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

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).

Influence of nursery culture on growth, cold hardiness, and drought resistance of yellow cypress

1993 ◽  
Vol 23 (12) ◽  
pp. 2537-2547 ◽  
Author(s):  
J.T. Arnott ◽  
S.C. Grossnickle ◽  
P. Puttonen ◽  
A.K. Mitchell ◽  
R.S. Folk
Keyword(s):  
Root Growth ◽  
Drought Resistance ◽  
Cold Hardiness ◽  
Shoot Growth ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Moisture Stress ◽  
Growth Potential ◽  
Root Growth Potential ◽  
Short Day

The influence of short-day (9 h) and long-day photoperiods (18 h), and three levels of plant moisture stress (none and dried to predawn shoot water potentials of −1.0 or −1.8 MPa), applied for 7 weeks beginning in mid-July 1990, were studied on greenhouse-grown stecklings (rooted cuttings) of yellow cypress (Chamaecyparisnootkatensis (D. Don) Spach). A series of morphological and physiological measurements were made on the stecklings during and after the treatment period. Moisture stress significantly reduced steckling shoot growth and shoot dry weight by lowering net photosynthesis rates, while short-day photoperiods did not. The most pronounced growth reductions occurred when the treatments were combined, but effects were short-lived, with shoot growth resuming soon after the treatments ended. The short-day and moisture-stress treatment had no significant effect on root dry weight, shoot/root ratio, or water balance ratio. The risk of using moisture stress to control shoot growth in the nursery was low; mortality did not occur until the stecklings had been without water for at least 9 days. Moisture-stress treatments increased steckling root growth potential but had little effect on osmotic adjustment, cell elasticity, dry weight or symplastic fractions, cuticular transpiration, resistance to plant water movement, and relative water content of the shoots; short-day treatments had no influence on any of these parameters. Short days and moisture stress, singly or combined, had little effect on steckling cold hardiness. Steckling gas exchange rates were reduced significantly by low root temperature. In a 6-week controlled-environment simulation of planting-site moisture conditions, no significant differences in steckling net photosynthesis, transpiration, or stomatal conductance were found among nursery treatments; those that had been subjected to moisture stress in the nursery had small growth increases after planting in both wet and dry soil moisture regimes. We conclude that shoot growth of yellow cypress stecklings was controlled in the nursery using 9-h photoperiods and −1.8 MPa predawn shoot water potentials. Improved cold hardiness of the stecklings was not achieved using these nursery cultural methods, but moisture stress did confer some measure of drought resistance immediately after treatment, with higher root growth potential and lower shoot mass.

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.

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 System Fibrosity of Sitka Spruce Transplants: Relationship with Root Growth Potential

1990 ◽  
Vol 63 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J. D. DEANS ◽  
C. LUNDBERG ◽  
M. G. R. CANNELL ◽  
M. B. MURRAY ◽  
L. J. SHEPPARD
Keyword(s):  
Root Growth ◽  
Root System ◽  
Sitka Spruce ◽  
Growth Potential ◽  
Root Growth Potential

scholarly journals Root Growth Potential and Microsite Effects on Conifer Seedling Establishment in Northern Idaho

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 597
Author(s):  
Jacob A. Reely ◽  
Andrew S. Nelson
Keyword(s):  
Root Growth ◽  
Douglas Fir ◽  
Seedling Quality ◽  
Growth Potential ◽  
Larix Occidentalis ◽  
Root Growth Potential ◽  
Western Larch ◽  
Neighborhood Conditions ◽  
Seedling Performance ◽  
Survival And Growth

Environmental conditions and seedling quality interact to produce complex patterns of seedling survival and growth. Root growth potential (RGP) is one metric of seedling quality that can be rapidly measured prior to planting, but the correlation of RGP and seedling performance is not consistent across studies. Site factors including microsite objects that cast shade and competing vegetation can also influence seedling performance. We examined the effects of RGP, presence/absence of a microsite object, and competition cover on the survival and growth of three native conifers to the Inland Northwest, USA, over 5 years. We found that RGP had no effect on the survival or growth of western larch (Larix occidentalis), Douglas fir (Pseudotsuga menziesii var. glauca), and grand fir (Abies grandis) at a mesic north aspect site and a xeric south aspect site. Comparatively, the presence of a microsite increased the odds of survival by 37% for western larch and 158% for grand fir, while the absence of forb cover increased the odds of survival of western larch by 72% and of grand fir by 26%. Douglas fir was less sensitive to microsites and competition. The strong effects of neighborhood conditions around seedlings help inform silvicultural practices to enhance the establishment of western larch and grand fir, including planting seedlings near shading objects and competition control, while these practices may not be as important for Douglas fir.

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
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