scholarly journals Nodal root diameter and node number in maize (Zea mays L.) interact to influence plant growth under nitrogen stress

2020 ◽  
Author(s):  
Hannah M. Schneider ◽  
Jennifer T. Yang ◽  
Kathleen M. Brown ◽  
Jonathan P. Lynch
Keyword(s):  
Shoot Growth ◽  
Cross Sectional Area ◽  
Nitrogen Stress ◽  
Sectional Area ◽  
Root Number ◽  
Cross Sectional ◽  
Nitrogen Acquisition ◽  
Nodal Roots ◽  
Nodal Root ◽  
Low Nitrogen

AbstractUnder nitrogen limitation, plants increase resource allocation to root growth relative to shoot growth. The utility of various root architectural and anatomical phenotypes for nitrogen acquisition are not well understood. Nodal root number and root cross-sectional area were evaluated in maize in field and greenhouse environments. Nodal root number and root cross-sectional area were inversely correlated under both high and low nitrogen conditions. Attenuated emergence of root nodes, as opposed to differences in the number of axial roots per node, was associated with substantially reduced root number. Greater root cross-sectional area was associated with a greater stele area and number of cortical cell files. Genotypes that produced few, thick nodal roots rather than many, thin nodal roots had deeper rooting and better shoot growth in low nitrogen environments. Fewer nodal roots offset the respiratory and nitrogen costs of thicker diameter roots, since total nodal root respiration and nitrogen content was similar for genotypes with many, thin and few, thick nodal roots. We propose that few, thick nodal roots may enable greater capture of deep soil nitrogen and improve plant performance under nitrogen stress. The interaction between an architectural and anatomical trait may be an important strategy for nitrogen acquisition. Understanding trait interactions among different root nodes has important implications in for improving crop nutrient uptake and stress tolerance.

scholarly journals Comparative Vegetative Growth Responses of Two Peach Cultivars Grown on Size-controlling versus Standard Rootstocks

2003 ◽  
Vol 128 (4) ◽  
pp. 463-471 ◽  
Author(s):  
Antonio Weibel ◽  
R. Scott Johnson ◽  
Theodore M. DeJong
Keyword(s):  
Vegetative Growth ◽  
Shoot Growth ◽  
Prunus Persica ◽  
Size Control ◽  
Cross Sectional Area ◽  
Extension Growth ◽  
Sectional Area ◽  
Growth Responses ◽  
Cross Sectional ◽  
The University

Vegetative growth of two peach (Prunus persica L. Batsch) cultivars Flavorcrest and Loadel growing on six different rootstocks (`Nemaguard', `Hiawatha', K-146-43, K-146-44, P-30-135, and K-119-50) was analyzed during the third season of growth in an experimental orchard at the University of California Kearney Agricultural Center near Parlier, California. Seasonal trunk cross-sectional area, shoot and internode growth, diurnal stem extension growth rate and summer and dormant pruning weights were measured to determine extent of size-control imparted by the experimental rootstocks compared to the trees on the `Nemaguard' control and to characterize the nature of the sizecontrolling response. Trunk cross-sectional area growth of trees on the two smallest rootstocks (K-146-43 and K-146-44) was only 25% to 37% of the growth of trees on `Nemaguard', while trees on the other three rootstocks provided an intermediate level of size control. Generally, the seasonal patterns of shoot growth did not vary substantially among trees on the different rootstocks, but average shoot and internode lengths did correspond with tree size. Vigorous watersprout growth was decreased by more than 80% in the trees on the least vigorous rootstocks compared to trees on `Nemaguard' resulting in major reductions in the extent of summer and winter pruning weights. Variations in vegetative shoot growth appeared to correspond to variations in daily shoot extension growth rates but more research is needed to explore these relationships.

scholarly journals Production Method and Irrigation Effects Postplanting Root Morphology of Quercus virginiana

