Changes in mitotic index during onset of dormancy in Douglas-fir seedlings

1980 ◽  
Vol 10 (3) ◽  
pp. 371-378 ◽  
Author(s):  
W. C. Carlson ◽  
W. D. Binder ◽  
C. O. Feenan ◽  
C. L. Preisig
Keyword(s):  
Mitotic Index ◽  
Cold Storage ◽  
Rapid Determination ◽  
Moisture Stress ◽  
Height Growth ◽  
Douglas Fir ◽  
Seed Source ◽  
Reduced Height ◽  
Terminal Buds

A method is presented for rapid determination of the mitotic index in terminal buds of Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco. Fertilization at planting increased mitotic index but fertilized seedlings entered dormancy at the same time as unfertilized seedlings. Cold storage, prior to dormancy, reduced mitotic index rapidly and was related to reduced height growth the following year. The effects of moderate moisture stress and seed source on mitotic index were slight.

scholarly journals Soil disturbance and 10-year growth response of coast Douglas-fir on nontilled and tilled skid trails in the Oregon Cascades

2002 ◽  
Vol 32 (2) ◽  
pp. 233-246 ◽  
Author(s):  
Ronald Heninger ◽  
William Scott ◽  
Alex Dobkowski ◽  
Richard Miller ◽  
Harry Anderson ◽  
...  
Keyword(s):  
Tree Growth ◽  
Volume Growth ◽  
Soil Surface ◽  
Soil Bulk Density ◽  
Soil Disturbance ◽  
Height Growth ◽  
Douglas Fir ◽  
Negative Effects ◽  
Fine Soil ◽  
Reduced Height

We (i) quantified effects of skidder yarding on soil properties and seedling growth in a portion of western Oregon, (ii) determined if tilling skid trails improved tree growth, and (iii) compared results with those from an earlier investigation in coastal Washington. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were hand planted at eight recent clearcuts in skid ruts in either nontilled or tilled trails, in adjacent soil berms, and in adjacent logged-only portions. Four and 5 years after skidding, rut depths averaged 15 cm below the original soil surface; mean fine-soil bulk density (0–30 cm depth) below ruts of nontilled trails exceeded that on logged-only portions by 14%. Height growth on nontilled trails averaged 24% less than on logged-only portions in year 4 after planting and decreased to 6% less in year 7. For years 8–10, mean height growth was similar for all treatments. Reduced height growth lasted for about 7 years compared with 2 years for coastal Washington. Ten years after planting, trees in skid-trail ruts averaged 10% shorter with 29% less volume than those on logged-only portions. Tillage improved height and volume growth to equal that on logged-only portions. Generalizations about negative effects of skid trails on tree growth have limited geographic scope.

Controlled Moisture Stress to Improve Cold Hardiness and Morphology of Douglas-fir Seedlings

1979 ◽  
Vol 25 (4) ◽  
pp. 576-582
Author(s):  
John Blake ◽  
Joe Zaerr ◽  
Stephen Hee
Keyword(s):  
Nitrogen Content ◽  
Pseudotsuga Menziesii ◽  
Cold Storage ◽  
Cold Hardiness ◽  
Moisture Stress ◽  
Douglas Fir ◽  
Root Weight ◽  
Mild Stress ◽  
Stress Treatment

Abstract Nursery-grown seedlings of Douglas-fir (Pseudotsuga menziesii) were subjected to three levels of moisture stress between late July and the end of August. Measurements in October and December showed that mild stress of -5 to -10 bars significantly improved cold hardiness. In a second experiment, the effectiveness of the mild stress treatment decreased as the onset of the stress was delayed from mid-July until September 1. Furthermore, the earlier onset of stress decreased the height and shoot/root ratio, but increased the root weight and nitrogen content of the needles. For seedlings lifted in October, mild stress also decreased mortality from cold storage. Forest Sci. 25:576-582.

scholarly journals Effect of Leader Clipping on Height Growth of Young Coastal Douglas-Fir (Pseudotsuga menziesii var. menziesii)

2002 ◽  
Vol 17 (2) ◽  
pp. 75-77 ◽  
Author(s):  
Frank C. Sorensen
Keyword(s):  
Pseudotsuga Menziesii ◽  
Height Growth ◽  
Douglas Fir ◽  
Height Increment ◽  
Depressing Effect ◽  
Linear Fashion ◽  
Diameter Increment ◽  
Reduced Height

Abstract Leaders of 3- through 7-yr-old Douglas-fir seedlings were left unclipped or were clipped for 1 to 4 consecutive years. Terminal removal reduced height increment in a significantly linear fashion and was about 19 cm for each year clipped. All treatments had comparable height increment in the 4 yr after clipping, and the initial depressing effect on height was still present at age 23. Diameter increment was reduced but not significantly. West. J. Appl. For. 17(2):75–77

Sitka Spruce and Douglas fir Seedlings in the Nursery and in Cold Storage: Root Growth Potential, Carbohydrate Content, Dormancy, Frost Hardiness and Mitotic Index

