Variation among Red and Freeman Maples in Response to Drought and Flooding

Freeman maples (Ace×freemanii E. Murray) are marketed as stress-resistant alternatives to red maples (Acer rubrum L.). Our objective was to compare two cultivars of Freeman maple [`Jeffersred' (Autumn Blaze®) and `Indian Summer'] and five red maples [`Franksred' (Red Sunset®), `Autumn Flame', `PNI 0268' (October Glory®), `Fairview Flame', and unnamed selection 59904] for effects of flooding and water deficit on plant growth, biomass partitioning, stomatal conductance, and leaf osmotic potential. Plants grown from rooted cuttings in containers were subjected to three consecutive cycles during which root-zone water content decreased to 0.12, 0.08, and 0.02 m3·m–3, respectively. Additional plants were flooded for 75 days, while plants in a control treatment were irrigated frequently. Stomatal conductance immediately before imposing drought and after three drought cycles did not differ among genotypes and averaged 220 and 26 mmol·s–1·m–2, respectively. Differences in stomatal conductance after recovery from the first drought cycle and at the end of the second drought cycle did not vary with species. Drought reduced estimated leaf osmotic potential similarly for all genotypes; means for drought-stressed and control plants were –1.92 and –1.16 MPa, respectively. Freeman maples had a higher mean root: shoot weight ratio and a lower leaf surface area: root dryweight ratio than did red maples. Across genotypes, stomatal conductance of flooded plants initially increased by ≈20% and then fell to and remained below 50 mmol·s–1·m–2. Stomatal conductance of `Indian Summer' decreased to ≈20 mmol·s–1·m–2 after 8 days of flooding, indicating that this cultivar may be particularly sensitive to root-zone saturation.

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Drought Resistance among Freeman Maples

HortScience ◽

10.21273/hortsci.32.3.508c ◽

1997 ◽

Vol 32 (3) ◽

pp. 508C-508

Author(s):

James A. Zwack ◽

William R. Graves ◽

Alden M. Townsend

Keyword(s):

Root Zone ◽

Acer Rubrum ◽

Dry Mass ◽

Red Maple ◽

Specific Mass ◽

Volume Curve ◽

Leaf Surface Area ◽

As Stress ◽

Few Data ◽

Shoot Mass

Freeman maples (Acer × freemanii E. Murray) are marketed as stress-resistant alternatives to red maples (Acer rubrum L.), but few data from direct comparisons of these species are available. As a first step in comparing the stress resistance of red maple and Freeman maple, responses to drought were studied in Acer × freemanii `Autumn Fantasy', `Celebration', and `Marmo'. Plants grown from rooted cuttings were treated by withholding irrigation through four drought cycles of increasing severity that were separated by irrigation to container capacity. Drought reduced shoot dry mass, root dry mass, and height growth by 64%, 43%, and 79%, respectively, over all cultivars. Predawn leaf water potential was reduced by 1.16 MPa over all cultivars, and stomatal conductance data indicated water use was more conservative over all root-zone moisture contents after repeated cycles of drought. Specific mass of drought-stressed leaves increased by 25% for `Autumn Fantasy', and microscopy to determine leaf thickness and cellular anatomy is ongoing. `Autumn Fantasy' also had the lowest ratio of leaf surface area to xylem diameter, and `Autumn Fantasy' and `Celebration' had higher ratios of root to shoot mass than `Marmo'. Pressure-volume curve analysis revealed osmotic potential of drought-stressed plants at full turgor was 0.24 MPa more negative than controls, and droughted plants had a greater apoplastic water percentage than controls. Although osmotic adjustment during drought was similar among cultivars, differences in specific mass of leaves and in ratios of transpiring and conducting tissues suggest cultivars of Freeman maple vary in resistance to drought in the landscape.

