Red Sunset Research Articles

Intersectional Hybrids between Darrow's Blueberry (V. darrowii Camp) and Lingonberry (V. vitis-idaea L.).

An initial cross of V. darrowii 'Johnblue' (Darrow's blueberry) × V. vitis-idaea 'Red Sunset' (lingonberry) produced more than 30 true intersectional diploid hybrids as confirmed by molecular markers. The most vigorous of these hybrids was extensively evaluated. This hybrid, US 2535-A, was floriferous and morphologically intermediate to the respective parents. Examination of pollen suggested low male fertility. Numerous crosses using the hybrid as a female reflected similarly low fertility and potential crossing barriers. Stylar examination suggested blockage of pollen tube growth in self-pollinations and significantly retarded growth in backcross pollinations. Nonetheless, two confirmed hybrid offspring were produced using the F1 hybrid as a female in crosses with V. vitis-idaea and V. darrowii, respectively. In a second set of crosses utilizing additional V. darrowii and V. vitis-idaea genotypes, another 23 verified hybrids in seven parental combinations were produced. Hybrids such as the ones presented offer the potential for generating de novo interspecific fruit types in blueberry and/or broadening the adaptation of lingonberry.

"Are You Trembling, Earth?": Nonhuman Nature in Literary Representations of the Holocaust

Abstract: Applying an ecocritical lens to Holocaust literature, this paper explores the connection between the natural world and the seemingly unnatural machinations of the Holocaust by placing two writers in conversation: Abraham Sutzkever and Vasily Grossman. For Sutzkever, the famed Yiddish poet of Vilna, poetry was linked to survival and to the environment, sometimes emerging from a bog, wilderness, or mutilated landscape but shining all the more brightly for its mired origins. Grossman, another important documenter of the Holocaust, was a Soviet-Jewish writer known for his reportage, fiction, and compilations of Jewish documents from the Second World War. Like Sutzkever, Grossman was occupied in his work with the earth and its animate and inanimate inhabitants, from the crying stones and soil of Treblinka to the red sunset of a humanity ravaged by genocide. When faced with the almost unnarratable desolation and loss encountered during the Holocaust, both authors turned to their environment as a literary tool, a means of conveying that which could not be conveyed through traditional or accepted language. Nature and the nonhuman world became vehicles for an exploration of trauma and violence that in many ways extended beyond human comprehension, and therefore required a mode of imagining that similarly extended beyond human experience alone. At the same time, both Sutzkever and Grossman can be seen attempting to allow nonhuman nature to speak in its own voice, however inflected by human perspectives the hearing and translation of that voice may be. This paper therefore reveals and highlights the importance of addressing the interactions between human and nonhuman nature in Holocaust literature.

Control of Insects and Diseases with Intelligent Variable-rate Sprayers in Ornamental Nurseries

Abstract Intelligent spray technology can reduce pesticide use and safeguard the environment; however, its ability to effectively control insects and disease must be validated before its adoption by growers. Comparative tests for two different laser-guided variable-rate intelligent sprayers and the same sprayers with conventional constant-rate mode were conducted to control pests at two ornamental nurseries in two growing seasons in Ohio. Crabapple [Malus ‘Sutyzam’ (Sugar Tyme®), M. sargentii], apple (Malus pumila), maple [Acer ×freemanii ‘Jeffersred' (Autumn Blaze®), A. rubrum ‘Franksred' (Red Sunset®) and A. rubrum], birch (Betula nigra and Betula populifolia ‘Whitespire'), London planetree (Platanus ×acerifolia ‘Bloodgood') and dogwood (Cornus florida) were used as the test plants. Intelligent spray technology reduced pesticide use by 56.1% and 51.8% on average at the two nurseries, respectively. Compared to conventional air-assisted sprayers, severity of scab on apple trees and powdery mildew in dogwood was reduced on intelligent spray-treated plants at one nursery, and there were equal or fewer leafhoppers in maple trees and aphids in birch trees when sprayed using intelligent spray technology at both nurseries. These results suggest that intelligent, variable-rate sprayers achieve equivalent or greater insect and disease control in ornamental tree nurseries compared to conventional, constant-rate sprayers. Index words: aphid, apple scab, environmental protection, leafhopper, precision spray, powdery mildew, sustainable. Species used in this study: apple (Malus pumila Mill), birches (Betula nigra L, Betula populifolia Marsh. ‘Whitespire'), crabapples [Malus ‘Sutyzam' (Sugar Tyme®), M. sargentii Rehder], dogwood (Cornus florida L.), maples [Acer ×freemanii E. Murray ‘Jeffersred' (Autumn Blaze®), A. rubrum L. ‘Franksred'(Red Sunset®) and A. rubrum L.], London planetree [Platanus ×acerifolia (Ait.) Willd. ‘Bloodgood'].

