Peatland and upland black spruce populations in Alberta: morphology and ecophysiology

1993 ◽  
Vol 23 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Zhang M. Wang ◽  
S. Ellen Macdonald
Keyword(s):  
Substrate Temperature ◽  
Black Spruce ◽  
Weight Ratio ◽  
Dry Weight ◽  
Low Light ◽  
Ecotypic Differentiation ◽  
Root Dry Weight ◽  
Habitat Differences ◽  
Net Assimilation ◽  
Full Factorial

Morphology and ecophysiology of black spruce (Piceamariana (Mill.) B.S.P.) seedlings grown in a variety of controlled environments were studied in three pairs of adjacent peatland and upland black spruce populations from Alberta. Seedlings were grown in two greenhouse experiments as follows: (i) full factorial combinations of light (100 or 20% of full light in the greenhouse) and moisture (wet, medium, or dry); (ii) full factorial combinations of fertilization (fertilized or unfertilized) and substrate temperature (20 or 8 °C at 5 cm below the surface). In both experiments, morphological (height, top dry weight, root dry weight, total dry weight, and top/root dry weight ratio) and physiological (net assimilation (NA), stomatal and mesophyll conductance to CO2 (gc and gm), and water use efficiency (WUE)) traits were measured. It was found that low light, nutrient stress, and water stress (wet or dry) reduced seedling growth. As moisture decreased or at low light, NA, gc, gm, and WUE decreased. When fertilized, seedlings at low substrate temperature were smaller and had lower NA, gc, and gm than those at high substrate temperature. Results showed no differences in response to the experimental environments between seedlings from peatland versus upland populations. However, upland seedlings were larger than peatland ones, there was greater variation among peatland than among upland populations, and there were site-specific habitat differences. Overall, there was apparently little adaptive ecotypic differentiation in black spruce between the two habitats.

Responses of jack pine and black spruce seedlings to inoculation with selected species of ectomycorrhizal fungi

1991 ◽  
Vol 21 (5) ◽  
pp. 701-706 ◽  
Author(s):  
Mark H. R. Browning ◽  
Roy D. Whitney
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Black Spruce ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Systems ◽  
Jack Pine ◽  
Fungal Species ◽  
Short Root ◽  
Root Dry Weight ◽  
Aseptic Culture

Seedlings of jack pine (Pinusbanksiana Lamb.) and black spruce (Piceamariana (Mill.) B.S.P.) were inoculated with liquid cultures of fragmented hyphae of 10 species of ectomycorrhizal fungi and grown in either aseptic culture tubes for 20 weeks or nonaseptic pots for 16 weeks. Seedlings in pots received more total nutrients and produced larger root systems than those in tubes. Four of the fungi produced higher levels of colonization associated with these larger root systems. Short-root density of black spruce was increased compared with that of uninoculated seedlings by inoculation with Laccariabicolor (Maire) Orton, Hebelomacylindrosporum Romagnési, or Thelephoraterrestris Ehrh. ex Fr. Colonization of jack pine by Rhizopogonrubescens (Tul.) Tulasne, L. bicolor, H. cylindrosporum, or Pisolithustinctorius (Pers.) Coker & Couch resulted in greater short-root densities than in uninoculated controls. Inoculation of potted black spruce with Laccariaproxima Boudier resulted in larger shoot weights and those inoculated with H. cylindrosporum had smaller root weights than did uninoculated seedlings. Both fungi resulted in increased shoot/root dry-weight ratios in black spruce. In contrast with black spruce, seedling weights were not affected by inoculation of jack pine with the same fungal species. However, inoculation of jack pine with R. rubescens resulted in a significantly higher shoot/root dry-weight ratio.

scholarly journals Needle-Clipping Longleaf Pine and Top-Pruning Loblolly Pine in Bareroot Nurseries

1998 ◽  
Vol 22 (4) ◽  
pp. 235-240 ◽  
Author(s):  
David B. South
Keyword(s):  
Loblolly Pine ◽  
Seedling Survival ◽  
Longleaf Pine ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Weight ◽  
Root Weight Ratio ◽  
Root Dry Weight ◽  
Percentage Points ◽  
Average Survival

Abstract Studies have shown that clipping needles of longleaf pine before outplanting can increase average seedling survival by 13 percentage points. Under some situations, the increase in survival might be due to a reduction in transpiration. For loblolly pine, top-pruning in the nursery might increase average survival by 6 percentage points. Benefits of pruning appear greater when seedlings experience stress after planting and when nonpruned seedlings have low root weight ratios (root dry weight/total seedling dry weight). On some droughty sites, a seedling with a 0.3 root weight ratio might have an 80% chance of survival, while a seedling with a 0.2 root weight ratio might only have a 53% chance of survival. In most studies where heights were measured after 3 yr in the field, pruned seedlings were the same height as nonpruned seedlings (± 7 cm). South. J. Appl. For. 22(4):235-240.