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 605f-606
Author(s):  
Michael D. Marshall ◽  
Edward F. Gilman
Keyword(s):  
Sandy Soil ◽  
Production Method ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Root Number ◽  
Irrigation Frequency ◽  
Cross Sectional ◽  
Trunk Diameter ◽  
Quercus Virginiana ◽  
Irrigation Effects

Quercus virginiana trees were container-grown (CG) or field-grown (FG) to a mean trunk diameter of 9.4 cm (3.7 inches), transplanted into sandy soil, and established with frequent or periodic irrigation. Three years after transplanting, trees were harvested with a 1.5-m- (60-inch-) diameter tree spade. Root number and root cross-sectional area was evaluated at the periphery of the tree spade-dug root ball. Despite similar increases in trunk diameter, FG trees had greater root number and root cross-sectional area than CG trees. The increase in root cross-sectional area occurred for roots 5 to 20 mm in diameter at the 0- to 25-cm and 75- to 100-cm soil depths. Irrigation frequency after transplanting had no effect on root number in FG trees; however, root number in CG trees decreased without frequent irrigation.

scholarly journals Influence of Paclobutrazol on Shoot Growth and Flowering in a High-density Pecan Orchard

2019 ◽  
Vol 29 (2) ◽  
pp. 210-212
Author(s):  
Haijun Zhu ◽  
Eric T. Stafne
Keyword(s):  
Shoot Growth ◽  
Carya Illinoinensis ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Single Application ◽  
Cross Sectional ◽  
Current Season ◽  
Long Shoots ◽  
Short Shoots ◽  
Terminal Shoot

Paclobutrazol (PBZ) was applied to 6-year-old pecan (Carya illinoinensis) trees as a basal trunk drench (0, 30, 90, and 150 mg·cm−2 trunk cross-sectional area) in Dec. 2012. Terminal shoot growth was retarded for 1 year after a single application of PBZ. The total number of current season shoots showed a significant increase with 30- and 90-mg·cm−2 PBZ treatments. After PBZ application at 30, 60, and 90 mg·cm−2, the percentage of very short shoots (<5 cm) was 32.3%, 36.3%, and 32.3%, respectively, compared with 22.4% on control trees; the percentage of short shoots (5–15 cm) increased to 36.0%, 38.1%, and 43.5%, respectively. The percent of long shoots (>30 cm) was decreased to 7.4%, 5.1%, and 7.6%, respectively, after PBZ application, compared with 18.7% with control. Shoots varying from 5 to 30 cm in length accounted for at least 63.3% of all pistillate inflorescences the following spring.

scholarly journals Establishment, Growth, and Foliar Nutrient Content of Plum Trees on Various Rootstocks

HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 219-221 ◽  
Author(s):  
G.E. Boyhan ◽  
J.D. Norton ◽  
J.A. Pitts
Keyword(s):  
Multiple Regression ◽  
Shoot Growth ◽  
Nutrient Content ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Prunus Salicina ◽  
Tree Survival ◽  
Foliar Nutrient

The dwarfing characteristics of St. Julien and Pixy rootstocks, measured by shoot growth, were evident with `AU-Amber' and `AU-Producer' plum (Prunus salicina Lindl.) scions. Dwarfing did not occur with `AU-Rubrum'. Trunk cross-sectional area (TCA) was reduced with `AU-Amber', `AU-Producer', and `AU-Rubrum' scions on St. Julien and Pixy rootstocks. After 3 years, tree survival was 94% for Lovell; 89%, Halford; 57%, Nemaguard; 75%, Nemared; 83%, St. Julien; and 47%, Pixy. Tree survivability was significantly lower on Nemaguard and Pixy rootstocks than on Lovell and Halford. Multiple regression of total shoot growth, TCA, and survivability against foliar nutrient content resulted in the following significant equations: 0.460Mg - 0.210Mn, 0.236B - 0.487Mn, and 0.359N + 0.398Ca - 0.267P - 0.360Fe for each, respectively. Growth, survivability, and foliar nutrient content are significantly affected by rootstock in plum production.

scholarly journals Drought Response of Young Apple Trees on Three Rootstocks: Growth and Development

