Carbon and nitrogen allocation patterns of Douglas-fir seedlings fertilized with nitrogen in autumn. II. Field performance

1986 ◽  
Vol 16 (5) ◽  
pp. 903-909 ◽  
Author(s):  
H. A. Margolis ◽  
R. H. Waring
Keyword(s):  
Free Amino ◽  
Shoot Growth ◽  
Field Performance ◽  
Growing Season ◽  
Frost Damage ◽  
Douglas Fir ◽  
Summer Drought ◽  
Tree Roots ◽  
Relative Growth ◽  
Relative Growth Rates

October-fertilized and unfertilized 2-0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were outplanted the following February. Half of each planting block was seeded with grass to induce water stress during the typical summer drought. Sucrose was applied to soil around each seedling to limit availability of nitrogen to tree roots. Fertilized seedlings broke bud 9–10 days earlier, produced more shoot growth, and, as shown in later harvests, had higher relative growth rates than unfertilized seedlings. However, initial differences in growth response were due primarily to the earlier budbreak. Seedlings growing with grass had predawn water potentials of −1.5 MPa by early August; by September 3, unfertilized seedlings growing with grass were significantly more stressed than any others. Although free amino acid and total nitrogen concentrations were higher in fertilized than unfertilized seedlings when planted, they became equal by the end of one growing season. However, fertilized seedlings contained more free amino acids and nitrogen because of their greater size. Grass competition affected both seedling nitrogen and carbohydrate chemistry. After one growing season, fertilized seedlings had greater height increment, shoot growth, leaf area, relative growth rate, and production per unit nitrogen. Although autumn fertilization benefited these Douglas-fir seedlings, negative effects could result from carbohydrate depletion because of increased respiration or from frost damage because of earlier budbreak.

scholarly journals Plant Growth Regulator Effects on Germination and Root Traits of ‘Lambada’ and ‘Don Victor’ Onion Cultivars

HortScience ◽  
2017 ◽  
Vol 52 (12) ◽  
pp. 1759-1764
Author(s):  
Maria A. Macias-Leon ◽  
Daniel I. Leskovar
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Synergistic Effects ◽  
Field Performance ◽  
Root Traits ◽  
Root Surface ◽  
Root Diameter ◽  
Root Surface Area ◽  
Relative Growth ◽  
Relative Growth Rates

Onions (Allium cepa L.) are easily outcompeted by weeds because of slow germination and relative growth rates. Therefore, high percentage of seed germination and root vigor are important traits to improve field performance. The effects of exogenous plant growth regulators (PGRs), 2-chloroethylphosphonic acid (ethephon, Eth), indole-3-acetic acid (IAA), trans-zeatin (tZ), and 1-aminocyclopropane-1-carboxylic acid (ACC) were evaluated on the germination and root growth of ‘Don Victor’ (yellow) and ‘Lambada’ (red) onion seedlings. Seeds were soaked for 10 hours in hormonal solutions and water (hydro-priming). Seed germination improved with Eth (30 and 100 μm), Eth (100 μm) + IAA (10 μm), and IAA (3 μm) treatments. Root surface area (RSA) increased in response to Eth at 30 and 100 μm, Eth + IAA, and 3 μm IAA. Root length (RL) and root diameter (RD) were enhanced by 1 μm tZ and 100 μm ACC. Eth reduced RL and RD, whereas IAA showed no effects. A subsequent experiment evaluated synergistic effects of different PGRs. Treatment of seeds with ACC (250 μm) + tZ (0.5 μm) and ACC (250 μm) + tZ (0.5 μm) + Eth (20 μm) enhanced RL and RD. RSA was unaffected by ACC + tZ + Eth. The results suggest that exogenous PGRs could be useful to enhance germination, RL, and RSA of onion seedlings.