After the War

After the War DAVID GOMES CÁSSERES invocation: athena for PLP Grey-eyed Athena had no childhood. She stepped out of the old god’s terrible skull a grown young goddess and began her apprenticeship: running sex-driven cults among the hunters and gatherers, collecting snakes and owls, her aegis looming behind the altars, over her priestesses, prophetic crones and breathless temple prostitutes, sacrificed animals bleeding and burnt ears of grain She gained a reputation: she liked clever men, not that way, no, but she did them favors, paid attention to their deeds and needs and risks and wounds and wants. Her admiration was something a clever man could count on; she would give protection, opportunities, good luck. There was a catch, of course: you had to be clever again, you had to keep impressing the grey-eyed one, and so men lasted a while but couldn’t keep it up, and fell, and well, she forgot them. She was busy. But Odysseus: He was another kind. One stratagem after another, he built up so much credit that she saved him even when he disgraced himself one time or another. (Olympus might have disapproved if they’d noticed, but she had walked far away from that rabble of archetypes, totems, fertilities, boogeymen and witch-mothers, nightwalkers, netherdwellers, sexpots and satyrs. She owned her firmament.) Odysseus was something new to her in his little flick of mortality. So when she stood alone in Penelope’s bedchamber watching the reunion, the circling dance of man and woman arion 27.2 fall 2019 step by step negotiating what they knew after so many years their carefulness like oil on water, leveling out the fresh reek of murder from the great hall below them the suitors’ teeth driven into the earthen floor Odysseus striped with their blood Penelope before her loom, many-stringed weapon of her own warfare weaving each other in that long rite of recognition: Her grey eyes saw words forming and fading unsaid As they circled in the salt red sunset Ionian air. And saw the end of her story with Odysseus; goddess and all, it took away her breath. In the end she had this much to show for her years with this clever man: He came home from the war alive, with all his teeth. 2 after the war First published as “Athena,” in Arion 21.3, Winter 2014 telemachus 1. It’s like this. I come to manhood at fourteen and my life’s just misery and shame. There’s no King in Ithaka and my mother, the Queen, is like a prisoner. All our warriors are scattered in the sea somewhere by Athena’s great storm. Our home, the palace of godlike Odysseus, is full of parasites and pirates, We live there paralyzed, taunted by those swarming men and the people who cling to them, even some of my mother’s maids, girls my age or a little older— nasty girls who know all the ways to mock and mortify a boy squirming into manhood without a father. Of course I run away, of course I go looking for wily Odysseus, the King, my father. I never find him, it’s for him to find me, later. But I did learn to tie seamen’s knots, and I have a traveler’s tale: One night I was at the house of Menelaus and Helen, drinking good wine late into the night. They sent the servants to bed, and the three of us sat in the red light of the dying fire. Menelaus, still handsome with some grey in his red hair, spoke of my father Odysseus: “Do you know what he said? He said to me, we are better than the gods; we are kings. And kings must die, as the gods cannot. He said it to me when we were striding with our swords in hand through the broken gates of Troy, and as calmly as he might say it to you.” As he spoke, Menelaus of the great war-cry was fondling the arm of his wife, Helen, for whose beauty all that blood was shed. I was sitting with the people the poets sing...

