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Author Dzakovich, M.; Gómez, C.; Mitchell, C.
Title Tomatoes Grown with Light-emitting Diodes or High-pressure Sodium Supplemental Lights have Similar Fruit-quality Attributes Type Journal Article
Year 2015 Publication HortScience Abbreviated Journal HortScience
Volume 50 Issue 10 Pages (up) 1498-1502
Keywords Plants; greenhouse tomato production; HPS; LED; physicochemical testing; sensory panels; Solanum lycopersium; tomato; high-pressure sodium; agriculture; horticulture; light-emitting diode
Abstract Light-emitting diodes (LEDs) are an attractive alternative to high-pressure sodium (HPS) lamps for plant growth because of their energy-saving potential. However, the effects of supplementing broad-waveband solar light with narrow-waveband LED light on the sensory attributes of greenhouse-grown tomatoes (Solanum lycopersicum) are largely unknown. Three separate studies investigating the effect of supplemental light quantity and quality on physicochemical and organoleptic properties of greenhouse-grown tomato fruit were conducted over 4- or 5-month intervals during 2012 and 2013. Tomato cultivars Success, Komeett, and Rebelski were grown hydroponically within a high-wire trellising system in a glass-glazed greenhouse. Chromacity, Brix, titratable acidity, electrical conductivity (EC), and pH measurements of fruit extracts indicated plant response differences between lighting treatments. In sensory panels, tasters ranked tomatoes for color, acidity, and sweetness using an objective scale, whereas color, aroma, texture, sweetness, acidity, aftertaste, and overall approval were ranked using hedonic scales. By collecting both physicochemical as well as sensory data, this study was able to determine whether statistically significant physicochemical parameters of tomato fruit also reflected consumer perception of fruit quality. Sensory panels indicated that statistically significant physicochemical differences were not noticeable to tasters and that tasters engaged in blind testing could not discern between tomatoes from different supplemental lighting treatments or unsupplemented controls. Growers interested in reducing supplemental lighting energy consumption by using intracanopy LED (IC-LED) supplemental lighting need not be concerned that the quality of their tomato fruits will be negatively affected by narrow-band supplemental radiation at the intensities and wavelengths used in this study.
Address Department of Horticulture and Landscape Architecture, Purdue University, 625 Agriculture Mall Drive, West Lafayette, IN 47907-2010
Corporate Author Thesis
Publisher American Society for Horticultural Science Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-5345 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1301
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Author Xu, C.; Wang, H.-J.; Yu, Q.; Wang, H.-Z.; Liang, X.-M.; Liu, M.; Jeppesen, E.
Title Effects of Artificial LED Light on the Growth of Three Submerged Macrophyte Species during the Low-Growth Winter Season: Implications for Macrophyte Restoration in Small Eutrophic Lakes Type Journal Article
Year 2019 Publication Water Abbreviated Journal Water
Volume 11 Issue 7 Pages (up) 1512
Keywords Plants
Abstract Eutrophication of lakes is becoming a global environmental problem, leading to, among other things, rapid reproduction of phytoplankton, increased turbidity, loss of submerged macrophytes, and the recovery of these plants following nutrient loading reduction is often delayed. Artificial light supplement could potentially be a useful method to help speeding up recovery. In this study, three common species of submerged macrophytes, Vallisneria natans, Myriophyllum spicatum and Ceratophyllum demersum, were exposed to three LED light treatments (blue, red and white) and shaded (control) for 100 days (from 10 November 2016 to 18 January 2017) in 12 tanks holding 800 L of water. All the three LED light treatments promoted growth of the three macrophyte species in terms of shoot number, length and dry mass. The three light treatments differed in their effects on the growth of the plants; generally, the red light had the strongest promoting effects, followed by blue and white. The differences in light effects may be caused by the different photosynthetic photon flux density (PPFD) of the lights, as indicated by an observed relationship of PPFD with the growth variables. The three species also responded differently to the light treatments, V. natans and C. demersum showing higher growth than M. spicatum. Our findings demonstrate that artificial light supplement in the low-growth winter season can promote growth and recovery of submerged macrophytes and hence potentially enhance their competitiveness against phytoplankton in the following spring. More studies, however, are needed to elucidate if LED light treatment is a potential restoration method in small lakes, when the growth of submerged macrophytes are delayed following a sufficiently large external nutrient loading reduction for a shift to a clear macrophyte state to have a potential to occur. Our results may also be of relevance when elucidating the role of artificial light from cities on the ecosystem functioning of lakes in urban areas.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-4441 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2606
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Author Apostol, K.; Dumroese, R.K.; Pinto, J.R.; Davis, A.S.
Title Response of conifer species from three latitudinal populations to light spectra generated by light-emitting diodes and high-pressure sodium lamps Type Journal Article
Year 2015 Publication Canadian Journal of Forest Research Abbreviated Journal Can. J. For. Res.