Early Development of Three Douglas-Fir Stocktypes on a Droughty Skeletal Soil

1989 ◽  
Vol 4 (1) ◽  
pp. 21-24 ◽  
Author(s):  
Stephen D. Hobbs ◽  
Michael S. Crawford ◽  
Beverly A. Yelczyn
Keyword(s):  
Surface Soil ◽  
Morphological Characteristics ◽  
Field Performance ◽  
Douglas Fir ◽  
Root Characteristics ◽  
Relative Growth ◽  
Seedling Root ◽  
Absolute Growth ◽  
Southwest Oregon ◽  
Better Than

Abstract Three stocktypes of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) were planted in a droughty, skeletal soil in southwest Oregon. After 5 years, container-grown plugs and plug-1 transplants survived significantly better than 2-0 bareroots. Seedling root systems were largely confined to the surface soil, with relatively little development upslope or deeper than 15 cm. Stocktype morphology differed significantly at planting. However, annual absolute growth, annual relative growth, and shoot and root characteristics did not differ significantly after 5 years. These results suggest that, on similar sites, seedling morphological characteristics within the range of those measured in this study may not affect growth and that stocktype designation along may not be adequate for predicting field performance. West. J. Appl. For. 4(1):21-24, January 1989.

Competition affects shoot morphology, growth duration, and relative growth rates of Douglas-fir saplings

1991 ◽  
Vol 21 (4) ◽  
pp. 474-481 ◽  
Author(s):  
Timothy B. Harrington ◽  
John C. Tappeiner II
Keyword(s):  
Basal Area ◽  
Douglas Fir ◽  
Morphological Parameters ◽  
Growth Duration ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Growing Seasons ◽  
Forest Sites ◽  
Bud Size ◽  
Rates Of Growth

Saplings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) were grown with and without competition from tanoak (Lithocarpusdensiflorus (Hook. & Arn.) Rehd.) at two forest sites in southwestern Oregon. Competition reduced the following morphological parameters on Douglas-fir shoots: number and size of buds; lengths of shoots, internodes, and needles; number of internodes; and biomass of foliage and wood. Differences in the length and biomass of Douglas-fir shoots were attributed to combined reductions in internode number and internode length (distance between needles), with internode number accounting for most (72–87%) of the variation. The effects of competition from previous years on Douglas-fir growth, as manifested in 1986 bud size or stem circumference, explained 65 and 92% of the variation in 1987 growth of shoots and stem basal area, respectively. The current-year (1987) effects of competition explained an additional 6 and 3%. During the 1986 and 1987 growing seasons, competition limited both the rates and duration of growth of Douglas-fir basal area; for height, only the rates of growth were reduced.

Responses of Pinusbanksiana and Pinusresinosa seedlings to flooding

1983 ◽  
Vol 13 (4) ◽  
pp. 633-639 ◽  
Author(s):  
Z. C. Tang ◽  
T. T. Kozlowski
Keyword(s):  
Shoot Growth ◽  
Dry Weight ◽  
Root Systems ◽  
Height Growth ◽  
Drastic Reduction ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Plant Parts ◽  
Weight Increment ◽  
Growth Production

Flooding of soil for 45 days severely inhibited growth of 115-day-old Pinusbanksiana Lamb, and P. resinosa Ait. seedlings, with significant effects apparent within 15 days after initiation of flooding. Both species adapted poorly to flooding of soil but P. banksiana was more adversely affected than P. resinosa as shown by earlier and more drastic reduction of growth in the former species. In both species flooding decreased the rate of height growth, production of secondary needles, dry weight increment, and relative growth rates of various plant parts. Root growth of both species was reduced more than shoot growth. The reduction in dry weight increment of root systems of both species reflected arrested branching and elongation of roots as well as decay of roots, mainly the very small nonwoody roots. Flooding slightly stimulated ethylene production by submerged stems.

SEASONAL VARIATIONS IN RADIAL GROWTH AT BREAST HEIGHT OF SOME WESTERN HEMLOCK AND DOUGLAS FIR TREES, 1953-57

1960 ◽  
Vol 36 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Braham G. Griffith
Keyword(s):  
Average Length ◽  
Basal Area ◽  
Growing Season ◽  
Average Diameter ◽  
Frost Damage ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Radial Increment ◽  
Breast Height ◽  
Total Growth

Radial increment was recorded at weekly intervals for 68 Douglas fir and 14 western hemlock trees throughout the growing season for the years 1953-57 inclusive. The average diameter, inside bark at breast height, was 13.9 inches for the Douglas firs and 11.9 inches for the western hemlock. Growth for both species generally commenced during the first week of May. The average length of the growing season for Douglas fir was 146 days and for western hemlock 156 days. Douglas fir completed a greater percentage of its total growth earlier in the season than did western hemlock, accounting for an average of 83 per cent of its basal area growth by July 31 compared to 68 per cent for western hemlock. Growth in both 1956 and 1957 was considerably below that of each of the preceding three years. This was attributed partly to the severe frost damage to the trees in November 1955.

