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Gregory E. Bell, Dennis L. Martin, Kyungjoon Koh, and Holly R. Han

, density, and overall quality by human visual evaluation is subjective and time consuming ( Bell et al., 2002a ; Trenholm et al., 1999a ). In addition, visual evaluators may be distracted by mowing patterns, rating direction, cloudiness, shadows, and turf

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Shangchun Hu, Gail Hansen, and Paul Monaghan

of which was installing a vegetative buffer. Using upland plantings around pond shorelines for visual quality can reduce fertilized areas and allow nutrient uptake from yards ( Keddy, 2000 ; Northeastern Illinois Planning Commission, 1996 ). Using

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Shannon Rauter, Youping Sun, and Melanie Stock

significance at α = 0.05. Linear and quadratic trend analysis was performed. All statistical analyses were performed using JMP (version 13.2; SAS Institute, Cary, NC). Results and discussion Plant growth and visual quality Average leaf

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Youping Sun, Ji Jhong Chen, Haifeng Xing, Asmita Paudel, Genhua Niu, and Matthew Chappell

temperature before EC measurements were taken. Three containers per treatment per taxon were randomly selected and sampled for each harvest date. Visual quality of each plant was recorded at both harvest dates using a five-point scale (visual score), where 0

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Ian R. Rodriguez and Grady L. Miller

Because high rates of nitrogen fertility are necessary for producing high-quality turfgrasses, quick, reliable methods of determining the N status of turfgrasses would be valuable management tools. The objective of this study was to evaluate the capacity of a hand-held chlorophyll meter (SPAD-502) to provide a relative index of chlorophyll concentrations, N concentrations, and visual quality in St. Augustinegrass [Stenotaphrum secondatum (Walt.) Kuntze]. Two experiments were conducted in a greenhouse in 1998 to evaluate the utility of SPAD readings. Established pots of `Floratam' were subjected to weekly foliar Fe treatments at Fe rates of 0 and 0.17 kg·ha–1 for 4 weeks. Six weekly nitrogen fertilizer treatments were applied in the form of ammonium sulfate at N rates of 0, 5.75, 11.5, 17.25, and 23 kg·ha–1 for 4 weeks. Greenhouse SPAD readings were not affected by Fe treatment, but N treatments resulted in differences in SPAD readings, visual quality, and chlorophyll concentrations. The readings were positively correlated with chlorophyll concentrations (r 2 = 0.79), visual ratings (r 2 = 0.74), and total Kjeldahl nitrogen (TKN) (r 2 = 0.71). Readings taken from field-grown `Floratam', `Floratine', and `Floralawn' St. Augustinegrass were poorly correlated (r 2 < 0.63) with chlorophyll concentrations and TKN. Unless future techniques improve dependability of the SPAD meter under field conditions for measuring chlorophyll and N concentration of a stand of turfgrass, the usefulness of such readings for the management of St. Augustinegrass seems limited.

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Sandra B. Wilson, Laurie K. Mecca, Mack Thetford, and Josiah S. Raymer

Plant growth, visual quality and flowering were assessed for 14 butterfly bush (Buddleja) taxa planted in western Florida (Milton) and central southern Florida (Fort Pierce). In both locations, `Violet Eyes' butterfly bush (B. weyeriana × B. lindleyana), `Honeycomb' butterfly bush (B. × weyeriana), `Moonlight' butterfly bush (B. × weyeriana), and `Sungold' butterfly bush (B. × weyeriana) generally had the greatest growth index and shoot dry weight of all cultivars. In Fort Pierce and Milton, flower dry weights of `White Profusion' butterfly bush (B. davidii), `Nanho Alba' butterfly bush (B. davidii var. nanhoensis), and `Dartmoor' butterfly bush (B. davidii × B. davidii var. nanhoensis) were among the highest as compared to other cultivars at each site, although in Milton, `Gloster' butterfly bush (B. lindleyana), japanese butterfly bush (B. japonica) and `Honeycomb' butterfly bush also had high flower dry weights. Peak plant performance varied by month, cultivar and location. At 12 weeks, plant form and color were above average for each cultivar with the exception of `Black Knight' butterfly bush (B. davidii), lindley's butterfly bush (B. lindleyana), and `Gloster' butterfly bush in the Fort Pierce location only. After 24 weeks at each location, visual quality was above average for `Black Knight', `Dartmoor', `Gloster', `Honeycomb', `Violet Eyes', and japanese butterfly bush. Peak flowering times varied with cultivar and location. At 24 weeks, flowering of `White Profusion', `Nanho Alba', `Nanho Blue', and `Nanho Purple' butterfly bush grown in Fort Pierce was 25% to 40% less than that of the same cultivars grown in Milton. At 24 weeks, `Dartmoor' had the most flowers in both locations, covering 75% of the plant canopy.