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Physiological Responses of Three Grapevine Cultivars to Partial Root Drying

HortScience ◽

10.21273/hortsci.41.4.1011c ◽

2006 ◽

Vol 41 (4) ◽

pp. 1011C-1011

Author(s):

Said Ennahli ◽

Sorkel Kadir

Keyword(s):

Stomatal Conductance ◽

Root System ◽

Fruit Quality ◽

Root Zone ◽

Plant Root ◽

Irrigation Management ◽

Substantial Reduction ◽

Growth Yield ◽

Control Treatment ◽

Plant Root System

Partial root-zone drying (PRD) irrigation management has been developed for grapevines as an efficient method to control excessive growth, improve fruit quality, and save water without compromising yield. PRD is based on knowledge of the mechanisms that control transpiration and requires slow dehydration of half of the plant root system, whereas the other half is irrigated. A study was conducted in the field to evaluate the effect of PRD on physiological characteristics, growth, yield, and fruit quality of three grape cultivars. The wetting and drying cycle of the PRD-vine root system is alternated on a 10–14 day schedule. Significant reduction in vigor was observed in treated plants compared with control plants. Root biomass was not affected, but fine roots significantly increased in PRD-treated plants, compared with that of the control. This contributed to the ability of PRD-treated plants to maintain leaf water potential similar to that of the control. Stomatal conductance of PRD plants was significantly reduced when compared with that of the control plants. Abscisic acid (ABA) concentration in leaves of PRD vines increased significantly when compared to the control vines. PRD treatment significantly increased yield and fruit quality when compared with the control treatment. PRD significantly increased water use efficiency (pruning weight per unit of water applied). This study shows that PRD stimulated ABA production in the drying roots, which caused reduction in stomatal conductance and transpiration rate, leading to a substantial reduction in vegetative growth without compromising yield and fruit quality.

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Drought Avoidance in Katsura by Drought-induced Leaf Abscission and Rapid Refoliation

HortScience ◽

10.21273/hortsci.34.5.871 ◽

1999 ◽

Vol 34 (5) ◽

pp. 871-874 ◽

Cited By ~ 1

Author(s):

Michael S. Dosmann ◽

William R. Graves ◽

Jeffery K. Iles

Keyword(s):

Surface Area ◽

Leaf Surface ◽

Weight Ratio ◽

Dry Weight ◽

Leaf Abscission ◽

Control Treatment ◽

Drought Treatment ◽

Temporary Reduction ◽

Leaf Surface Area ◽

Leaf Dry Weight

The limited use of the katsura tree (Cercidiphyllum japonicum Sieb. & Zucc.) in the landscape may be due to its reputed, but uncharacterized, intolerance of drought. We examined the responses of katsura trees subjected to episodes of drought. Container-grown trees in a greenhouse were subjected to one of three irrigation treatments, each composed of four irrigation phases. Control plants were maintained under well-hydrated conditions in each phase. Plants in the multiple-drought treatment were subjected to two drought phases, each followed by a hydration phase. Plants in the single-drought treatment were exposed to an initial drought phase followed by three hydration phases. Trees avoided drought stress by drought-induced leaf abscission. Plants in the multiple- and single-drought treatments underwent a 63% and 34% reduction in leaf dry weight and a 60% and 31% reduction in leaf surface area, respectively. After leaf abscission, trees in the single-drought treatment recovered 112% of the lost leaf dry weight within 24 days. Leaf abscission and subsequent refoliation resulted in a temporary reduction in the leaf surface area: root dry weight ratio. After relief from drought, net assimilation rate and relative growth rate were maintained at least at the rates associated with plants in the control treatment. We conclude that katsura is a drought avoider that abscises leaves to reduce transpirational water loss. Although plants are capable of refoliation after water becomes available, to maintain the greatest ornamental value in the landscape, siting of katsura should be limited to areas not prone to drought.

