Tracheids in white spruce seedling’s long lateral roots in response to nitrogen availability

2000 ◽  
pp. 357-370
Author(s):  
M. J. Krasowski ◽  
J. N. Owens
Keyword(s):  
Nitrogen Availability ◽  
Lateral Roots ◽  
White Spruce

Armillariaostoyae in young spruce plantations

1990 ◽  
Vol 20 (11) ◽  
pp. 1773-1778 ◽  
Author(s):  
William H. Livingston
Keyword(s):  
Black Spruce ◽  
Lateral Roots ◽  
White Spruce ◽  
Root Disease ◽  
Stem Height ◽  
Conifer Seedlings ◽  
Armillaria Root Disease ◽  
Root Collar

Black spruce (Piceamariana (Mill.) B.S.P.) and white spruce (P. glauca (Moench) Voss) plantations, 4–10 years old, were examined for Armillaria root disease. The disease was found in 89% of 27 sample locations, and up to 2% of the trees were recently killed. Armillariaostoyae (Romagn.) Herink was the cause of the disease. Spruce show little reduction in stem height and diameter prior to being killed by the fungus. Lethal infections of A. ostoyae develop primarily at the root collar and are associated with root deformities and small diameters of lateral roots. Root deformities, frequently associated with growing conifer seedlings in containers, are hypothesized to predispose planted spruce to Armillaria root disease.

Competitive effects of woody and herbaceous vegetation in a young boreal mixedwood stand

2008 ◽  
Vol 38 (7) ◽  
pp. 1817-1828 ◽  
Author(s):  
Cosmin D. Man ◽  
Philip G. Comeau ◽  
Douglas G. Pitt
Keyword(s):  
Soil Moisture ◽  
Populus Tremuloides ◽  
Soil Nitrogen ◽  
Picea Glauca ◽  
Nitrogen Availability ◽  
White Spruce ◽  
Soil Nitrogen Availability ◽  
Area Index ◽  
Promising Alternative ◽  
Light Soil

The influence of aspen ( Populus tremuloides Michx.) and herbaceous (forb and grass) vegetation on resource availability and white spruce ( Picea glauca (Moench) Voss) growth were examined as part of a long-term experiment established in 2002 near Whitecourt, Alberta, Canada. During the 2005 growing season, we examined the effects of herbicide treatments designed to control only woody (triclopyr ester) or both woody and herbaceous (glyphosate) vegetation on leaf area index (LAI) of both the woody and herbaceous components and relationships among LAI and light, soil moisture, air temperature, soil temperature, nitrogen availability, and spruce growth. Treatments reduced LAI and increased light, soil nitrogen availability, and white spruce growth. There were no apparent effects of the treatments on soil moisture in 2005. Both the woody and herb–grass layers appear to be competing for light and soil nitrogen in this young plantation. Controlling only woody vegetation resulted in an increase in herbaceous and total LAI (dominated by the grass Calamagrostis canadensis (Michx.) Beauv.). Spot treatment, involving control of vegetation within a 2 m radius of spruce seedlings while leaving 1 m of untreated ground between treated spots, may be a promising alternative to classical broadcast treatments for establishing spruce in a mixedwood stand. Spot treatments provided good growing conditions and reduced exposure of spruce seedlings to summer and winter frost injury during the first 3 years after planting.

scholarly journals Kinetic Parameters of Nitrate Absorption by Adult Coffee Trees

2021 ◽  
Vol 5 ◽  
Author(s):  
César Augusto Avellaneda Bohórquez ◽  
Herminia Emilia Prieto Martinez ◽  
Ricardo Henrique Silva Santos
Keyword(s):  
Kinetic Parameters ◽  
Nitrogen Availability ◽  
Lateral Roots ◽  
Grain Filling ◽  
Woven Fabrics ◽  
Rapid Expansion ◽  
Fresh Matter ◽  
Development Cycle ◽  
Coffee Plants ◽  
High Doses