1997 ◽  
Vol 122 (1) ◽  
pp. 14-19 ◽  
Author(s):  
R. Thomas Fernandez ◽  
Ronald L. Perry ◽  
James A. Flore
Keyword(s):  
Growth Rate ◽  
Drought Stress ◽  
Shoot Growth ◽  
Leaf Growth ◽  
Recovery Period ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Current Season ◽  
Leaf Emergence

`Imperial Gala' apple (Malus domestica Borkh.) trees, trained to two shoots, on M.9 EMLA, MM.111, and Mark rootstocks were subjected to two drought-stress and recovery periods in a rainshelter. Leaf growth rate, leaf area, leaf emergence, shoot length, and trunk cross-sectional area were measured during each stress and recovery period. Leaf growth rate was reduced during both stress periods but most consistently during the second drought stress. Length of the less-vigorous shoot was reduced most consistently due to drought stress but did not recover upon irrigation. Leaf emergence and trunk cross-sectional area increment were inconsistent in response to stress. Tree growth was reduced by drought stress to the greatest extent for trees on Mark, with MM.111 intermediate and M.9 EMLA least affected. At termination, the plants were separated into roots, current-season shoot growth, previous-season shoot growth, and rootstock, and dry weights were measured. Dry weights confirmed the growth measurements taken during the experiment with a 16%, 27%, and 34% reduction in total plant dry weight for drought-stressed trees on M.9 EMLA, MM.111, and Mark, respectively, compared to corresponding controls. It was concluded that Mark was the most sensitive of the three rootstocks followed by MM.111; M.9 EMLA was the most drought resistant.

scholarly journals Production Method and Irrigation Affect Root Morphology of Live Oak

1997 ◽  
Vol 15 (2) ◽  
pp. 84-87
Author(s):  
Michael D. Marshall ◽  
Edward F. Gilman
Keyword(s):  
Sandy Soil ◽  
Production Method ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Root Number ◽  
Irrigation Frequency ◽  
Cross Sectional ◽  
Trunk Diameter ◽  
Quercus Virginiana ◽  
Live Oak

Abstract Trees of live oak (Quercus virginiana Mill.) were container-grown (CG) or field-grown (FG) to a mean trunk diameter of 9.4 cm (3.7 in), transplanted into sandy soil, and established with frequent or periodic irrigation. Three years after transplanting, trees were harvested with a 1.5 m (60 in) diameter tree spade. Root number and root cross-sectional area was evaluated for all roots at the periphery of the tree-spade-dug root ball. Despite similar increases in trunk diameter, FG trees had greater root number and root cross-sectional area than CG trees. The greater root cross-sectional area occurred in roots 5–20 mm (0.2–0.8 in) in diameter at soil depths of 0–25 cm (0–9.8 in) and 75–100 cm (29.5–39.3 in). Irrigation frequency after transplanting had no effect on root number in FG trees. However, root number in CG trees was lower without frequent irrigation.

scholarly journals EFFECT OF ROOTSTOCK ON LONGEVITY AND FRUIT AND TREE CHARACTERISTICS OF PLUM

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 431d-431
Author(s):  
J.D. Norton ◽  
G.E. Boyhan ◽  
J.A. Pitts
Keyword(s):  
Multiple Regression ◽  
Shoot Growth ◽  
Cross Sectional Area ◽  
Regression Equations ◽  
Sectional Area ◽  
Cross Sectional ◽  
Nutrient Analysis ◽  
Tree Survival ◽  
Foliar Nutrient ◽  
Tree Characteristics

The dwarfing characteristics of St. Julien and Pixy rootstocks as measured by shoot growth and trunk cross-sectional area (TCSA) was evident. Tree survival was significantly reduced after 3 years on Nemaguard and Pixy rootstocks. None of the elements measured by foliar nutrient analysis were below the minimum for plums; however, significant multiple regression equations for total shoot growth, TCSA, and survivability were evident with R2 of ≈0.30 in all three cases.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

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