Letter from Eudora Welty to Elizabeth Bowen, August 1951

Letter from Eudora Welty to Elizabeth Bowen, August 1951 Eudora Welty New Orleans, August 17 [1951]1 Dearest Elizabeth, November 26th you'll be here! I just called Tulane University and wrote it down—just when you were South before. We shall have Thanksgiving. I'll meet you here. Is everything working out all right? Please don't let dates and dates come up and crowd out your time this way—I know people will be asking you the same thing all around—and don't give up of course one thing you want to do anywhere, or one place you want to see, but I hope so very much you'll keep as much time as you possibly can free for us to meet. I only wish the time were nearer. It's so hot now—but it will be all right I hope by the time you come. Do you think at the end of the lectures you could come for a real visit? Some weeks? Day before yesterday (what I'm doing here: came to an air-conditioned hotel to do work on a story, high & mighty of me) I went to Venice, La.—the last stop, end of the road, down the Mississippi—it was a strange world too. A sultry, hot (99) day, we went lower than the river, beside2 the levee—(I was with a young Harvard professor, Carvel Collins,3 who turns out to work under your friend Dr. Murdoch4—he came through) and crossed the river on a good ferry at Pointe a la Hatche, full of Cajuns combing their hair and giving each other baskets of shrimp [what coals to Newcastle!]5—we went into a remarkable cemetery that (but you must see it just like this) was two rows of elevated graves, like bureau drawers, with the fronts newly whitewashed, the cartracks paved between—car almost touched as we drove—6 straight down this alley to the church, green and white frame with poinsettias planted around it—and beyond the church was the priest's house with his cassock hung out on the clothesline to air—all in an enormous red sunset light—the white and black and the vivid green, and the raging sound of all those crickets and locusts and what-all in the jungle around it. Crawfish scuttled across the road in front of us—Big okra patches high as your head and white as snow from7 dust—lots of little fishing boats right at any break in the forest—the water. The towns began with Arabi—and there was Port Sulfur, Jesuit Bend, Naomi, [End Page 5] Alliance, Junior, Diamond, Socola, Happy Jack, Empire (a bad smell there, burning old fish?), Buroa,8 Triumph, Concession, Phoenix, Nero, Ostrica and Venice. I don't mean we found all those—where were they? But they were on the map—maybe taking in both sides of the river. I wished for you. Except the mosquitoes were so thick, everyone on the road carried a branch of a palm to keep flailing around—this worried my Massachusetts friend all night, he said, poor thing, all that malaria—it is a dreadful thought. Every time I saw a little house I wanted—one of those like I always do—he said, But the mosquitos. Huge sky, and the biggest moon came up—and after dark, the dust was like lakes all around us, with fires burning in their centers, and around the fires, cows—all untended—standing in a ring—in the heat and the night, to keep off mosquitos—away off in the marshes, you could see their horns standing up black against that lonely glow. Life is very gay in the villages—movies ("Rocket-Ship X-M"), Booga Red's Place, Te-Ta's Place, Paradise—cards and you could tell it was a dance floor too—slot machines. Juke boxes lit up. Full of children. They were going to have a Shrimp Dance the next night—I longed to return. Huge catfishes were lying on people's front porches. The whole place was amphibious—The people were dark, merry, with white teeth, teasing—one...

Growth and stability of deep planted red maple and northern red oak trees and the efficacy of root collar excavations

Trees with root systems established well below grade due to deep planting or soil disturbance are common in urban landscapes, yet the long term effects of buried trunks and subsequent remediation strategies, such as root collar excavation are poorly documented. We evaluated the consequences of deep planting over a 10-year period on tree growth and stability, with and without root collar excavation, for red maple [Acer rubrum L. Red Sunset® (‘Franksred’)] and Northern red oak (Quercus rubra L.) planted at grade or 30-cm below grade. Sleeves to prevent soil-trunk contact were installed around trunks on a subset of deep trees. Root collar excavations were made during the 6th growing season for both species and trees were grown for an additional 4 and 3 growing seasons for red maples and Northern red oaks, respectively. Within two weeks of root collar excavations, pulling tests compared the effect of treatments on stability of red maples. Deep planting generally slowed growth of red maple but had no clear effect on Northern red oak. Root collar excavation had no lasting effect on growth of either species. Approximately 55% of deep red maples and 33% of deep Northern red oaks had roots crossing and in intimate contact with buried trunks, suggesting a potential for future girdling roots. Approximately 25% of deep maples had substantial adventitious rooting. All deep Northern red oaks had new roots emerging just above the first original structural roots but none were clearly adventitious. Trunk sleeves had no effect on growth for either species. Neither deep planting nor root collar excavation resulted in a loss of tree stability compared to trees planted at grade, although failure patterns varied among treatments. Overall, the biggest long term concern for deep-planted trees is the potential for girdling root formation.

