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

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.

1988 ◽  
Vol 18 (5) ◽  
pp. 610-614 ◽  
Author(s):  
Kurt H. Johnsen ◽  
Peter P. Feret ◽  
John R. Seiler

Root growth potential and shoot activity were examined from October until April using northern and southern half-sib families of 1–0 eastern white pine (Pinusstrobus L.) seedlings (grown in a Virginia nursery). There were significant differences in root growth potential between northern and southern provenances and this was apparently due to the larger size of seedlings of southern origin. Heritability estimates indicate that root growth potential is under minimal genetic control in 1–0 eastern white pine seedlings. Southern provenances maintained higher shoot activity at the end of the root growth potential test during the autumn months. By April, northern provenances had surpassed southern provenances in shoot activity. Large differences in shoot activity did not result in large root growth potential differences which may indicate that bud dormancy status does not highly influence root growth potential in 1–0 eastern white pine seedlings.


1985 ◽  
Vol 15 (4) ◽  
pp. 651-656 ◽  
Author(s):  
W. C. Carlson

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.


1989 ◽  
Vol 13 (4) ◽  
pp. 163-169 ◽  
Author(s):  
S. W. Hallgren ◽  
C. G. Tauer

Abstract Root growth potential (RGP), and first-year field survival and growth of shortleaf pine (Pinus echinata Mill.) seedlings were significantly affected by lift date, storage, and family. Seedlings lifted in December and January showed highest RGP, survival, and growth. Storage for 28 daysalways reduced survival and growth, and the effect was greatest for late-lifted seedlings. However, for late planting, the difference in performance between freshly lifted seedlings and earlier lifted and stored seedlings may be small. Large family differences existed for seasonal changesin RGP and survival, suggesting separate management by family may be beneficial. The presence of a terminal bud and secondary needles showed little value in predicting seedling performance, whereas RGP and number of primary lateral roots were strongly correlated with seedling survival. South.J. Appl. For. 13(4):163-169.


1989 ◽  
Vol 5 (3) ◽  
pp. 291-306 ◽  
Author(s):  
K. E. Burr ◽  
R. W. Tinus ◽  
S. J. Wallner ◽  
R. M. King

1988 ◽  
Vol 18 (12) ◽  
pp. 1635-1640 ◽  
Author(s):  
Hans M. Williams ◽  
David B. South ◽  
Glenn R. Glover

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.


1990 ◽  
Vol 63 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J. D. DEANS ◽  
C. LUNDBERG ◽  
M. G. R. CANNELL ◽  
M. B. MURRAY ◽  
L. J. SHEPPARD

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 597
Author(s):  
Jacob A. Reely ◽  
Andrew S. Nelson

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.


New Forests ◽  
1990 ◽  
Vol 4 (3) ◽  
pp. 179-192 ◽  
Author(s):  
David B. South ◽  
Harry S. Larsen ◽  
James N. Boyer ◽  
Hans M. Williams

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