ROOT ZONE TEMPERATURE INFLUENCES THE GROWTH, DRY MASS PARTITIONING AND LEAF MORPHOLOGY OF ACTIVELY GROWING AND BUD-BREAK PLANTS OF THE PEACH ROOTSTOCK, GREEN LEAF NEMAGUARD

This paper examines the hypothesis that root zone temperature (RZT) affects the growth of stone fruit plants. This hypothesis was tested by growing plants of the peach rootstock, Green Leaf Nemaguard (Prunus persica L. Batsch), at a diurnally variable (26/15°C) or at constant (5, 15, 20°C) RZTs; the plants were either actively growing or emerging from dormancy when the treatments were applied. These trials demonstrated that RZT, independently of air temperature and light intensity, influences growth, dry matter partitioning, leaf morphology and physiological processes. The growth of plants emerging from dormancy was more sensitive to RZT than that of actively growing plants, therefore, phenology can influence sensitivity to RZT. The area, numbers and daily rates of expansion of leaves, correlated positively with RZT for both sets of plants. However, plants exposed to a diurnally variable 26/15°C RZT were smaller with respect to overall growth and aspects of leaf morphology than plants exposed to a constant 20°C RZT, despite the daily mean RZTs for both treatments being similar. This could be due to supraoptimal RZTs during the day and/or suboptimal RZTs at night. Root mass ratio, in both actively growing and plants exiting dormancy was highest at 20° RZT. In contrast, the stem mass ratio of actively growing plants was maximised at 5°C, and for plants exiting dormancy, the stem mass ratio was minimised at this RZT. RZTs influence the rate of leaf expansion, which in turn affects the total number of leaves and leaf area and, along with its effect on CO2 assimilation rates, results in reductions in DM production. This research illustrates the importance of RZTs, particularly in the spring, on growth and leaf development and suggests the need to incorporate RZT into development models for peaches.

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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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Propagation Daily Light Integral and Root-Zone Temperature Influence Rooting of Single-internode Pennisetum ×advena Culm Cuttings

HortScience ◽

10.21273/hortsci12455-17 ◽

2018 ◽

Vol 53 (2) ◽

pp. 176-182 ◽

Cited By ~ 2

Author(s):

W. Garrett Owen ◽

Roberto G. Lopez

Keyword(s):

Root Zone ◽

Biomass Accumulation ◽

Dry Mass ◽

Naphthaleneacetic Acid ◽

Root Zone Temperature ◽

Daily Light Integral ◽

Pennisetum Setaceum ◽

The Impact ◽

Light Integral ◽

Zone Temperature

Crown division, tissue culture, and culm cuttings are methods for propagating purple fountain grass [Pennisetum ×advena Wipff and Veldkamp (formerly known as Pennisetum setaceum Forsk. Chiov. ‘Rubrum’)]. However, propagation by culm cuttings is becoming an economically attractive method for quick liner production. Our objective was to quantify the impact of propagation daily light integral (PDLI) and root-zone temperature (RZT) on root and culm development of single-internode purple fountain grass culm cuttings. Before insertion into the rooting substrate, cuttings were treated with a basal rooting hormone solution containing 1000 mg·L−1 indole-3-butyric acid (IBA) + 500 mg·L−1 1-naphthaleneacetic acid (NAA). The cuttings were placed in a glass-glazed greenhouse with an air temperature of 23 °C and benches with RZT set points of 21, 23, 25, or 27 °C. PDLIs of 4 and 10 mol·m−2·d−1 (Expt. 1) or 8 and 16 mol·m−2·d−1 (Expt. 2) were provided. After 28 d, culm and root densities (number) increased as the RZT increased from 21 to 27 °C, regardless of PDLI during Expt. 1. Compared with 4 mol·m−2·d−1, a PDLI of 10 mol·m−2·d−1 generally resulted in the greatest root biomass accumulation. For example, as PDLI increased from 4 to 10 mol·m−2·d−1, root dry mass increased by 105%, 152%, and 183% at RZTs of 21, 25, and 27 °C, respectively. In Expt. 2, as the RZT increased from 21 to 23 °C, root dry mass increased by 70% under a PDLI of 8 mol·m−2·d−1. However, root dry mass was similar among all RZTs under a PDLI of 16 mol·m−2·d−1. Our results indicate that single-internode culm cuttings of purple fountain grass can be most efficiently propagated under PDLIs of 8–10 mol·m−2·d−1 together with RZT set points of 23 to 25 °C for quick liner production.