Red Sunrise, Blue Sky, and Red Sunset: the Light Refraction of Earth Atmosphere

The red sunrise, red sunset, and blue sky were common nature phenomena. Why sunrise and sunset are red color, and why daytime sky is blue? This paper used earth atmosphere refraction principles to explain the sky and sun color. The “energy attract force equation” was considered to explain the sun light offset at the outer atmosphere acted by earth mass, which may be better for understand the Relativity Theory. The conclusion will be benefit for the telescope application, satellites communication, astronomy observation, and other atmosphere optical applications.Â

Do leaf domatia mediate intraguild predation and host plant resistance to Oligonychus aceris (Shimer) on Red Sunset Maple (Acer rubrum)?

The predatory mites Neoseiulus fallacis (Garman) (Acarina: Phytoseiidae) and Zetzellia mali (Ewing) (Acarina: Stigmaeidae) have the potential to suppress populations of Oligonychus aceris (Shimer) (Acarina: Tetranychidae) on maple cultivars under field conditions. Red Sunset red maples (Acer rubrum) are more resistant to O. aceris than ‘Autumn Blaze’ Freeman maple (Acer×fremanii). Examination of leaves indicated that the mite resistant Red Sunset trees had more leaf domatia than those from Autumn Blaze. Laboratory assays found that maple cultivars did not affect rates of O. aceris consumption by N. fallacis or Z. mali in a 24h period. Each predator exhibited distinct preferences for O. aceris life stages. N. fallacis consumed significantly more protonymphs and adults of O. aceris, whereas Z. mali consumed more eggs. In contrast, maple cultivars significantly influenced rates of intraguild predation between phytoseiids and stigmaeids. Adult N. fallacis consumed more immature stages of Z. mali on Autumn Blaze than on Red Sunset maple, but adult Z. mali consumed the same numbers of N. fallacis nymphs on both cultivars. These findings provide a potential mechanism to explain the resistance of Red Sunset maples to O. aceris. On Red Sunset maples, where domatia provide Z. mali with refugia from predation by N. fallacis, both predators can contribute to the mortality of O. aceris. In contrast on Autumn Blaze maples Z. mali have no place to hide from N. fallacis, so the contribution of this stigmaeid to O. aceris mortality is greatly diminished. Thus, differential susceptibility of these cultivars to spider mites may be mediated by the capacity of leaf domatia to influence rates of intraguild predation among phytoseiid and stigmaeid predators.

Nutrient Leaching from Container-Grown Ornamental Tree Production

Economical production of marketable container-grown ornamental shade trees with minimum amounts of nutrients in leachate requires careful management of fertilizer applications during a growing season. Sixteen fertilizer treatments were evaluated for their nutrient leaching potential in container-grown ‘Red Sunset’ red maple (Acer rubrum L.) production in a commercial nursery. Tests were conducted at two sites that were irrigated with either city or recycled pond water. Two slow-release granular fertilizers (18-5-12 and 12-0-42) were applied separately or together, by incorporation, top-dressed, or both, to trees grown in #7 containers and placed above or below ground. Trees irrigated with pond water also received supplemental liquid nutrients throughout the growing season along with nitric and phosphoric acids. Compared to either top-dressed or incorporation of fertilizer, incorporation of fertilizer combined with top-dressing doubled the amounts of nutrients applied but did not increase tree growth and caused greater nutrient leaching through the container substrate. Adding nitric and phosphoric acids to the supplemental liquid nutrients had little effect on lowering pH of the container substrate to the desired level. Trees irrigated with pond water had greater caliper growth than trees irrigated with city water, but this practice caused greater nutrient loss through the leachate and required additional nutrient inputs and labor throughout the growing season. Among the 16 fertilizer practices, the top-dressed fertilizer applications in the above- and below-ground containers were the most efficient method to produce fast tree growth with low nutrient leaching.