scholarly journals Effects of Nitrogen, Phosphorus, Potassium, Calcium, or Magnesium Deficiency on Growth and Photosynthesis of Eustoma

HortScience ◽  
2018 ◽  
Vol 53 (6) ◽  
pp. 795-798 ◽  
Author(s):  
Chang-Tsern Chen ◽  
Ching-Lung Lee ◽  
Der-Ming Yeh
Keyword(s):  
Magnesium Deficiency ◽  
Weight Ratio ◽  
Carbon Dioxide Concentration ◽  
Dry Weight ◽  
Photosynthetic Parameters ◽  
Eustoma Grandiflorum ◽  
Node Number ◽  
Mg Deficiency ◽  
Root Dry Weight ◽  
Shoot Dry Weight

Growth and photosynthetic parameters were measured in Eustoma grandiflorum (Raf.) Shinn. ‘Umihonoka’ grown hydroponically under nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), or magnesium (Mg) deficiency in 1/2 strength of modified Johnson’s solution. Plant height, node number, and leaf area were all reduced under N, P, K, and Ca deficiencies but not under Mg deficiency as compared with plants grown in the complete nutrient solution. Shoot and root dry weight were reduced in the N-, P-, K-, and Ca-deficient treatments, whereas root but not shoot dry weight was lowered by Mg-deficient treatment. Shoot-to-root dry weight ratio decreased under N and P deficiencies, increased under K and Mg deficiency, but was not altered under Ca deficiency. Decreased net photosynthetic rate (Pn) of N-, P-, and K-deficient leaves was all related to lower stomatal conductance (gS), whereas N-deficient leaves also accompanied by a higher intercellular carbon dioxide concentration (Ci). The Mg-deficient treatment did not alter chlorophyll fluorescence Fv/Fm, maximal fluorescence (Fm), or minimal fluorescence (Fo). Decreased Fv/Fm of N-, P-, K-, and Ca-deficient leaves was all related to lower Fm, whereas N- and P-deficient leaves also accompanied by lower Fo. A key was developed for the identification of N, P, K, Ca, and Mg deficiency symptoms.

scholarly journals Increasing Cell Size and Reducing Medium Compression Enhance Lettuce Transplant Quality and Field Production

HortScience ◽  
1996 ◽  
Vol 31 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Silvana Nicola ◽  
Daniel J. Cantliffe
Keyword(s):  
Cell Size ◽  
Sandy Soil ◽  
Shoot Growth ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Weight ◽  
Growth Ratio ◽  
Root Dry Weight ◽  
Total Dry Weight ◽  
Initial Root

`South Bay' lettuce (Lactuca sativa L.) seedlings were grown in a greenhouse during winter, spring, and fall to investigate the effect of cell size and medium compression on transplant quality and yield. Four Speedling planter flats (1.9-, 10.9-, 19.3-, 39.7-cm3 cells) and two medium compression levels [noncompressed and compressed (1.5 times in weight)] were tested. The two larger cell sizes and compression of the medium led to increased plant shoot growth. Conversely, root weight ratio [RWR = (final root dry weight ÷ final total dry weight + initial root dry weight ÷ initial total dry weight) ÷ 2] was highest with the smaller cells without medium compression. Lettuce transplants were field-grown on sand and muck soils. The larger cells delayed harvest by >2 weeks for plants grown on muck soil, but yield was unaffected. When grown on sandy soil, earliness was enhanced from plants grown in 19- and 40-cm3 cells, but head weights were not affected in the spring planting. In fall, heads were heavier for plants grown in 11-, 19-, or 40-cm3 cells compared with those from 2-cm3 cells. On sandy soil, harvest was delayed 13 days in spring and 16 days in fall for plants grown in the smallest cell size. Using the two smaller cell sizes saved medium and space in the greenhouse and increased the root growth ratio, but it led to reduced plant growth compared to using the bigger cells. Yield and earliness were more related to season and soil type than to transplant quality. On sandy soil, plants grown in 2- and 11-cm3 cells matured later, and yield was significantly decreased (8.6%) in fall by using plants from the 2-cm3 cells compared to the other sizes. From our results, compressing the medium in the cells was not justified because it is more costly and did not benefit yield in the field.

scholarly journals Seedling Growth of Catawba Rhododendron. I. Temperature Optima, Leaf Area, and Dry Weight Distribution

HortScience ◽  
1994 ◽  
Vol 29 (11) ◽  
pp. 1298-1302 ◽  
Author(s):  
D. Bradley Rowe ◽  
Stuart L. Warren ◽  
Frank A. Blazich
Keyword(s):  
Leaf Area ◽  
Seedling Growth ◽  
Weight Ratio ◽  
Dry Weight ◽  
High Elevation ◽  
Root Weight ◽  
Root Dry Weight ◽  
Leaf Weight Ratio ◽  
Leaf Weight ◽  
Total Plant