Influence of prohexadione calcium (Apogee®) on shoot growth of non-bearing mature apple trees in two different growing regions

2006 ◽  
Vol 86 (1) ◽  
pp. 227-233 ◽  
Author(s):  
J. -P. Privé ◽  
J. Cline ◽  
E. Fava
Keyword(s):  
Growth Rates ◽  
Plant Growth Regulator ◽  
Shoot Growth ◽  
Growth Control ◽  
Seasonal Patterns ◽  
Eastern Canada ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Prohexadione Calcium ◽  
Mature Apple

Orchard experiments were conducted on mature non-bearing apple ( Malus × domesticaBorkh.) trees to determine the efficacy of prohexadione-calcium (PC), formulated as Apogee® [27.5% PC + 56.1% (NH4)2 SO4 +16.4% ot her proprietary additives] for shoot growth control on six cultivars grown in Ontario (ON) and one grown in New Brunswick (NB), Canada. Seasonal patterns of extension shoot growth among cultivars in both locations were also compared. Results indicate that PC applications are most effective at the beginning of the season, when relative growth rates were greatest in eastern Canada. Four applications of PC failed to significantly reduce shoot growth more than two applications in either location. However, the level of control might have been more effective in ON if treatment applications were initiated earlier in the season. Although tree vigor and shoot growth differed between cultivars and locations, PC significantly and consistently reduced shoot growth and relative shoot growth rates for all cultivars at both locations. Empire shoots treated with PC were approximately 33 and 37% shorter at the end of the season in NB and ON, respectively. Key words: Calcium 3-oxido-5-oxo-4-propionylcyclohex-3-enecarboxylate, anti-giberellin, plant growth regulator, relative growth rate, Malus

Early growth of planted western hemlock in relation to stock type and controlled-release fertilizer application

1988 ◽  
Vol 18 (6) ◽  
pp. 710-717 ◽  
Author(s):  
J. T. Arnott ◽  
A. N. Burdett
Keyword(s):  
Growth Rates ◽  
Growing Season ◽  
The Other ◽  
Western Hemlock ◽  
Stem Volume ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
The Third ◽  
Stock Type ◽  
Stock Types

Four types of western hemlock (Tsugaheterophylla (Raf.) Sarg.) nursery stock, differing in size, morphology, and root growth capacity were planted on a clear-cut forest site on Vancouver Island, British Columbia. The stock types were: (i) 1-year-old, plug-rooted seedlings raised in 36-cm3 containers; (ii) as (i) but transplanted to a bareroot nursery for 1 year; (iii) 1-year-old, bareroot seedlings raised in 1000-cm3 containers; (iv) as (iii) but raised in containers coated on the inside with copper paint to inhibit lateral root elongation upon contact with the container wall. Survival and growth of seedlings with and without fertilization at planting with 50 g of a slow-release (Nutricote®, 12-month release at 25 °C) N–P–K fertilizer were observed for 3 years. Neither stock type nor fertilizer had a statistically significant (P < 0.05) effect on seedling survival. At planting, plug seedlings were significantly (P < 0.01) shorter and smaller in stem volume than the other stock types. These differences were no longer evident by the end of the third growing season because of more rapid growth by the plug stock. The largest differences between the plugs and the other stock types in height and diameter relative growth rates occurred during the first growing season. Fertilization significantly (P < 0.01) increased height and stem volume relative growth rates of all stock types during the first growing season. During the third growing season fertilization had a significant (P < 0.01) negative effect on height, and diameter and stem volume relative growth rates of all stock types, but not on absolute rates. At the end of three growing seasons, fertilized trees remained significantly (P < 0.01) larger in all stock types than in the controls.