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599 Flooding Effects on Stomatal Conductance and Leaf Color Vary among Genotypes of Red and Freeman Maples

HortScience ◽

10.21273/hortsci.34.3.550c ◽

1999 ◽

Vol 34 (3) ◽

pp. 550C-550

Author(s):

James A. Zwack ◽

William R. Graves ◽

Alden M. Townsend

Keyword(s):

Stomatal Conductance ◽

Root Zone ◽

Numerical Data ◽

Control Treatment ◽

Blue Color ◽

Leaf Color ◽

Similar Reduction ◽

Rooted Cuttings ◽

Potted Plants

We compared two putative Freeman maples [`Jeffersred', (Autumn Blaze ®) and `Indian Summer'] and five red maples [`Franksred' (Red Sunset ®), `Autumn Flame', `PNI 0268' (October Glory®), `Fairview Flame', and unnamed selection 59904] for effects of flooding on stomatal conductance. A method for quantifying changes in leaf color that occurred on flooded plants also was developed. Potted plants grown from rooted cuttings in a greenhouse were subjected to 75 days of root-zone inundation (flood treatment) or were irrigated frequently (control treatment). Across genotypes, stomatal conductance of flooded plants initially increased by about 20% and then fell to and was sustained below 50 mmol·s–1·m–2. Stomatal conductance of flooded plants of `Indian Summer' decreased to 20 mmo·s–1·m–2 after 8 days of inundation, and two of three flooded `Indian Summer' plants died during treatment. Other genotypes required at least twice this time to display a similar reduction in stomatal conductance, indicating `Indian Summer' may be particularly flood sensitive. Intensities of red, green, and blue color at a consistent interveinal position were analyzed with Visilog software by using scanned leaf images of the youngest fully expanded leaf of each plant in both treatments. A genotype × irrigation interaction existed for the ratio of green to red intensity. This method provided numerical data that corresponded well to differences among genotypes we observed visually. For example, while flooding did not alter the color of `Autumn Flame' leaves, the ratio of green to red was three times greater for controls of Autumn Blaze® than for the flooded plants of this cultivar.

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High Root-zone Temperature Causes Similar Changes in Water Relations and Growth of Silver Maples from 33° and 44°N Latitude

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.122.2.195 ◽

1997 ◽

Vol 122 (2) ◽

pp. 195-199 ◽

Cited By ~ 5

Author(s):

William R. Graves ◽

Anthony S. Aiello

Keyword(s):

Stomatal Conductance ◽

Heat Resistance ◽

Surface Area ◽

Leaf Surface ◽

Root Zone ◽

Dry Mass ◽

Root Zone Temperature ◽

Silver Maple ◽

Leaf Surface Area ◽

Zone Temperature

Information on the heat resistance of silver maple (Acer saccharinum L.) could help develop stress-resistant Freeman maples (Acer ×freemanii E. Murray). Our first objective was to determine how 26, 30, 32, 34, and 36 °C in the root zone affect growth and water relations of plants from rooted cuttings of a silver maple clone indigenous to Mississippi (33.3 °N latitude). Fresh mass increased over time for plants at all temperatures and was highest for plants with root zones at 30 °C. Quadratic regression functions predicted maximal plant dry mass, leaf surface area, and stomatal conductance at 29, 29, and 28 °C, respectively. Stem xylem water potential (ψ) during the photoperiod decreased linearly with increasing root-zone temperature from -0.83 MPa at 26 °C to -1.05 MPa at 36 °C. Our second objective was to compare six clones of silver maple from the Mississippi location with six clones from 44.4 °N latitude in Minnesota for effects of 35 °C in the root zone on plant growth, stomatal conductance, and stem ψ. Provenance and temperature main effects were significant for most dependent variables, but there were no provenance × temperature interactions. Over both provenances, plant fresh and dry mass, leaf surface area, stomatal conductance, and stem ψ during the photoperiod were higher at 29 than 35 °C. Over both temperatures, plants from Minnesota clones had higher fresh and dry mass and more leaf surface area than plants from Mississippi clones. The lack of temperature × provenance interactions suggests that ecotypic or clinal variation in heat resistance is minimal and will not be useful for identifying superior genotypes for use in interspecific crosses with red maple (Acer rubrum L.).