Effects of Nitrogen Fertilization on Potato Leafhopper (Hemiptera: Cicadellidae) and Maple Spider Mite (Acari: Tetranychidae) on Nursery-Grown Maples.

Although leaf nitrogen (N) has been shown to increase the suitability of hosts to herbivorous arthropods, the responses of these pests to N fertilization on susceptible and resistant host plants are not well characterized. This study determined how different rates of N fertilization affected injury caused by the potato leafhopper (Empoasca fabae Harris) and the abundance of maple spider mite (Oligonychus aceris (Shimer)) on 'Red Sunset' red maple (Acer rubrum) and 'Autumn Blaze' Freeman maple (Acer×freemanii) during two years in Indiana. N fertilization increased leaf N concentration in both maple cultivars, albeit to a lesser extent during the second year of the study. Overall, Red Sunset maples were more susceptible to E. fabae injury than Autumn Blaze, whereas Autumn Blaze maples supported higher populations of O. aceris. Differences in populations of O. aceris were attributed to differences between communities of stigmaeid and phytoseiid mites on each cultivar. Injury caused by E. fabae increased with N fertilization in a dose-dependent manner in both cultivars. Although N fertilization increased the abundance of O. aceris on both maple cultivars, there was no difference between the 20 and 40 g rates. We suggest the capacity of N fertilization to increase O. aceris on maples could be limited at higher trophic levels by the community of predatory mites.

Effects of pesticide application on arthropod pests of nursery-grown maples.

Insecticides used against potato leafhopper, Empoasca fabae (Harris) (Homoptera: Cicadellidae), have been reported to cause problems with maple spider mite, Oligonychus aceris (Shimer) (Acarina: Tetranychidae), on nursery-grown 'Red Sunset' red maple and 'Autumn Blaze' Freeman maple. To test this, we conducted two experiments on field-grown trees in nurseries. In the first, the effects of early-season pesticide applications were examined during 2009. The second experiment was conducted in 2010 to compare effects of using threshold levels of one, three, or six leafhoppers per branch to time applications. Pesticide applications reduced abundance and damage by leafhoppers in both cultivars, but increased populations of O. aceris on Autumn Blaze during 2009. In contrast, on Red Sunset, populations of O. aceris did not increase after insecticide applications. In 2010, insecticide applications did not increase abundance of O. aceris on Autumn Blaze because use of treatment thresholds to manage leafhoppers greatly reduced numbers of trees requiring treatment for leafhoppers. Two phytoseiid mites, Neoseiulus fallacis (Garman) and Typhlodromus caudiglans (Schuster), and one stigmaeid, Zetzellia mali (Ewing), were identified as the principal predators of O. aceris on maple leaves. Insecticide applications had no significant effects on the total abundance of predatory mites on either Red Sunset or Autumn Blaze maples in 2009 or 2010. However, populations of predator Z. mali were higher during both years on Red Sunset than on Autumn Blaze. These results suggest that both early-season pesticide use and cultivar can affect the likelihood of secondary outbreaks of spider mites on maples.