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Supplementary Irrigation and Mulch Benefit the Establishment of `Heritage' Primocane-fruiting Raspberry

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.123.4.518 ◽

1998 ◽

Vol 123 (4) ◽

pp. 518-523 ◽

Cited By ~ 1

Author(s):

David C. Percival ◽

J.T.A. Proctor ◽

J.A. Sullivan

Keyword(s):

Field Experiments ◽

Root Zone ◽

Carbon Assimilation ◽

Nutrient Content ◽

Dry Mass ◽

Rubus Idaeus ◽

Trickle Irrigation ◽

Root Zone Temperature ◽

Supplementary Irrigation ◽

Zone Temperature

Field experiments including supplementary trickle irrigation (IR), IRT-76 plastic film (PF), and straw mulch (STR) treatments were conducted during 1993 and 1994 to determine the influence of root-zone temperature and soil moisture status on carbon assimilation and dry mass distribution, and soil and plant nutrient content, during the establishment of Rubus idaeus L. `Heritage' primocane-fruiting raspberries. The IR, PF, and STR treatments were reapplied after the 1993 establishment year to examine their effects on an established, hedgerow planting. Physical environment, vegetative and reproductive data were collected. PF increased root and shoot mass, total flower number, and total berries harvested. Maximum leaf net photosynthetic (Pn) rates were observed under cool air temperatures and root-zone temperature of 25 °C. Field Pn measurements indicated that there was no seasonal decline in Pn. Mulch treatments however, were not beneficial to the established (i.e., 2-year-old) hedgerow planting. The root system of the 2-year-old planting was largely confined to an area within the foliage wall and also at a greater depth from the mulch treatments. Therefore, beneficial effects of mulch management on the growth and development of raspberries may be limited to the establishment year.

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Physiology and metabolism of grafted bell pepper in response to low root-zone temperature

Functional Plant Biology ◽

10.1071/fp18206 ◽

2019 ◽

Vol 46 (4) ◽

pp. 339 ◽

Cited By ~ 3

Author(s):

Moses Kwame Aidoo ◽

Tal Sherman ◽

Naftali Lazarovitch ◽

Aaron Fait ◽

Shimon Rachmilevitch

Keyword(s):

Gas Exchange ◽

Low Temperature ◽

Root Zone ◽

Dry Mass ◽

Bell Pepper ◽

Gas Chromatography Mass Spectrometry ◽

Limiting Factor ◽

Root Zone Temperature ◽

Low Root Zone Temperature ◽

Zone Temperature

Low temperature is a prominent limiting factor for tropical originated crops production in temperate regions, particularly during cool-season production. The diverse response of two rootstocks (Canon-sensitive and S103-tolerant to low root-zone temperature) was studied when exposed to aeroponically different temperature regimes at the root zone: constant low temperature of 14°C low root-zone temperature (LRZT), transient exposure to LRZT of 27–14−27°C and control temperature of 27°C. Gas exchange, shoot dry mass, and root morphology were measured. Shifts in central and secondary metabolite levels in the leaves and roots were examined by gas chromatography-mass spectrometry (GC-MS). Low root-zone temperature inhibited photosynthesis and transpiration of both grafted bell pepper plants; however, self-grafted Canon physiology was impeded to a greater extent compared with Canon grafted onto rootstock S103. Rootstock S103 demonstrated higher sink potential contributing to milder reduction of photosynthesis and transpiration during stress compared with self-grafted Canon. This reduction of gas exchange led to a significant reduction of root maximum length and root dry mass in self-grafted Canon in response to the stress at 14°C compared with Canon grafted onto rootstock S103. In response to stress, GC-MS metabolite profiling showed enhance metabolism in both cultivars’ leaves, as well as in the roots irrespective of the developmental stage of the plant. This evidence combined indicates enhance gas exchange and carbon assimilation when bell pepper is grafted on S103 under low root-zone temperature.

