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.

Root growth potential and bud dormancy of 2 + 0 eastern white pine grown in a Virginia nursery

1989 ◽  
Vol 19 (12) ◽  
pp. 1598-1602
Author(s):  
Kurt H. Johnsen ◽  
Peter P. Feret ◽  
John R. Seiler
Keyword(s):  
Root Growth ◽  
Growth Potential ◽  
Bud Dormancy ◽  
Dormancy Release ◽  
White Pine ◽  
Eastern White Pine ◽  
Root Growth Potential ◽  
Terminal Bud ◽  
Chilling Hours ◽  
The Relationship

Root growth potential and dormancy release index were examined over 2 years using 2 + 0 eastern white pine seedlings grown in a Virginia nursery. Root growth potential patterns were quite different between years. The relationship between dormancy release index and chilling sums (0–7 °C) was consistent between years. Approximately 2800 chilling hours were necessary to break terminal bud dormancy fully. There was a highly significant, positive linear relationship between root growth potential and dormancy release index above a dormancy release index of 0.20 when 2 years data were combined. For dormancy release index values <0.20, the relationship between root growth potential and dormancy release index was inconsistent between years.

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

Carbohydrate reserves and root growth potential in Douglas-fir seedlings before and after cold storage

1982 ◽  
Vol 12 (4) ◽  
pp. 905-912 ◽  
Author(s):  
Gary A. Ritchie
Keyword(s):  
Root Growth ◽  
Cold Storage ◽  
Drought Resistance ◽  
Dry Weight ◽  
Douglas Fir ◽  
Growth Potential ◽  
Frost Hardiness ◽  
Root Growth Potential ◽  
Carbohydrate Reserves ◽  
Before And After

Carbohydrate reserves and root growth potential (RGP) of 2 + 0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were monitored through a lifting season and during dark, cold storage. Concentrations of total nonstructural carbohydrate and extractable sugars in root and stem tissues remained relatively constant through winter, while foliar sugars showed a sharp midwinter peak at about 195 mg•g−1 dry weight. RGP was lowest in November and March and peaked in January. During storage at +2 and −1 °C, carbohydrates were depleted in all tissues through respiratory consumption. In contrast, RGP increased during the first 6 months in storage and then fell rapidly. The results do not support the view that changes in RGP are driven by changes in carbohydrate concentrations. Storage may affect frost hardiness and drought resistance through its effect on sugar concentrations.

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.

Physiological indicators of tolerance to cold storage in Sitka spruce and Douglas-fir seedlings

1991 ◽  
Vol 21 (6) ◽  
pp. 890-901 ◽  
Author(s):  
H. M. McKay ◽  
W. L. Mason
Keyword(s):  
Root Growth ◽  
Cold Storage ◽  
Electrolyte Leakage ◽  
Fine Roots ◽  
Cold Hardiness ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Growth Potential ◽  
Root Growth Potential ◽  
Plant Vigour

Two-year-old transplants and undercuts of Piceasitchensis (Bong.) Carr. and Pseudotsugamenziesii (Mirb.) Franco were cold-stored (1 °C) for 1 to 7 months ending in April 1989. Their physiological arid morphological condition at lifting and after storage was assessed and related to survival and height increment on a reafforestation site after one growing season. Physiological assessments made between October and April at lifting were root growth potential, tolerance of fine roots to chronic cold, shoot and root mitotic index, root elongation, and electrolyte leakage from the shoot and roots. Shoot cold hardiness was assessed between October and mid-December. The seasonal changes in these parameters and the effect of species and undercutting treatments are described. At lifting, root growth potential identified (i) differences due to species and undercutting treatments and (ii) the earliest possible safe lifting dates of P. menziesii but not of P. sitchensis. After cold storage, plant vigour was assessed by root growth potential and shoot and root membrane integrity. Membrane integrity of the fine roots was a very good indicator of survival. There was a highly significant, negative correlation between the rate of electrolyte leakage, indicating membrane damage, and survival (p ≤ 0.001, r = −0.90).

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.

Relationships among cold hardiness, root growth potential and bud dormancy in three conifers

1989 ◽  
Vol 5 (3) ◽  
pp. 291-306 ◽  
Author(s):  
K. E. Burr ◽  
R. W. Tinus ◽  
S. J. Wallner ◽  
R. M. King
Keyword(s):  
Root Growth ◽  
Cold Hardiness ◽  
Growth Potential ◽  
Bud Dormancy ◽  
Root Growth Potential
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