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N.K. Damayanthi Ranwala, D.R. Decoteau, and R.T. Fernandez

End-of-day (EOD) light treatments were used to study phytochrome involvement in photosynthesis and photosynthate partitioning in watermelon plants. Two-week-old plants were treated with brief low-intensity red (R) or far-red (FR) light for 9 days at the end of daily light period. Petiole elongation in the first two leaves was the first significant growth change in FR-treated plants compared to other plants after 3 days of treatments. This petiole elongation was accompanied by significantly higher photosynthate partitioning to petioles, even without increase in above-ground dry weight of plants. Net CO2 assimilation rate in the second leaf was significantly higher in FR treated plants on a weight basis after 3 days of treatments. Far-red-treated plants had lower chlorophyll content per leaf area and higher stem specific weight compared to R-treated plants after 3 and 6 days of treatments, respectively. Transpiration and stomatal conduction were higher in FR-treated plants compared to other treatments after 3 days of treatments. The EOD FR regulated growth and photosynthate partitioning patterns were reversible when FR treated plants were immediately followed by R. This implies EOD R: FR ratio acting through the phytochrome regulates the growth and development processes in watermelon plants.

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A. Otero, R. Perry, F. Ewers, and R.T. Fernandez

A swelling of the rootstock shank, described as Root Mass Proliferation, has been frequently found in the field on apple trees of Mark rootstock. Swelling usually first appears on trees after they have been established for more than 3 years. The abnormal growth occurs above the soil line on the exposed rootstock shank and it extends to a depth of 10 - 15 cm below soil. Anatomical studies were conducted on maiden nursery trees and trees having been in the orchard for 3 to 6 years with light microscopy. In older trees, changes in normal tissue development occurred in the 2-4 cm outer zone of the swelling surface. Changing direction and proportion of xylem components gives an appearance of tracheiry elements developing in a circular pattern. Abnormal xylem parenchyma seems to have its origin at the xylem parenchyma rays, which follow a straight plain of cell division. Clusters of lignified root initiation points are often found in the outer part of xylem, all around the rootstock shank. Removal of bark and phloem exposes hard nodules, which were found to consist of tracheiry elements surrounded by lignified parenchyma cells all between xylem and phloem tissue encircling the rootstock shank. Abnormal development of xylem vessels suggests that there is an anatomical association between water transport and a reported physiological drought sensitivity of trees on this rootstock.

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R. T. Fernandez, R. L. Perry, and D. C. Ferree

The 1980 NC-140 uniform apple rootstock trial plantings located in Michigan and Ohio were used to determine root distribution patterns of the nine rootstooks involved in the trial. The scion for the trial was Starkspur Supreme (Malus domestica Borkh.) on Ottawa 3, M.7 EMLA, M.9 EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC 9, MAC 24 and OAR 1 rootstock. Trenches were established parrallel with the tree rows 0.8 m from the center of the trunks on both sides. The trenches were 1.5 to 2 m deep. Grids were constructed 1.2 m deep × 1.8 m wide with 30 cm × 30 cm grid squares. Soil was washed from the profile and the grid was placed over the profile. Roots were classified into 3 size categories; less than 2 mm, 2 to 5 mm and greater than 5 mm. Soil physical properties were also characterized. Differences were found between rootstock root distribution patterns and will be discussed in relation to rootstock and location/soil properties.

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Jason B. London, Ted Whitwell, and R.T. Fernandez

In 1993, Carolina Nurseries and the Dept. of Horticulture at Clemson Univ. entered into a partnership for a research and development program to solve short- and long-term production problems in the ornamental nursery industry. Carolina Nurseries, located near Charleston, S.C., is a 110-ha commercial container-grown landscape plant nursery that sells >12 million units yearly. Research is conducted on site in a specially designed area that provides nursery conditions and control of other variables, including water and pesticide applications. An on-site graduate student works cooperatively with faculty on campus and manages the research area, collects data, maintains the projects using standard nursery practices, interacts with Carolina Nurseries personnel, and initiates needed studies. Over the past 6 years, research diversity increased with cooperative efforts from faculty in the Depts. of Entomology, Pathology, and Agricultural Engineering. In addition, cooperative studies with faculty members with Univ. of Georgia, Michigan State Univ., and North Carolina State Univ. have been completed. Research results were presented to the nursery industry at research update meetings at the research area site. Approximately 200 attendees from commercial nurseries and horticulture-related companies in surrounding states attended the 1998 research update. Surveys collected at research updates are helpful in tailoring research to the specific needs of the nursery industry, and are the basis for some of the current research projects. Research results are also in published in the Southern Nursery Association Research Proceedings, Journal of Environmental Horticulture, and The South Carolina Nurseryman Newsletter.