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Assessment of tolerance for reducing yield losses in field pea caused by Aphanomyces root rot

Canadian Journal of Plant Science ◽

10.4141/cjps2012-183 ◽

2013 ◽

Vol 93 (3) ◽

pp. 473-482 ◽

Cited By ~ 8

Author(s):

R. L. Conner ◽

K. F. Chang ◽

S. F. Hwang ◽

T. D. Warkentin ◽

K. B. McRae

Keyword(s):

Disease Severity ◽

Root Rot ◽

Weight Ratio ◽

Field Pea ◽

Control Measures ◽

Effective Control ◽

Yield Losses ◽

Plant Vigour ◽

Shoot Weight ◽

High Yields

Conner, R. L., Chang, K. F., Hwang, S. F., Warkentin, T. D. and McRae, K. B. 2013. Assessment of tolerance for reducing yield losses in field pea caused by Aphanomyces root rot. Can. J. Plant Sci. 93: 473–482. Aphanomyces root rot, caused by Aphanomyces euteiches Drechs., is a serious disease of peas (Pisum sativum) that can severely reduce seed yield, and few effective control measures are available. The development of pea cultivars with tolerance or partial resistance to Aphanomyces root rot is generally considered to be one of the best options to reduce yield loss. A 4-yr field study was conducted at disease-free sites and at an Aphanomyces root rot site to compare the responses of cultivars and lines in the presence and absence of Aphanomyces root rot, identify breeding lines with tolerance and to evaluate the effects of tolerance on plant growth, disease severity and yield. At the Aphanomyces root rot site, a second test was established in which the phosphite fungicide Phostrol™ was applied as a soil drench treatment to the pea cultivars and lines. Aphanomyces root rot reduced seedling emergence, biomass production and yield in the susceptible pea genotypes. However, line 00-2067 consistently produced relatively high yields at all the field sites. At the Aphanomyces root rot site, yield was closely associated with plant vigour and shoot weight. Small, but significant, differences (P<0.05) in disease severity were observed between susceptible cultivars and tolerant lines indicating that the lines producing high yields at the Aphanomyces root rot site are tolerant rather than partially resistant. The root/shoot weight ratio was very low in the tolerant lines, indicating that even though their root systems were reduced and severely damaged by root rot, they were still able to produce high yields under favourable conditions for the disease. Drench application of the fungicide Phostrol™ did not significantly reduce root rot severity or improve the performance of any of the pea cultivars or lines.

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Micro-Water Harvesting and Soil Amendment Increase Grain Yields of Barley on a Heavy-Textured Alkaline Sodic Soil in a Rainfed Mediterranean Environment

Agronomy ◽

10.3390/agronomy11040713 ◽

2021 ◽

Vol 11 (4) ◽

pp. 713

Author(s):

Edward G. Barrett-Lennard ◽

Rushna Munir ◽

Dana Mulvany ◽

Laine Williamson ◽

Glen Riethmuller ◽

...

Keyword(s):

Soil Solution ◽

Elemental Sulfur ◽

Root Zone ◽

Soil Surface ◽

Conventional Tillage ◽

Barley Grain ◽

Control Treatment ◽

Water Harvesting ◽

Hordeum Vulgare L ◽

Salt Leaching

This paper focuses on the adverse effects of soil sodicity and alkalinity on the growth of barley (Hordeum vulgare L.) in a rainfed environment in south-western Australia. These conditions cause the accumulation of salt (called ‘transient salinity’) in the root zone, which decreases the solute potential of the soil solution, particularly at the end of the growing season as the soil dries. We hypothesized that two approaches could help overcome this stress: (a) improved micro-water harvesting at the soil surface, which would help maintain soil hydration, decreasing the salinity of the soil solution, and (b) soil amelioration using small amounts of gypsum, elemental sulfur or gypsum plus elemental sulfur, which would ensure greater salt leaching. In our experiments, improved micro-water harvesting was achieved using a tillage technique consisting of exaggerated mounds between furrows and the covering of these mounds with plastic sheeting. The combination of the mounds and the application of a low rate of gypsum in the furrow (50 kg ha−1) increased yields of barley grain by 70% in 2019 and by 57% in 2020, relative to a control treatment with conventional tillage, no plastic sheeting and no amendment. These increases in yield were related to changes in ion concentrations in the soil and to changes in apparent electrical conductivity measured with the EM38.