Catawba rhododendron (Rhododendron catawbiense Michx.) seedlings of two provenances, Johnston County, N.C. (35°45′N, 78°12′W, elevation = 67 m), and Yancey County, N.C. (35°45′N, 82°16′W, elevation = 1954 m), were grown in controlled-environment chambers for 18 weeks with days at 18, 22, 26, or 30C in factorial combination with nights at 14, 18, 22, or 26C. Shoot and root dry weights and total leaf areas of seedlings of the Yancey County provenance (high elevation) exceeded (P ≤ 0.05) those of the Johnston County (low elevation) provenance at all temperature combinations. Leaf area was maximal at 22/22C, 18/26C, and 22/26C and minimal at 30/14C (day/night). Shoot dry weight responded similarly. Root dry weight decreased linearly with increasing day temperature, but showed a quadratic response to night temperature. Leaf weight ratio (leaf dry weight: total plant dry weight) increased, while root weight ratio (root dry weight: total plant dry weight) decreased with increasing day temperature. Leaf weight ratio was consistently higher than either stem or root weight ratios. Day/night cycles of 22 to 26/22C appear optimal for seedling growth.

scholarly journals Sewage sludge and rice husk as potential substrate to produce Mimosa setosa seedlings

2020 ◽  
Vol 7 (3) ◽  
pp. 1111-1119
Author(s):  
Julio Cezar Tannure Faria ◽  
Marcos Vinícius Winckler Caldeira ◽  
William Macedo Delarmelina ◽  
Erick Martins Nieri ◽  
Denys Santana Souza ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Rice Husk ◽  
Dry Matter ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Collar Diameter ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Collar Diameter ◽  
Root Collar

In the production of forest seedlings one of the main factors to be analyzed is the formulation of the substrate that meets the needs of the plants that will be produced. For this, the choice of substrate must consider the physical characteristics of the material, its chemical composition, as well as its availability, quality, easy handling and cost. This study aimed to investigate the potential of sewage sludge and rice husk for the production of seedlings of Mimosa setosa. The experiment was conducted in structures of a forest nursery, localized in the municipality of Alegre-ES, in 110 cm³ tubes arranged in a completely randomized design constituted by ten treatments with four replications of 54 seedlings per plot. The treatments were formulated using sewage sludge, raw rice husks and carbonized rice husk. At five months after sowing we measured plant height, root collar diameter, height/diameter ratio, shoot dry weight, root dry weight, total dry matter, shoot to root dry weight ratio and Dickson Quality Index. The substrates formulated with carbonized rice husk promoted the best results for all morphological characteristics analyzed. The multivariate analysis showed higher correlation of treatments with carbonized rice husk (T6, T7, T8 and T9) regarding height, root collar diameter, root dry weight, shoot dry weight and total dry matter. For the production of Mimosa setosa seedlings the best responses resulted from the substrate formulated with 60% sewage sludge + 40% carbonized rice husk.

scholarly journals Growth Analysis and Photosynthesis Measurements of Cucumber Seedlings Grown under Light with Different Red to Far-red Ratios

HortScience ◽  
2016 ◽  
Vol 51 (7) ◽  
pp. 843-846 ◽  
Author(s):  
Toshio Shibuya ◽  
Ryosuke Endo ◽  
Yoshiaki Kitaya ◽  
Saki Hayashi
Keyword(s):  
Leaf Area ◽  
Growth Parameters ◽  
Weight Ratio ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Unit Leaf Area ◽  
Cucumber Seedlings ◽  
Unit Leaf ◽  
Net Assimilation ◽  
Normal Light

Light with a higher red to far-red ratio (R:FR) than sunlight reduces plant growth, but the cause has not been firmly established. In the present study, cucumber seedlings were grown under normal light (similar to sunlight; R:FR = 1.4) from metal-halide lamps or high-R:FR light (R:FR = 4.3) created by transmitting their light through FR-absorbing film, and then their growth parameters and photosynthesis were compared. The relative growth rate (RGR) at high R:FR was 92% of that under normal R:FR, although the net assimilation rate (NAR) did not differ between the treatments, indicating that changes in net photosynthesis per unit leaf area did not cause the growth inhibition at high R:FR. The CO2 exchange per unit leaf area did not differ between the treatments, which supports this hypothesis. The leaf area ratio (LAR) of total plant dry weight of high R:FR seedlings to that of normal R:FR seedlings was also 92%. This suggests that growth suppression in the high R:FR seedlings was caused mainly by decreased LAR. The specific leaf area (SLA) and leaf weight ratio (LWR), components of LAR, under high-R:FR light were 89% and 105%, respectively, of those under normal light, indicating that the smaller LAR at high R:FR mainly results from suppressed leaf enlargement per unit leaf dry matter.

scholarly journals Growth analyses of tomato genotypes grown under low energy conditions.