Volume 45 Issue 12 Pages (up) 1711-1719
Keywords plants
Abstract Light-emitting diode (LED) technology shows promise for supplementing photosynthetically active radiation (PAR) in forest nurseries because of the potential reduction in energy consumption and an ability to supply discrete wavelengths to optimize seedling growth. Our objective was to examine the effects of light spectra supplied by LED and traditional high-pressure sodium (HPS) lamps on growth and physiology of Pseudotsuga menziesii (Douglas-fir) and Picea engelmannii (Engelmann spruce) seedlings. We used three latitudinal sources for each species: British Columbia (BC), Idaho (ID), and New Mexico (NM). Container seedlings were grown for 17 weeks in the greenhouse under an 18-h photoperiod of ambient solar light supplemented with light delivered from HPS or LED. In general, seedlings grown under LED had significantly greater growth, gas exchange rates, and chlorophyll contents than those seedlings grown under HPS. The growth and physiological responses to supplemental lighting varied greatly among species and seed sources. Generally, LED-grown seedlings from BC had the greatest growth and tissue dry matter followed by ID and NM populations. Compared with HPS, the significant increase in seedling growth and concomitant energy savings with LED (29% energy consumption relative to HPS) demonstrates the promise of using LED as PAR supplemental lighting for container seedling production.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0045-5067 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1250
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Author Maggi, E.; Bertocci, I.; Benedetti-Cecchi, L.
Title Light pollution enhances temporal variability of photosynthetic activity in mature and developing biofilm Type Journal Article
Year 2020 Publication Hydrobiologia Abbreviated Journal Hydrobiologia
Volume 847 Issue 7 Pages (up) 1793-1802
Keywords Plants; Ecology
Abstract Artificial light at night (ALAN) has been recently recognized as a threat for aquatic systems, but a comprehensive knowledge of its effects is still lacking. A fundamental question is whether and how ALAN might affect temporal variability of communities, thus undermining the stability of mature assemblages or influencing the colonization process. Here we investigated the role of ALAN on temporal variability of total biomass and maximum photosynthetic efficiency of marine autotrophic biofilms colonizing Mediterranean high-shore rock surfaces while controlling for density of their main grazers. Results showed stability in total biomass, but an increase in maximum photosynthetic efficiency from unlit to lit conditions, which suggested a temporal change in composition and/or abundance of different taxa within mature assemblages. The effect was weaker during the colonization process; in this case, density of grazers acted in the opposite direction of ALAN. We suggest that the addition of light at times when it would not be naturally present may affect the temporal variability of a variety of functioning in aquatic systems, depending on species-specific sensitivities to ALAN within microbial assemblages and/or indirect effects mediated by their consumers. We highlight to further investigate the role of this emergent topic in aquatic ecology.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-8158 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number UP @ altintas1 @ Serial 3146
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Author Haag, C.R.; Riek, M.; Hottinger, J.W.; Pajunen, V.I.; Ebert, D.
Title Genetic diversity and genetic differentiation in Daphnia metapopulations with subpopulations of known age Type Journal Article
Year 2005 Publication Genetics Abbreviated Journal Genetics
Volume 170 Issue 4 Pages (up) 1809-1820
Keywords Plants; Aging; Animals; Daphnia/*genetics/*physiology; *Genetic Variation; *Genetics, Population
Abstract If colonization of empty habitat patches causes genetic bottlenecks, freshly founded, young populations should be genetically less diverse than older ones that may have experienced successive rounds of immigration. This can be studied in metapopulations with subpopulations of known age. We studied allozyme variation in metapopulations of two species of water fleas (Daphnia) in the skerry archipelago of southern Finland. These populations have been monitored since 1982. Screening 49 populations of D. longispina and 77 populations of D. magna, separated by distances of 1.5-2180 m, we found that local genetic diversity increased with population age whereas pairwise differentiation among pools decreased with population age. These patterns persisted even after controlling for several potentially confounding ecological variables, indicating that extinction and recolonization dynamics decrease local genetic diversity and increase genetic differentiation in these metapopulations by causing genetic bottlenecks during colonization. We suggest that the effect of these bottlenecks may be twofold, namely decreasing genetic diversity by random sampling and leading to population-wide inbreeding. Subsequent immigration then may not only introduce new genetic material, but also lead to the production of noninbred hybrids, selection for which may cause immigrant alleles to increase in frequency, thus leading to increased genetic diversity in older populations.
Address Unite d'Ecologie et d'Evolution, Departement de Biologie, Universite de Fribourg, CH-1700 Fribourg, Switzerland. christoph.haag@ed.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0016-6731 ISBN Medium
Area Expedition Conference
Notes PMID:15937138; PMCID:PMC1449778 Approved no
Call Number LoNNe @ kagoburian @ Serial 660
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