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196 EFFECTS OF DROUGHT AND ROOT-ZONE TEMPERATURE ON GROWTH AND WATER RELATIONS OF SILVER MAPLES FROM FIVE PROVENANCES

HortScience ◽

10.21273/hortsci.29.5.457c ◽

1994 ◽

Vol 29 (5) ◽

pp. 457c-457

Author(s):

Anthony S. Aiello ◽

William R. Graves ◽

John E. Preece

Keyword(s):

Root Zone ◽

Dry Mass ◽

Annual Rainfall ◽

Root Zone Temperature ◽

Silver Maple ◽

Experiment Control ◽

Leaf Surface Area ◽

Effects Of Drought ◽

Initial Results ◽

Zone Temperature

Along with its horticultural uses, silver maple (Acer saccharinum L.) can be grown for biomass in areas that vary greatly in annual rainfall and temperature. Silver maples from five provenances ranging from 33 to 46° N latitude were subjected to drought stress and to high root-zone temperature (RZT) in separate experiments to assess their suitability as biomass sources. In the drought experiment, control plants were irrigated every 2 days, while stressed plants were irrigated every 15 days. Initial results indicated provenance differences among control plants in dry mass, leaf area, and transpiration. Drought reduced growth and mitigated differences among provenances. Osmotic potential of leaves was higher in control plants than in drought-stressed plants. Plants from two provenances (33 and 44° N) were grown with RZT of 24 and 34 C for 3 weeks. Gain in fresh mass over time was reduced at 34 C for plants of both origins, but plant dry matter and leaf surface area were similar at the two RZT. Data collected to date suggest resistance to drought and high RZT is similar in plants of different provenances.

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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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326 High Root-zone Temperature Inhibits Strawberry Reproductive and Vegetative Growth and Development

HortScience ◽

10.21273/hortsci.34.3.499b ◽

1999 ◽

Vol 34 (3) ◽

pp. 499B-499

Author(s):

Melita Marion Biela ◽

Gail R. Nonnecke ◽

William R. Graves ◽

Harry T. Horner

Keyword(s):

Leaf Area ◽

Vegetative Growth ◽

Growth And Development ◽

Root Zone ◽

Block Design ◽

Dry Mass ◽

Fruit Production ◽

Root Zone Temperature ◽

Leaf Dry Mass ◽

Zone Temperature

High temperatures are reported to promote day-neutral strawberry (Fragaria ×ananassa) vegetative growth and development and inhibit floral and fruit development, thereby imposing geographic and temporal limitations on fruit production. Day-neutral strawberry response to air temperature has been researched, but specific responses to temperature in the root zone have not. In a 1998 greenhouse experiment, 60 `Tristar' plants were grown hydroponically in a system of individual, temperature-controlled pots. A randomized complete-block design with constant root-zone treatments of 11, 17, 23, 29, and 35 °C and 12 replications were used. Stomatal conductance and transpiration rate were significantly lower for plants at 35 °C, compared with plants at all other temperatures. Leaf area and leaf dry mass of plants at 35 °C were five and four times smaller, respectively, than the combined mean for plants in all other treatments. Leaf area of runner tips was 450 and 44.5 cm2 at 11 and 35 °C, respectively, compared with that of plants at all other temperatures, 1552.1 cm2. Fruit dry mass was 14.5, 21.6, 25.5, 29.0, and 3.96 g per plant at 11, 17, 23, 29, and 35 °C, respectively. Root dry mass was highest at 11 and 17 °C and lowest for plants at 35 °C. The number of flowers, fruit, and inflorescences per plant was reduced at 35 °C, as were individual berry fresh mass and diameter. Overall, `Tristar' growth and development were near optimal at 17, 23, and 29 °C.

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Root-zone Temperature Effects Onion Content of Tomato, Muskmelon, and Honey Locust

HortScience ◽

10.21273/hortsci.30.4.789a ◽

1995 ◽

Vol 30 (4) ◽

pp. 789A-789

Author(s):

Kimberly A. Klock ◽

Henry G. Taber ◽

William R. Graves

Keyword(s):

Root Zone ◽

Mass Gain ◽

Dry Mass ◽

Root Zone Temperature ◽

P Content ◽

Total Plant ◽

Mn Content ◽

Honey Locust ◽

Gold Star ◽

Zone Temperature

Horticultural species vary in growth response to high root-zone temperature (RZT), but little is known about the effects of RZT on nutrient uptake. We determined P, K, Ca, Mg, Zn, and Mn total plant content of tomato (Lycopersicon esculentum Mill. cv. Jet Star), muskmelon (Cucumis melo L. cv. Gold Star), and honey locust (Gleditsia triacanthos L. var. inermis Willd.) grown in nutrient solution kept at 24, 27, 30, 33, and 36C. RZT effects on plant dry mass gain and gain in nutrient per plant varied by species. Honey locust and tomato total plant gain in P decreased linearly with increasing RZT, while melon P content increased linearly to 36C. Trends in total Mg and Mn content will be presented, as well as results from further research on correlations between supraoptimal RZT, root respiration, and shoot and root P content of tomato.

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