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Tove Fjeld

Plants are widely used in building environments; however, studies reporting the health and discomfort symptoms of people in response to indoor foliage plants are few. The objective of the presented studies was to assess the effect of foliage plants or a combination of foliage plants and full-spectrum fluorescent lamps on self-reported health and discomfort complaints in three different work environments: an office building, an X-ray department in a Norwegian hospital, and a junior high school. Health and discomfort symptoms were found to be 21% to 25% lower during the period when subjects had plants or plants and full-spectrum lighting present compared to a period without plants. Neuropsychological symptoms, such as fatigue and headache, and mucous membrane symptoms, such as dry and hoarse throat, seemed to be more affected by the treatments than skin symptoms, such as itching skin.

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William J. Martin and Dennis P. Stimart

Cut flowers of Antirrhinum majus L. (snapdragon) P1, P2, F1, F3, and F2 × F2 plants were harvested after the first five flowers were open and were evaluated for postharvest longevity to further evaluate genes conditioning postharvest longevity. F3 progeny evaluated were derived by selfing F2 selections of long keeping, mid-range, and short keeping types. F2 × F2 progeny evaluated were derived from crosses within and between postharvest longevity categories. Populations for evaluation were grown in the greenhouse in winter 1998-1999 in a randomized complete-block design according to standard forcing procedures. Thirty plants of each genotype were held in the laboratory in deionized water under continuous fluorescent lighting at 22 °C for postharvest assessment. The end of postharvest life was defined as 50% of the flowers drying, browning, or wilting. Data will be presented on postharvest longevity and allelic relationships within populations.

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Robert G. Anderson

Greenhouse grown cut stems of satin flower were used in a series of postharvest experiments to determine the effect of sucrose on flower life, flower quality and the overall vaselife. Experiments in 1993 compared 0, 0.5, 1.0 and 2.0% sucrose in tap water with and without a biocide (4 ppm sodium hypochlorite). Cut stems of `Grace Rose Pink,' `Grace Salmon and `Grace Red' were harvested, stored in a refrigerator overnight at l-2” C.; all cut stems were maintained in randomized individual vases in a room kept at 22-23 C with fluorescent lighting (50 ft.c.) from 0800-2000 HR. Postharvest performance was best in tap water, tap water + biocide, and 0.5% sucrose + biocide with excellent flower opening and flower quality for 10-14 days. Leaf yellowing and leaf necrosis increased greatly with the increasing concentrations of sucrose. Flowers of `Grace Salmon' showed significant petal necrosis in the treatments with higher concentrations of sucrose.

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William J. Martin and Dennis P. Stimart

Stomatal density is being investigated as a highly correlated trait to postharvest longevity (PHL) and subsequently may be used for selection in early generations of breeding germplasm. To this end, leaf imprints were created from Antirrhinum majus L. (snapdragon) P1, P2, F1, BC1 (F1×P1), BC2 (F1×P2), F2, and F3 plants and evaluated for stomatal densities. Cut flowers of P1, P2, F1, BC1 (F1×P1), BC2 (F1×P2), and F3 were harvested after the first five flowers opened and evaluated for PHL. Additionally, cut flowers from these lines were evaluated for leaf surface area. Populations for evaluation were grown in the greenhouse in winter and spring 1999-2000 in a randomized complete-block design according to standard forcing procedures. Twenty-five cut flowering stems of each genotype were held in the laboratory in deionized water under continuous fluorescent lighting at 22 °C for PHL assessment. The end of PHL was defined as 50% of the flowers drying, browning, or wilting. Data will be presented on the correlation between stomatal density and PHL.

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Jill A. Montgomery, Ray A. Bressan and Cary A. Mitchell

Obtaining uniform mechano-dwarfing of Arabidopsis thaliana (L.) Heynh. seedlings within dense plantings is problematic. Alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls in both greenhouse and controlled growth environments. Arabidopsis grown under low photosynthetic photon flux (PPF) artificial light grew upright with limited leaf expansion, which enhanced mechano-responsiveness compared to that of rosette-growing plants under filtered sunlight or high PPF artificial light. Hypocotyls of seedlings grown at PPFs >60 μmol·m-2·s-1 elongated less and had 6% less sensitivity to mechanical stress than seedlings grown at PPFs <60 μmol·m-2·s-1. Fluorescent lamps alone (F) or fluorescent plus incandescent (F+I) lamps were compared for seedling responses to mechanical stress. Under F lighting, hypocotyl elongation was reduced 25% to 40% by twice-daily brush or plate treatments, and brushed seedlings exhibited more growth reduction than did plate treatments. Seedlings grown under F+I lamps exhibited similar stress-induced growth reduction compared to seedlings grown under F only, but stressed F+I seedlings lodged to a greater extent due to excessive hypocotyl elongation. Temperature-response studies using standardized F-only lighting indicated increased hypocotyl elongation but decreased leaf expansion, and decreased mechano-responsivity to brushing over the temperature range from 20 to 28 °C. Daylength studies indicated similar degrees of mechano-inhibition of hypocotyl elongation over the daylength range of 12, 16, 20, and 24 hours, whereas fresh weight of stressed seedling shoots declined compared to controls. A combination of environmental growth parameters that give repeatable, visual mechanical dwarfing of Arabidopsis include low-PPF fluorescent lighting from 55 to 60 μmol·m-2·s-1, ambient temperatures from 22 to 25 °C, and twice-daily brush treatments.

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James M. Garner and Allan M. Armitage

fluorescent lighting providing ≈4 μmol·s −1 ·m −2 at plant height. Plants that were to receive cooling were placed in refrigeration on 15 Oct. and removed sequentially as the requisite number of cooling weeks was achieved. Plug trays were placed directly on

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Ben A. Faber, A. James Downer, Dirk Holstege and Maren J. Mochizuki

with background 4100-K metal halide fluorescent lighting. Comparing analytical laboratory results with soil test kit results. Analysis of variance was performed on the analytical laboratory results using the SAS GLM procedure (version 9.1; SAS Institute

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Alexander Q. Susko, Timothy A. Rinehart, James M. Bradeen and Stan C. Hokanson

occurred under fluorescent lighting (Sylvania 34W E3e4 bulbs; Osram Sylvania, Inc., Mississauga, CA) with a 24-h photoperiod at a room temperature of ≈24 °C. Following germination, the photoperiod duration of the fluorescent lighting was shortened to 16 h

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Joyous Suiyigheh Tata and Hans Christian Wien

after anthesis. Flowers were harvested at first anthesis, put in glass vases with distilled water, and stored at a room temperature of 20 °C, 60% relative humidity (RH), and 12 h·d –1 fluorescent lighting. Force readings for both cultivars were taken on

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Douglas A. Phillips, Philip F. Harmon, James W. Olmstead, Natalia A. Peres and Patricio R. Munoz

dextrose agar (PDA) under continuous fluorescent lighting at 25 °C for 5 d, at which point sufficient sporulation had occurred. The petri plate containing the pathogen was flooded with distilled water, the conidia dislodged into a suspension with a