Nitrogen, the most demanded nutrient by coffee plants, has a rate of recovery from the soil of about 50%. Because of that high doses of nitrogenous fertilizers are used to reach high production, and consequently high amounts of N are lost to the environment. Knowing the kinetic parameters of nitrate (NO3-) absorption over the fruit development cycle is important as a mean of achieve more adjusted fertilizer doses and better recovery rates for the N applied as fertilizers. This study aimed determining the kinetic parameters of NO3- absorption in different development stages of fruits from adult coffee plants. The kinetic parameters Vmax and Km were determined in a low production year, at the pinhead (PH), rapid expansion (RE), grain filling (GF), and maturation (MT) stages. One month before each kinetics assay, lateral roots of eight plants were excavated and wrapped into non-woven fabrics grow cylinders filled in with vermiculite to produce absorbent roots. On the assay day, the roots were washed and immersed into a container with 1 L of 90 μmol L−1 NO3- solution. Sampling began one and a half hours after that, and was taken every hour over 7 h. Data on NO3- depletion were used to calculate the absorption kinetic parameters Vmax and Km. In a low production year the Vmax ranged from 0.14 to 0.72 μmol g−1 h−1 in a root fresh matter basis and Km from 6.47 to 50.31 μmol L−1. The Vmax values were highest at the PH and MT stages; the lowest absorption rate was recorded at GF and Km was lowest at RE. As at the RE stage of fruits Vmax shows a positive correlation with grain production, adequate nitrogen availability must be ensured before this phase to not to affect coming coffee production.

Development of white spruce (Picea glauca) seedling roots

1985 ◽  
Vol 63 (3) ◽  
pp. 456-462 ◽  
Author(s):  
Anne M. Johnson-Flanagan ◽  
John N. Owens
Keyword(s):  
Root System ◽  
Picea Glauca ◽  
Lateral Roots ◽  
Root Apex ◽  
White Spruce ◽  
Growth Cycle ◽  
Root Tip ◽  
System A ◽  
Seedling Roots ◽  
Specific Phase

The root system of container-grown white spruce seedlings (Picea glauca (Moench) Voss) consists of a taproot and many lateral roots. The lateral roots can be divided into three classes on the basis of external morphology. Although growth cycles of individual roots are independent, there are overall trends of growth in the root system. A preponderance of one morphological root class is usually associated with a specific phase of the growth cycle. Apical organization in absorbing and elongating roots is similar. When elongation ceases, roots become brown as a result of two separate processes, suberization of the endodermis and metacutization of a discrete layer enveloping the root apex. Zonation in the apex is reduced in brown roots. Renewed growth is marked by swelling of the brown root apex followed by the emergence of a white root tip.

Root growth and root growth capacity of white spruce (Piceaglauca (Moench) Voss) seedlings

1985 ◽  
Vol 15 (4) ◽  
pp. 625-630 ◽  
Author(s):  
Anne M. Johnson-Flanagan ◽  
John N. Owens
Keyword(s):  
Root Growth ◽  
Root Elongation ◽  
Shoot Growth ◽  
Lateral Roots ◽  
White Spruce ◽  
Shoot Elongation ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
Root And Shoot Growth

Root growth in the root systems of Styroplug-grown white spruce (Piceaglauca (Moench) Voss) seedlings increases in the spring before shoot elongation and again in the fall after bud development is complete. This is followed by root dormancy and quiescence, which are distinguished on the basis of ability to elongate under root growth capacity (RGC) conditions. The number of white long lateral roots produced during RGC tests correlated significantly with the number of white long lateral roots under lathhouse conditions. Increased mitotic activity is required for root elongation. However, mitotic frequencies could not be used to assess RGC because of the confounding effects of independent growth cycles in individual roots. Cell expansion and transformation of insoluble carbohydrates are important controls of root elongation. The relationship between root and shoot growth under RGC conditions may not support the role of shoot elongation in decreasing root elongation. Conversely, this may indicate that RGC tests alter the endogenous controls of root and shoot growth.

Sign in / Sign up

Export Citation Format

Share Document