Fertilizer Applications for Container-Grown Ornamental Tree Production

Better management of nutrient applications during a growing season is needed to economically produce marketable container-grown ornamental shade trees. Fertilizer practices were used to test the growth of Acer rubrum ‘Red Sunset’ trees in two commercial nursery fields (each containing four plots) that were irrigated with either city or pond water. In each field, the same 16 treatments were replicated. Two slow-release granular fertilizers (18-5-12 and 12-0-42) were applied separately or together by incorporation, topdress or both to a potting mix for trees grown in 26 liter (7 gal) containers and placed above or below ground. Trees irrigated with pond water also received supplemental liquid nutrients throughout the growing season along with nitric acid to lower the pH of the potting substrate. Tree growth was assessed by stem diameter (caliper), height, canopy size, leaf color and root measurements. Significant higher caliper increases occurred in trees treated with 18-5-12 fertilizer and irrigated with either pond or city water than trees treated with the 12-0-42 fertilizer. Significantly higher percent increases in caliper also occurred for trees irrigated with pond water and top-dressed with 18-5-12 fertilizer than trees with incorporated 18-5-12 fertilizer. With the same slow-release fertilizer applications, trees irrigated with pond water and supplemental nutrients had greater percent increases of caliper, larger canopy areas and better root systems than trees irrigated with city water. The differences in tree height increase were not as great as the caliper increases. However, tree growth irrigated with pond water required additional inputs with extra nutrients and labor costs throughout the growing season.

Extraction and Recognition of Color Feature in true Color Images Using Neural Network Based on Colored Histogram Technique

In this research, a neural network using backpropagation (BPNN) algorithm was trained and learned to work as the cone cells in human eyes to recognize the three fundamental cells’ colors and hues, as the neural network showed good results in training and testing the color feature it was trained and learned again to recognize two nature scenes images ; Red sunset and Blue sky images where both scenes images contain color interaction and different hues such as red-orange and blue-violet. The recognition process was based on color histogram technique in colored images which is a representation of the distribution of colors in an image by counting the number of pixels that have colors in each of a fixed list of color ranges, that span the image's color space , all possible colors in the image. The importance of this research is based on developing the ability of (BPNN) in images ‘objects recognition based on color feature that is very important feature in artificial intelligence and colored image processing fields from developing the systems of alarms robots in fire recognition , medical digenesis of tumors, certain pattern’s recognition in different segments of an image , face and eyes’ iris recognition as a part of security systems , it helps solve the problem of limitation of recognition process in neural networks in many fields.

Cyclanilide Differentially Affects Branching in Red Maple Cultivars and Hybrids

Abstract Development of the canopy is an important aspect of ornamental shade tree production. Branching can be induced by pruning the apical meristem, but this process is time consuming and costly to growers. Cyclanilide is an auxin transport inhibitor that has been successfully used to eliminate apical dominance and increase branching in a number of tree species. In this study, we tested the effects of cyclanilide application in two years on branching, canopy form, and trunk diameter. Cyclanilide did not cause phytotoxicity symptoms in any cultivar at any rate. Two cultivars, Celebration® (Acer × freemanii A.E. Murray ‘Celzam’) and Sienna Glen® (Acer × freemanii ‘Sienna’) Freeman maples responded to cyclanilide treatments with increased primary and secondary shoots, whereas Red Sunset® red maple (Acer rubrum L. ‘Franksred’) and Autumn Blaze® Freeman maple (Acer × freemanii A.E. Murray ‘Jeffersred’) did not respond to any treatments. Responsive cultivars had approximately double the number of growing points and larger total branch length after second year applications, but this did not result in an increase in trunk caliper. Despite the increased number of shoots produced, overall canopy ratings did not differ among treatments. Cyclanilide had a limited affect on branching in red and Freeman maple whips. Furthermore, if growers choose to utilize this product, they should be aware that cultivar response is likely to vary, and initial testing should be done before making large-scale applications.