1991 ◽  
Vol 39 (3) ◽  
pp. 191-196 ◽  
Author(s):  
M. Nieuwhof ◽  
F. Garretsen ◽  
J.C. van Oeveren
Keyword(s):  
Leaf Area ◽  
Weight Ratio ◽  
Energy Conditions ◽  
Genotypic Differences ◽  
Low Light ◽  
Strong Negative Correlation ◽  
Plant Weight ◽  
Relative Growth ◽  
Net Assimilation ◽  
Growth Analyses

Growth analyses were carried out on young plants of 15 genotypes, grown initially at 19/14 degrees C day/night temperatures for an 8 h day at low light intensity and subsequently at the night temperatures of 6, 10 and 14 degrees C. Significant genotypic differences occurred for relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf weight ratio (LWR). RGR, LAR and SLA increased and LWR decreased at higher night temperatures. A strong negative correlation was observed between NAR and LAR and NAR and SLA whilst a positive correlation was noted between LAR and SLA. Plant weight was strongly influenced by seed size. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Factors affecting growth and reproduction of Noogoora burr (Xanthium occidentale Bertol.)

1984 ◽  
Vol 35 (2) ◽  
pp. 271 ◽  
Author(s):  
RJ Martin ◽  
JA Carnahan
Keyword(s):  
Plant Density ◽  
Unit Area ◽  
Dry Weight ◽  
Low Light ◽  
Factors Affecting ◽  
Shoot Dry Weight ◽  
High Plant Density ◽  
Low Levels ◽  
Net Assimilation ◽  
Growth And Reproduction

Plant density and availability of light and water significantly affected growth and reproduction of Noogoora burr plants grown in a glasshouse. Burr yield was reduced most by low levels of available water. Low light intensity, low water availability and high plant density reduced net assimilation rates and, in combination, caused the greatest reduction in burr production. Under field conditions the ratio of burr dry weight to total shoot dry weight decreased with increasing plant density. In terms of production per unit area, dry weight of main stems and main stem leaves increased with increasing plant density at the expense of burr dry weight. We conclude that the success of Noogoora burr as a fleece contaminant could be attributed, in part, to: the insensitivity of burr production to variation in soil fertility and length of growing season; the ability to regulate plant density under conditions of limiting light or water; and the ability to regulate plant components so that the efficiency of burr production increases with a decrease in plant density.

scholarly journals Growth of tomato seedlings in substrates containing a nanocomposite hydrogel with calcium montmorillonite (NC-MMt)

2019 ◽  
Vol 37 (2) ◽  
pp. 199-203
Author(s):  
Raphael AC Melo ◽  
Marçal HA Jorge ◽  
Adriel Bortolin ◽  
Leonardo S Boiteux ◽  
Caue R Oliveira ◽  
...  
Keyword(s):  
Plant Height ◽  
Weight Ratio ◽  
Dry Weight ◽  
Pine Bark ◽  
Peat Moss ◽  
Water Retention Capacity ◽  
Nanocomposite Hydrogel ◽  
Tomato Seedlings ◽  
Root Dry Weight ◽  
Shoot Dry Weight

ABSTRACT The correct use of hydrogels in some situations can increase seedling survival rates, plant growth, and the water-retention capacity of the growing medium. A technique for the production of a nanocomposite hydrogel using calcium montmorillonite (NC-MMt) was recently developed. However, additional research is necessary in order to validate this innovative input, particularly for the production of vegetable crops seedlings. In this context, the main objective of the present study was to evaluate the growth and development of seedlings, tomato hybrid ‘BRS Nagai’, in substrates containing different amendments of hydrogel NC-MMt. The trial was conducted in a 3x3 factorial arranged in a complete randomized blocks design, with three replications. Three substrates (peat moss, pine bark, and coconut peat) corresponded to the first factor and three rates of the NC-MMt hydrogel (0%= R1, 1.5%= R2 and 2.0%= R3, on a w/w basis) corresponded to the second factor. Each plot was composed of 16 plants that were assessed after three weeks. Overall, peat moss-based and pine bark-based substrates resulted in higher values for most of the analyzed traits: plant emergency percentage, plant height, stem diameter, leaf area, plant height/shoot dry weight ratio, root dry weight, shoot dry weight/root dry weight ratio and the Dickinson Quality Index. Rates of NC-MMt hydrogel displayed significant responses only to root superficial area and root volume. NC-MMt hydrogel amendment (mainly 1.5%) combined with specific substrates (mainly peat moss-based substrate) was able to improve the growth of ‘BRS Nagai’ tomato seedlings, with no observed toxic effects.

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