 ◽  
Author(s):  
Peter P. Feret ◽  
Richard E. Kreh ◽  
Carolyn Mulligan
Keyword(s):  
Root Growth ◽  
Loblolly Pine ◽  
Seedling Survival ◽  
Field Performance ◽  
Strong Relationship ◽  
Growth Potential ◽  
First Year ◽  
Ambient Conditions ◽  
Root Growth Potential ◽  
Air Drying

Abstract Loblolly pine (Pinus taeda) seedlings were dried by exposure to ambient conditions and their subsequent quality evaluated for both field performance and root-growth potential. Seedling survival after one growing season was diminished 6.9% and first-year height growth 17% for each 10 minutes of exposure out-doors. Root-growth potential was significantly diminished by air drying with the half-life of a seedling ranging from 15 to 35 minutes depending on ambient conditions. A strong relationship between field performance and root-growth potential was shown. Results support earlier research concluding that seedling desiccation must be avoided if seedling quality is to be maintained at the planting site.1

Root System Considerations in the Quality of Loblolly Pine Seedlings

1986 ◽  
Vol 10 (2) ◽  
pp. 87-92 ◽  
Author(s):  
W. C. Carlson
Keyword(s):  
Root Growth ◽  
Soil Temperature ◽  
Root System ◽  
Water Uptake ◽  
Loblolly Pine ◽  
Growth Potential ◽  
System Quality ◽  
Root Growth Potential ◽  
Root Volume

Abstract A series of studies was carried out to determine quantitative relationships between root system quality parameters and ability to take up water, and expand the root system into adjacent soil. Root system size, described by displacement of water (i.e., root volume), determines the potential for water uptake prior to new root growth. Seedlings of comparatively high root volume also have superior root growth potential (RGP). After new root growth, the potential for water uptake is proportional to the number of new roots produced. The beginning of rapid root growth after planting is dependent on soil temperature. Root growth potential rank of open-pollinated families can change with soil temperature, which also alters RGP within family. Nursery practices that favor production of seedlings with high root volume and high RGP will increase the quality of seedlings of a given height. South. J. Appl. For. 10:87-92, May 1986.

Effects of natural chilling and cold storage on budbreak and root growth potential of loblolly pine (Pinustaeda L.)

1985 ◽  
Vol 15 (4) ◽  
pp. 651-656 ◽  
Author(s):  
W. C. Carlson
Keyword(s):  
Root Growth ◽  
Loblolly Pine ◽  
Cold Storage ◽  
Growth Potential ◽  
Bud Dormancy ◽  
Root Growth Potential ◽  
One Year ◽  
Chilling Hours

One-year-old loblolly pine (Pinustaeda L.) seedlings of 20 open-pollinated families were lifted from the nursery on November 23, 1981, and January 18, 1982, after the accumulation of 207 and 734 chilling hours (0 °C ≤ temperature ≤ 8 °C), respectively. Seedlings were tested for bud dormancy (rest) intensity and root growth potential after lifting and after 500 h in cold storage. There was a twofold range in dormancy intensity of 20 families at 207 chilling hours. Bud dormancy intensity was reduced as rapidly in cold storage as in nature. At 1234 chilling hours (500 h of which were in storage), families did not significantly differ in dormancy intensity. Root growth potential was severely reduced by storage (500 h at 2–4 °C) of seedlings lifted on November 23. In contrast, root growth potential of similarly stored seedlings lifted January 18 either was unaltered or had improved in storage.

Effect of bud status and seedling biomass on root growth potential of loblolly pine

1988 ◽  
Vol 18 (12) ◽  
pp. 1635-1640 ◽  
Author(s):  
Hans M. Williams ◽  
David B. South ◽  
Glenn R. Glover
Keyword(s):  
Root Growth ◽  
Loblolly Pine ◽  
Dry Weight ◽  
Shoot Tip ◽  
Growth Potential ◽  
Root Growth Potential ◽  
Seedling Size ◽  
Covariate Analysis ◽  
Terminal Bud ◽  
Terminal Buds

Container-grown seedlings of Pinustaeda L. with well-formed terminal buds, feather-tops (a succulent shoot tip crowned with a tuft of primary needles), and terminal buds removed (debudded) were sampled in November, December, and January. Root growth potential for unstored and stored seedlings was measured to determine if it is affected by shoot tip morphology. Seedlings with buds or debudded seedlings had higher root growth potential than feather-top seedlings. Root growth potential was correlated with several morphological variables, including total ovendry weight (r = 0.81). As feather-top seedlings were smaller in diameter and biomass, a covariate analysis (using seedling dry weight as a covariate) was conducted. The covariate analysis indicated that differences in root growth potential between shoot types could be accounted for by differences in seedling size. The percentage of seedlings resuming growth and the total amount of new shoot growth during the test of root growth potential showed that feather-top seedlings and seedlings with terminal buds respond similarly to chilling temperatures. These results indicate that seedling size is more important than the presence of a well-formed terminal bud when seedlings are graded before outplanting.

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