COMPARISON OF IRRIGATION, LEACHATE AND TREE GROWTH BETWEEN SOILLESS AND COAL ASH BASED MEDIA

In nursery production, knowledge of water quality and quantity is needed to improve irrigation and fertilizer application efficiency as it relates to potential for soil and groundwater contamination. Water and fertilizer use and loss as well as tree growth were investigated for Red Sunset maple (Acer rubrum 'Franksred') trees in a pot-in-pot system with two different potting media and one coal ash based medium. The coal ash based medium (Mix #1) was mainly composed of biosolids, flue gas desulfurization gypsum, and coal combustion bottom ash. The two potting media mainly composed of aged pine bark and steamed composted nursery trimmings as well as left-over potting medium from commercial nurseries, but one with low initial amendments (Mix #2) and the other one with high initial amendments (Mix #3). Trickle irrigation was applied to each tree with an automatic control system. Watering trees started when the medium moisture was below 30%, and stopped when the moisture was 42%. During two-year tests, the amount of water including irrigation and rainfall applied to each tree with Mix #1, #2 and #3 was 741, 910 and 950 L, respectively. The amount of water loss through drainage for each tree with Mix #1, #2 and #3 was 107, 147 and 112 L, respectively. Among the tree media, Medium #3 produced the highest tree growth rate, followed by the Mix #2. The coal ash based medium had great potentials to be used for nursery production.

Impacts of Handling and Transport on the Growth and Survival of Balled-and-burlapped Trees

Transplanted trees are exposed to numerous stresses from the time of harvest until establishment in the landscape. Although an individual stress factor may be the sole cause of plant death or decline, it is more likely a combination of stress factors cause reduced growth or death after planting. In an effort to isolate the stresses associated with three critical stages in the transplanting process (i.e., initial harvest, handling, and transport), 5-cm-caliper, balled-and-burlapped Acer rubrum L. ‘Red Sunset’ (red maple) and Acer platanoides L. ‘Pond’ (Norway maple) trees at three sites (Urbana, IL; Union, IL; and Manitowoc, WI) were subjected to three treatments: root-pruned, handled, and transported. Effects of water stress, root severance, and root-ball disruption on twig elongation and tree survival were measured for each treatment and compared with unaltered control trees. Twig elongation was greater in unaltered control trees when compared with root-pruned trees. In addition, root-pruned trees exhibited greater twig elongation when compared with either handled or transported trees suggesting that although initial root severance did affect growth, it was not as detrimental as lifting and handling. In addition, twig elongation was not different between handled and transported trees. Water potential measurements ranged from –0.2 to –2.0 MPa, suggesting water stress was not a critical factor during the time of transplanting. Similarly, root-ball soil moisture varied little between treatments over the course of transplanting. Results suggest rough handling before and after transport should be minimized in an effort to maximize growth and transplant success.

Dynamic Modeling of Tension-Controlled Irrigation of Container-Grown Nursery Plants

A mathematical model of a closed-loop feedback control system for controlling microirrigation of container-grown nursery plants was developed and tested. Moisture tension in the container medium was the control variable. The system's characteristic transfer function parameters included a time delay (infiltration time), on-off control (irrigation pump), pumping rate, mass of potting medium, moisture tension as a function of potting medium moisture, and a tensiometer response function. Calibration and validation of the model was done using experimental data collected for Red Sunset red maple (Acer rubrum 'Red Sunset') during late summer of 1997. A time-varying, vapor pressure deficit/evapotranspiration transfer function, ETVPD, was used to estimate the plant's rate of removal of water from the root medium (R2 = 0.684). The transfer function underestimated total irrigation water by 25% and overestimated irrigation frequency by 37.5% (11 vs. 8 cycles) during the 14-day experimental validation period. Major differences between experimental validation and simulated results were attributed to the accuracy of the ETVPD model and the use of zero infiltration time (tDT). Key factors identified as directly affecting stability and accuracy of tensiometer-controlled irrigation, in addition to the identified system's parameters, were size of the plant root system and placement of the tensiometer(s). Results showed that only 18% of the total soil medium mass was affecting the systems response function based on the experimental setup of one tensiometer in the potting medium.

(141) Leaf Abscisic Acid Accumulation in Response to Substrate Water Content: Variation Among Acer rubrum L. Genotypes