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R.T. Fernandez, R.M. McLean, R.L. Perry, and J.A. Flore

`Jonnee' on M.9 EMLA, M.26 EMLA and Mark rootstocks were subjected to flooding for 2, 4, 8, 16 and 32 days duration. Recovery was monitored after each stress period until 28 days after the 32 day flood stress. The objectives were to determine growth and physiological adaptation of the three rootstocks to flooding. Gas exchange, root dynamics, leaf area and emergence, and shoot length were measured for each stress and recovery period. CO2 assimilation initially was increased for flooded treatments of Mark and M.9 EMLA up to 300% and 200% of controls until three days after flooding. After 4 days of flooding, CO2 assimilation decreased to 30% or less of controls for both rootstocks. No initial increase was seen for flooded M.26 EMLA, rather a steady decline until net respiration occurred. Root number was not affected until 32 days of flooding where all flooded treatments had fewer roots counted compared to controls. After release from flooding trees on Mark recovered root growth while M.9 EMLA and M.26 EMLA continued to decline in root numbers. Shoot system growth of flooded trees on M.26 EMLA was reduced first and to the greatest extent followed by Mark and then M.9 EMLA.

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M.W. Duck, B.M. Cregg, R.T. Fernandez, R.D. Heins, and F.F. Cardoso

Tabletop Christmas tree growers whose greenhouse-grown conifers have undesirable shoot growth may alleviate this problem by applying plant growth retardants (PGRs). Some of the most common PGRs in the horticulture industry were evaluated to determine their effectiveness in controlling plant height: ancymidol at 100 μL·L-1 (ppm), daminozide at 5000 μL·L-1, paclobutrazol at 60 μL·L-1, chlormequat at 1500 μL·L-1, uniconazole at 15 μL·L-1, and ethephon at 500 μL·L-1 compared to a nontreated control. The following conifer species were used: colorado blue spruce (Picea pungens), black hills spruce (P. glauca var. densata), serbian spruce (P. omorika), noble fir (Abies procera), grand fir (A. grandis), fraser fir (A. fraseri), concolor fir (A. concolor), arborvitae (Thuja occidentalis), port orford cedar (Chamaecyparis lawsoniana), and douglas-fir (Pseudotsuga menziesii). Chlormequat was the only PGR that caused phytotoxicity and damage to the foliage was minimal. Noble fir, douglas-fir, colorado blue spruce, and arborvitae were unaffected by any PGR treatment. Daminozide reduced growth of port orford cedar and concolor fir; uniconazole reduced growth of black hills spruce and serbian spruce; paclobutrazol reduced growth of fraser fir; and ethephon reduced growth of grand fir.

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Bridget K. Behe, Melinda Knuth, Charles R. Hall, Patricia T. Huddleston, and R. Thomas Fernandez

The strain on potable water supplies heightens the competition for water resources and potentially reduces the demand for outdoor plantings and landscaping. We conducted an online survey with 1543 respondents in 2016 to ascertain their water conservation and plant expertise, their involvement in water conservation and plant issues, and the importance of plants and landscaping. We also collected demographic characteristics. Cluster analysis results identified two key market segments comprising ≈50% of the sample each: those who are Actively Interested in Water Conservation and those who are Disinterested in Water Conservation. The Actively Interested segment was younger, had more adults and children in the household, and had a higher household income. In addition to having a higher mean score for water conservation involvement and expertise, the Actively Interested segment had a higher mean score for water conservation importance and impact, as well as plant expertise and involvement. The Actively Interested segment scored higher on select components relating to horticultural importance, including aesthetically beautiful landscapes, active landscape enjoyment, desire for a low maintenance landscape, and response in drought, compared with the Disinterested segment. The Disinterested segment scored higher on the Non-Landscape Use with no enjoyment. Findings suggest that pro–water-conserving attitudes are found among consumers who value outdoor landscapes and those individuals who spend more on plants. Results suggest that producers and retailers should focus marketing and communication efforts on low water use cultivar selection and operationalizing water-conserving behaviors more than convincing consumers that plant purchases and landscaping are important.