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S.W. Han, J.A Juvik, L.A. Spomer, and T.W. Fermanian

Plant growth regulators are becoming important tools for managing high-quality turf. However, long-term suppression of growth might affect the potential of the turf to recuperate from summer stresses. This study was initiated to determine the impact of popular commercial turfgrass growth regulators (TGR) on the accumulation of total nonstructural carbohydrates (TNC), and their effect on turf quality. Three experiments, one each year from 1994 through 1996, were conducted on creeping bentgrass (Agrostis stolonifera Huds. `Penncross') in a greenhouse. Growth retardants evaluated included trinexapac-ethyl at 0.28 kg·ha-1, flurprimidol at 0.56 kg·ha-1, and paclobutrazol at 0.28 kg·ha-1. Each retardant was applied at three different intervals: a single initial application or multiple applications every 2 or 4 weeks, for the first 8 weeks of each experiment. The verdure and roots were harvested and analyzed for TNC. Trinexapac-ethyl, flurprimidol, and paclobutrazol significantly increased the TNC of creeping bentgrass 2 weeks after their initial application, but TNC levels began to decrease at week 4. The TNC content was strongly influenced by TGR application rate but not application intervals. A single trinexapac-ethyl application at 0.28 kg·ha-1 reduced TNC content more than did split applications, each at lower rates. Accordingly, TNC levels recovered more rapidly with lower, more frequent application rates; however, the retardation effect on vegetative growth diminished as the concentration was lowered. On the other hand, repeated low application rates of trinexapac-ethyl may have minimal effect on TNC accumulation. Chemical names used: [4(cyclopropyl-α-hydroxy-methylene)-3,5-dioxocyclohexanecarboxylic acid ethyl ester] (trinexapac-ethyl); {α-[1-methylethyl]-α-[4-(trifluoro-methoxy)phenyl]-5-pyrimidine-m ethanol}(flurprimidol);[(2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-1,2,4,-t riazole-1-yl)penta-n-3--ol] (paclobutrazol).

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Landon D. Bunderson, Paul G. Johnson, Kelly L. Kopp, and Adam Van Dyke

Evaluating aesthetic qualities of turfgrass can be difficult because quality is not measured quantitatively, but is measured subjectively by visual estimation ( Skogley and Sawyer, 1992 ). This human-based visual evaluation attempts to incorporate

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Nickolee Zollinger, Richard Koenig, Teresa Cerny-Koenig, and Roger Kjelgren

( g S ) and photosynthesis rates ( Kerstiens et al., 2002 ; Rivelli et al., 2002 ; Wang and Nii, 2000 ), and damage or death of leaves ( Munns, 2002 ). Because many of the common responses to salinity decrease the visual quality of the plant

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Xuetong Fan and Kimberly J.B. Sokorai

adversely affect visual quality of lettuce during cold storage in air. In our previous study ( Fan and Sokorai, 2002 ), fresh-cut Iceberg lettuce was irradiated at doses up to 4 kGy in MAP, and it was found that overall visual appearance of lettuce