Quantitative differences in leaf abscisic acid (ABAL) among four cultivars of red (Acer rubrum L.) and one Freeman maple (Acer × freemanii E. Murray) were investigated. This study tested the hypothesis that ABAL concentration can be used to compare the effects of water stress on the gas exchange response of five different maple cultivars, including four red maple genotypes, `Summer Red', `October Glory', `Autumn Flame', and `Franksred' (Red Sunset), as well as one hybridized Freeman maple genotype, `Jeffersred' (Autumn Blaze). Cloned genotypes of red and Freeman maple were subjected to two treatments: 1) irrigated daily to container capacity or 2) irrigation withheld for one drought and recovery cycle. Leaf abscisic acid concentration, gas exchange, and whole-tree sap flow measurements were conducted under both conditions. Over the course of the drought stress and recovery phase, net photosynthesis (Anet), stomatal conductance (gs), and transpiration (E) declined as ABAL and instantaneous water use efficiency (A/gs) increased. This study found that ABAL tracked gs and that stomatal responsiveness to substrate moisture deficit is likely mediated by ABA accumulation in leaf tissue. This research demonstrates a leaf-level physiological response to substrate volumetric water content that appears to depend on ABAL concentration. In addition, the evidence in this study indicates that ABAL may be used as a potential surrogate for the gs response to substrate water stress and could become part of a cultivar drought tolerance selection strategy for red and Freeman maple.

Leaf Abscisic Acid Accumulation in Response To Substrate Water Content: Linking Leaf Gas Exchange Regulation with Leaf Abscisic Acid Concentration

Quantitative differences in leaf abscisic acid (ABAL) among four cultivars of red maple (Acer rubrum L.) and one freeman maple (Acer ×freemanii E. Murray) cultivar were investigated. This study tested the hypothesis that ABAL concentration can be used to compare the effects of water stress on the gas exchange response of five different maple genotypes, including four red maple cultivars [`Summer Red', `October Glory', `Autumn Flame', and `Franksred' ('Red Sunset')] and one hybridized freeman maple cultivar ['Jeffersred' ('Autumn Blaze')]. Two-year-old cloned genotypes of red maple and freeman maple were subjected to two treatments: irrigated daily to container capacity or irrigation withheld for one drought and recovery cycle. Leaf abscisic acid concentration, gas exchange, and wholetree sap flow measurements were conducted under well-watered and drought stress conditions. Over the course of the drought stress and recovery phase, net photosynthesis (Anet), stomatal conductance (gs), and transpiration (E) declined as ABAL and instantaneous water use efficiency (A/gs) increased. Until severe water stress conditions were prominent, water use was higher in `Summer Red' as compared to `October Glory'. This study found that ABAL tracked gs and that stomatal responsiveness to substrate moisture deficit is likely mediated by ABA accumulation in leaf tissue. This research demonstrates a leaf level physiological response to substrate volumetric water content that appears to depend on ABAL concentration. In addition, the evidence in this study indicates that ABAL may be used as a potential surrogate for the gs response to substrate water stress and could become part of a cultivar drought tolerance selection strategy for red maple and freeman maple.

THE EFFECTS OF DIFFERENT FERTILIZER APPLICATIONS ON Acer rubrum `AUTUMN BLAZE' AND Acer rubrum `RED SUNSET'ON POT-IN-POT NURSERY PRODUCTION

Kentucky West Nursery Cooperative, producers of pot-in-pot trees, needed recommendations on slow-release fertilizer applications due to regional environmental influences affecting production. Murray State University established a pot-in-pot tree nursery to research these influences in 2004. Two different fertilizer applications in three different treatments were tested on one-year old bare-root whips of Acer rubrum `Red Sunset' and `Autumn Blaze'. These trees were planted in 100% pine bark in 15-gallon pots and placed in the sockets with a complete random split-block design. Drip irrigation by spray stakes watered each pot. Nursery floor was kept clean by landscape fabric. New growth was pruned as needed to keep the trees within nursery standards. Tree calipers were measured on 1 Apr. and 1 Dec. 2004 at the beginning and end of growth. Leaves for chlorophyll readings were randomly selected to measure nitrogen uptake in late summer. Measurements were analyzed by SAS 9.1 and results found no significant differences among the treatments either in caliper increase or in chlorophyll levels (SAS, 2002). This experiment recommends a treatment using one application of slow-release fertilizer, versus split or additional applications, provides equal, quality growth of Acer rubrum `Autumn Blaze' and `Red Sunset'. The information gathered will direct fertilizer applications for KWNC and reduce their labor costs.