1990 ◽  
Vol 63 (1) ◽  
pp. 9-27 ◽  
Author(s):  
M. G. R. CANNELL ◽  
P. M. TABBUSH ◽  
J. D. DEANS ◽  
M. K. HOLLINGSWORTH ◽  
L. J. SHEPPARD ◽  
...  
Keyword(s):  
Root Growth ◽  
Mitotic Index ◽  
Cold Storage ◽  
Sitka Spruce ◽  
Douglas Fir ◽  
Carbohydrate Content ◽  
Growth Potential ◽  
Frost Hardiness ◽  
Storage Root ◽  
Root Growth Potential

Effects of Cold Storage and Planting Date on Red Pine Survival and Growth

1985 ◽  
Vol 2 (2) ◽  
pp. 51-53 ◽  
Author(s):  
Dallas J. Emch ◽  
Kenneth L. Carvell
Keyword(s):  
Cold Storage ◽  
Height Growth ◽  
Planting Date ◽  
Red Pine ◽  
Good Survival ◽  
Planting Dates ◽  
Reduced Height ◽  
Significant Difference ◽  
Before And After ◽  
One Year

Abstract Effects of cold storage and planting date on first-year survival and height growth of red pine seedlings were evaluated in a one-year study in north-central West Virginia. Both survival and height growth were reduced as time in cold storage increased. Good survival was obtained for plantings made as late as 25 June, after 73 days in cold storage. Satisfactory height growth occurred for plantings made as late as 23 July. There was no significant difference in survival before and after fall frost for any planting dates except the 20 August planting. Reduced height growth for the later plantings was probably a consequence of the short growing season remaining. There was no indication that the length of time in cold storage affected the period required for buds to break dormancy. North J. Appl. For. 2:51-53, June 1985.

Paclobutrazol and triadimefon effects on conifer seedling growth and water relations

1990 ◽  
Vol 20 (6) ◽  
pp. 722-729 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Stomatal Conductance ◽  
Active Ingredient ◽  
White Spruce ◽  
Height Growth ◽  
Douglas Fir ◽  
Sand Culture ◽  
Growth Responses ◽  
Synthesis Inhibitor ◽  
Xylem Water Potential ◽  
Reduced Height

Growth responses of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings to the gibberellin synthesis inhibitor paclobutrazol were examined in sand culture. Shoot and root dry weights and root lengths were reduced at 5 mg (active ingredient) of paclobutrazol per litre, in the nutrient solution, although the proportion of dry matter allocated to roots was increased by 5 mg (active ingredient) of paclobutrazol per litre. Similar effects were observed with triadimefon, although the reduction in height growth was less in triadimefon-treated seedlings than in paclobutrazol-treated seedlings. Stomatal conductance, transpiration, and needle area:weight ratio were reduced by both paclobutrazol and triadimefon treatments of 13.5-week-old seedlings, although paclobutrazol was more effective than triadimefon in reducing needle arear:weight ratio. Treatment of 1-year-old container seedlings of Douglas-fir and white spruce (Piceaglauca (Moench) Voss) by shoot dipping or plug drenching with paclobutrazol, in December or March, reduced height growth and new needle area:weight ratio after 6 weeks growth in a greenhouse. Xylem water potential of paclobutrazol-drenched seedlings was increased by 0.7 MPa above controls (−1.8 MPa) 11 weeks after planting, and stomatal conductance of drenched white spruce increased with paclobutrazol concentration.

Weak Beam Imaging and Diffraction Studies of Stacking Faults in Silicon

1976 ◽  
Vol 34 ◽  
pp. 590-591
Author(s):  
T. Y. Tan ◽  
W. K. Tice
Keyword(s):  
Fast Neutron ◽  
Rapid Determination ◽  
Stacking Faults ◽  
Imaging Method ◽  
Large Reduction ◽  
Dislocation Loops ◽  
Fringe Spacing ◽  
Weak Beam ◽  
Kinematical Theory

In studying ion implanted semiconductors and fast neutron irradiated metals, the need for characterizing small dislocation loops having diameters of a few hundred angstrom units usually arises. The weak beam imaging method is a powerful technique for analyzing these loops. Because of the large reduction in stacking fault (SF) fringe spacing at large sg, this method allows for a rapid determination of whether the loop is faulted, and, hence, whether it is a perfect or a Frank partial loop. This method was first used by Bicknell to image small faulted loops in boron implanted silicon. He explained the fringe spacing by kinematical theory, i.e., ≃l/(Sg) in the fault fringe in depth oscillation. The fault image contrast formation mechanism is, however, really more complicated.

Methods for rapid determination of pecan (Carya illinoensis) seed viability

2017 ◽  
Vol 45 (2) ◽  
pp. 455-464
Author(s):  
T.T. Xue ◽  
J. Liu ◽  
Y.B. Shen ◽  
G.Q. Liu
Keyword(s):  
Rapid Determination ◽  
Seed Viability ◽  
Carya Illinoensis
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