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Melinda Knuth, Bridget K. Behe, Charles R. Hall, Patricia T. Huddleston, and R. Thomas Fernandez

Activity level, or the amount of action/interaction with a product, can be an indication of interest in a product category and influences purchases. Our goal was to assess the overall market for landscape plants using consumers’ activity level from the active/passive continuum proposed by . An online survey instrument was administered to invitees from a national online panel from 7 to 13 Sept. 2016 yielding 1543 useful responses. Factor analysis of 23 items adapted from a previous study revealed five factors, including one active factor and a separate passive factor. These two factors were used in the present study as a basis for a k-means cluster analysis. Two clusters emerged and were labeled “Active Engagement” and “Obligatory Passive Engagement” in landscape activities. We compared cluster means for all five factors and found the Active cluster purchased more plants of all types as well as had greater landscape pride and desire for a low (water) input landscape. Members of the Active cluster were from higher income and education households which were slightly larger and more likely to have Caucasian residents compared with the Passive cluster. In practice, retail employees and landscape professionals might initially ask about consumers’ activity level desired in the landscape as a screening question. Subsequent assistance in design and/or plant selection/purchase could then be tailored toward the desired activity level.

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Melinda Knuth, Bridget K. Behe, Charles R. Hall, Patricia T. Huddleston, and R. Thomas Fernandez

In the coming decades, no natural resource may prove to be more critical to human health and well-being than water. There is abundant evidence that the condition of water resources in many parts of the United States is deteriorating. In some regions of the country, the availability of sufficient water to meet growing domestic uses, and the future sufficiency of water to support the use of landscape plants where we live, work, and play is in doubt. Conservation through water efficiency measures and water management practices may be the best way to help resolve water problems. Yet, consumer perceptions and attitudes and behavior toward water conservation may differ widely, particularly in the presence of drought. This study sought to add to the current horticulture and water conservation literature by exploring consumer attitudes and behavior during real and perceived drought situations, especially in terms of their landscape purchases and gardening/landscaping activities. Study findings could better inform educational programs and marketing strategies, helping to ensure the future demand of Green Industry products and services. With a national sample of 1543 subjects, an online survey tool was used to classify respondents into categories based on whether they accurately perceived if the region in which they lived was experiencing drought. We hypothesized that consumers were heterogeneous in their attitudes and behavior regarding plants and water conservation, depending on their real and perceived drought situations, and that their attitudes affected their behavior regarding plant purchases. Results confirmed this hypothesis. Attitudes and behaviors for those who correctly perceived they were in drought were different from those who correctly perceived they were not in drought, as well as those who incorrectly did not perceive they were in an actual drought.

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Karl J. Muzii, M. Haque, R.T. Fernandez, B. Behe, and S. Barton

The research contained in this thesis quantifies the difference between actual landscape value and perceived value on the part of homeowners. Pertinent information and necessary data were gathered by surveys interviewing consumers over the age of 18, who evaluated a set of 16 home landscape photographs. These surveys were conducted at two sites in South Carolina. The study involved three levels of landscape design with varying complexity and cost factors. Four plant material and hardscape combinations were developed for use in each cost design. Finally, the plant material size was categorized as small, medium, or large. Thirty-six design combinations were created. A subset of 16 computer-generated images was selected to simplify the evaluation. Participating respondents answered a questionnaire providing personal demographic information and their evaluations of the 16-image subset. Participants were supplied a base starting price and a photo of the home without landscaping. Responses were analyzed to determine consumer perceptions of value influenced by landscape design style, plant material, and hardscape selection; plant size; and by the difference between perceived value and actual cost to install. Consumer responses for all landscape designs were positive and indicate that consumers consider landscaping an asset to residential value. Participants valued the home on average between.95% to 11.3%, depending on the complexity of design, plant material, hardscape, and size combinations. The variance between consumer perception and actual cost of material and labor indicates that consumers undervalue the price of a newly installed landscape where all material and labor costs are priced consistent with professional landscaping averages.