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Plant Growth Response to the Phytotoxin Viridiol Produced by the FungusGliocladium virens

Weed Science ◽

10.1017/s0043174500075627 ◽

1988 ◽

Vol 36 (5) ◽

pp. 683-687 ◽

Cited By ~ 12

Author(s):

Richard W. Jones ◽

W. Thomas Lanini ◽

Joseph G. Hancock

Keyword(s):

Root Zone ◽

Wide Spectrum ◽

Soil Surface ◽

Application Rate ◽

Herbicidal Activity ◽

Peat Moss ◽

Application Rates ◽

Gliocladium Virens ◽

Root Necrosis ◽

Shoot Weight

Gliocladium virens, when grown on peat moss amended with sucrose and ammonium nitrate and then applied to soil, resulted in root necrosis. Herbicidal activity was correlated with fungal production of the phytotoxin viridiol. Viridiol had a wide spectrum of activity; it was particularly effective against annual composite species but was less effective in monocot control. Emergence of most weeds was reduced >90% at application rates of 8.7% (of total volume) or less. Treated seedling dry weights were drastically reduced. Applications of 4.5% reduced root and shoot weight of redroot pigweed by 93 and 98%, respectively. Crops were affected at higher treatment levels; however, the toxicity was readily avoided by applying the mycoherbicide out of the root zone of the crop, instead applying it between the seed and the soil surface. Viridiol production, which confers herbicidal activity, was detected 3 days after incorporation of the fungus-peat mixture. Viridiol production peaked on days 5 and 6 at approximately 25 μg viridiol/100 ml soil, based upon an application rate of 11%, then declined to undetectable levels by the end of 2 weeks.

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Responses to High Root-zone Temperature Among Cultivars of Red Maple and Freeman Maple

Journal of Environmental Horticulture ◽

10.24266/0738-2898-13.2.82 ◽

1995 ◽

Vol 13 (2) ◽

pp. 82-85

Author(s):

Lorna C. Wilkins ◽

William R. Graves ◽

Alden M. Townsend

Keyword(s):

Root Zone ◽

Acer Rubrum ◽

Dry Mass ◽

Stem Length ◽

Red Maple ◽

Third Order ◽

Root Zone Temperature ◽

Leaf Chlorophyll ◽

Order Root ◽

Zone Temperature

Abstract Two experiments were conducted to determine whether genotypes of red maple (Acer rubrum L.) and Freeman maple (A. x freemanii E. Murray) differ in responses to high root-zone temperature. During the first experiment, dry mass of ‘Franksred’, ‘October Glory’, and ‘Schlesinger’ red maple, ‘Indian Summer’ Freeman maple, and selections from Arkansas, Maine, and Wisconsin were similar at 24, 28, and 32C (75, 82, and 90F), but dry mass at 36C (97F) was only 22% of that at 28C (82F). ‘Autumn Flame’, ‘Franksred’, ‘October Glory’, and ‘Schlesinger’ red maple and ‘Indian Summer’ and ‘Jeffersred’ Freeman maple differed in responses to 34C (93F) during the second experiment. Stem length and plant dry mass were higher at 28C (82F) than at 34C (93F) for all cultivars except ‘Autumn Flame’ and ‘Jeffersred’, and the extent to which 34C (93F) decreased the length of the longest third-order root ranged from 50% for ‘Autumn Flame’ to 90% for ‘Indian Summer’. The higher root-zone temperature decreased transpiration by as little as 25% for ‘Jeffersred’ to as much as 89% for ‘Franksred’, and 34C (93F) reduced leaf chlorophyll content of only ‘Indian Summer’ and ‘Jeffersred’. These results indicate that ‘Franksred’ and ‘Indian Summer’ are relatively sensitive while ‘Autumn Flame’, ‘Jeffersred’, and ‘Schlesinger’ are relatively resistant to high root-zone temperature.

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