Physiological indicators of nitrogen response in a short rotation sycamore plantation. II. Nitrogen metabolism

1993 ◽  
Vol 71 (6) ◽  
pp. 841-847 ◽  
Author(s):  
Timothy J. Tschaplinski ◽  
Richard J. Norby
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Nitrate Reductase ◽  
Nitrogen Fertilization ◽  
Free Amino ◽  
Nitrate Reductase Activity ◽  
Growth Response ◽  
Reductase Activity ◽  
Growing Season ◽  
Relative Growth

American sycamore (Platanus occidentalis L.) seedlings were grown in the field under different urea–nitrogen fertilization regimes to identify nitrogen variables that characterize the growth response. Treatments included fertilization with 50, 150, and 450 kg N/ha, periodic fertilization (three times during the growing season) at 37.5 kg N/ha, and an unfertilized control. Leaf total nitrogen concentration was a poor indicator of plant growth response to nitrogen fertilization. Salt-extractable protein, nitrate, and free amino acid concentrations all trended upward by the end of the growing season as relative growth rate declined, but treatment differences were minimal. Leaf nitrate reductase activity was consistently higher in fertilized trees before substantial leaf senescence had occurred. When leaf loss was evident, all treatments had high levels of nitrate reductase activity. Aspartic acid and glutamic acid were the most prevalent free amino acids in leaves, whereas concentrations of amine-rich amino acids were low. Although several nitrogen variables, including foliar asparagine and glycine concentrations, were positively correlated with relative growth rate (r ≥ 0.7), no single variable closely reflected treatment differences in growth response. Key words: amino acids, nitrogen, nitrate reductase, sycamore.

Top pruning Douglas-fir seedlings: morphology, physiology, and field performance

1987 ◽  
Vol 17 (11) ◽  
pp. 1371-1378 ◽  
Author(s):  
Mary L. Duryea ◽  
Steven K. Omi
Keyword(s):  
Pacific Northwest ◽  
Field Performance ◽  
Growing Season ◽  
Cultural Practice ◽  
Douglas Fir ◽  
Field Growth ◽  
Seed Sources ◽  
Full Effect ◽  
Terminal Buds ◽  
Multiple Leaders

Seedlings from nine Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seed sources were top pruned at six nurseries in the Pacific Northwest and then planted at field sites in their own seed zones and on one common site. Seedlings pruned tall (25 cm) and early in the growing season flushed again about 5 weeks after pruning and set bud 2 weeks later than unpruned controls. Nursery yield (number of shippable seedlings) was the same for tall–early pruned and control seedlings; however, pruning increased the number of seedlings with multiple leaders from 10 to 38%. Pruned seedlings were smaller than unpruned seedlings in height, stem diameter, bud length, and root and shoot weights at the time of field planting. First-year field survival and growth were the same for pruned and unpruned seedlings at all planting sites. Second-year field growth of pruned seedlings was generally greater than that of unpruned seedlings, and frequency of multiple leaders was reduced. However, pruned seedlings were still shorter than unpruned ones after 2 years. Field growth was greater when seedlings were pruned early rather than late (end of growing season) and tall rather than short (15 cm). Late–short pruning yielded shorter seedlings with smaller terminal buds and should be avoided. If pruning benefits nurseries by expediting grading, handling, and planting and, perhaps, enhancing growth later in the field, it should be continued as a cultural practice. However, longer-term measurements are needed for assessing the full effect of pruning on seedling growth.

Effects of shading on common waterhemp (Amaranthus rudis) growth and development

Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 898-903 ◽  
Author(s):  
Lawrence E. Steckel ◽  
Christy L. Sprague ◽  
Aaron G. Hager ◽  
F. William Simmons ◽  
German A. Bollero
Keyword(s):  
Growth And Development ◽  
Plant Biomass ◽  
Cropping Systems ◽  
Growing Season ◽  
Viable Seed ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Common Waterhemp ◽  
Amaranthus Rudis ◽  
Vegetative And Reproductive Growth

Common waterhemp is a significant weed problem in Midwestern cropping systems partly because of its potential for multiple emergence events during the growing season. The effects of shade and time of emergence on this weed have not been characterized. In the field, common waterhemp vegetative and reproductive growth were evaluated under different irradiance levels at two emergence times. In full sunlight a common waterhemp plant emerging in late May produced 720 g of biomass and over one million seeds, and a plant emerging in late June produced 350 g of biomass and over 730,000 seeds. Plant biomass and seed production were lower as irradiance levels were decreased to 40, 68, and 99% shade. Mortality was high for common waterhemp grown in 99% shade; however, surviving plants produced some viable seed. Common waterhemp plants grown under reduced irradiance had higher leaf area ratios and lower relative growth rates.

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