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Author (up) Gómez, C.; Mitchell, C.A.
Title Physiological and Productivity Responses of High-wire Tomato as Affected by Supplemental Light Source and Distribution within the Canopy Type Journal Article
Year 2016 Publication Journal of the American Society for Horticultural Science Abbreviated Journal J. Amer. Soc. Hort. Sci.
Volume 141 Issue 2 Pages 196-208
Keywords Plants; tomato; LED; LED lighting; Solanum lycopersicum; intracanopy lighting; greenhouses; intracanopy supplemental lighting; daily light integral
Abstract The relative coolness-to-touch of light-emitting diodes (LEDs) has enabled commercial implementation of intracanopy lighting (ICL) in the greenhouse. Intracanopy lighting, which refers to the strategy of lighting along the side or from within the foliar canopy, can increase canopy photosynthetic activity, but physiological and productivity responses of high-wire greenhouse tomato (Solanum lycopersicum) to intracanopy supplemental lighting (SL) still are not yet fully understood. Two consecutive production experiments were conducted across seasons in a glass-glazed greenhouse located in a midnorthern, continental climate [lat. 40°N (West Lafayette, IN)]. Plants were grown from winter-to-summer [increasing solar daily light integral (DLI)] and from summer-to-winter (decreasing solar DLI) to compare three SL strategies for high-wire tomato production across changing solar DLIs: top lighting with high-pressure sodium lamps (HPS) vs. intracanopy LED vertical towers vs. hybrid SL (HPS + horizontal ICL-LEDs). A control treatment also was included for which no SL was provided. Supplemental DLI for each experimental period was adjusted monthly, to complement seasonal changes in sunlight, aiming to approach a target total DLI of 25 mol·m‒2·d‒1 during fruit set. Harvest parameters (total fruit fresh weight, number of fruit harvested, and average cluster fresh weight), tissue temperature, chlorophyll fluorescence, and stomatal conductance (gS) were unaffected by SL treatment in both experiments. Among the physiological parameters evaluated, CO2 assimilation measured under light-saturating conditions, light-limited quantum-use efficiency, and maximum gross CO2 assimilation (Amax) proved to be good indicators of how ICL reduces the top-to-bottom decline in leaf photosynthetic activity otherwise measured with top lighting only (HPS-SL or solar). Although SL generally increased fruit yield relative to control, lack of SL treatment differences among harvest parameters indicates that higher crop photosynthetic activity did not increase fruit yield. Compared with control, intracanopy SL increased yield to the same extent as top SL, but the remaining photoassimilate from ICL most likely was partitioned to maintain nonharvested, vegetative plant parts as well.
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 Engligh Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-1062 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1431
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Author (up) Grenis, K.; Murphy, S.M.
Title Direct and indirect effects of light pollution on the performance of an herbivorous insect Type Journal Article
Year 2018 Publication Insect Science Abbreviated Journal Insect Sci
Volume 26 Issue 4 Pages 770-776
Keywords Animals; Plants
Abstract Light pollution is a global disturbance with resounding impacts on a wide variety of organisms, but our understanding of these impacts is restricted to relatively few higher vertebrate species. We tested the direct effects of light pollution on herbivore performance as well as indirect effects mediated by host plant quality. We found that artificial light from streetlights alters plant toughness. Additionally, we found evidence of both direct and indirect effects of light pollution on the performance of an herbivorous insect, which indicates that streetlights can have cascading impacts on multiple trophic levels. Our novel findings suggest that light pollution can alter plant-insect interactions and thus may have important community-wide consequences.
Address Department of Biological Sciences, University of Denver, Denver, Colorado, USA
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 1672-9609 ISBN Medium
Area Expedition Conference
Notes PMID:29425403 Approved no
Call Number GFZ @ kyba @ Serial 1865
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Author (up) Grubisic, M.; Singer, G.; Bruno, M.C.; van Grunsven, R.H.A.; Manfrin, A.; Monaghan, M.T.; Hölker, F.
Title A pigment composition analysis reveals community changes in pre-established stream periphyton under low-level artificial light at night Type Journal Article
Year 2018 Publication Limnologica Abbreviated Journal
Volume 69 Issue Pages 55-58
Keywords Plants; Ecology
Abstract Freshwaters are increasingly exposed to artificial light at night (ALAN), yet the consequences for aquatic primary producers remain largely unknown. We used stream-side flumes to expose three-week-old periphyton to LED light. Pigment composition was used to infer community changes in LED-lit and control periphyton before and after three weeks of treatment. The proportion of diatoms/chrysophytes decreased (14%) and cyanobacteria increased (17%) in lit periphyton in spring. This may reduce periphyton nutritional quality in artificially-lit waters.
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 0075-9511 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ schroer @ Serial 1791
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Author (up) Grubisic, M.; van Grunsven, R.H.A.; Manfrin, A.; Monaghan, M.T.; Hölker, F.
Title A transition to white LED increases ecological impacts of nocturnal illumination on aquatic primary producers in a lowland agricultural drainage ditch Type Journal Article
Year 2018 Publication Environmental Pollution Abbreviated Journal Environmental Pollution
Volume 240 Issue Pages 630-638
Keywords Plants; Ecology
Abstract The increasing use of artificial light at night (ALAN) has led to exposure of freshwater ecosystems to light pollution worldwide. Simultaneously, the spectral composition of nocturnal illumination is changing, following the current shift in outdoor lighting technologies from traditional light sources to light emitting diodes (LED). LEDs emit broad-spectrum white light, with a significant amount of photosynthetically active radiation, and typically a high content of blue light that regulates circadian rhythms in many organisms. While effects of the shift to LED have been investigated in nocturnal animals, its impact on primary producers is unknown. We performed three field experiments in a lowland agricultural drainage ditch to assess the impacts of a transition from high-pressure sodium (HPS) to white LED illumination (color temperature 4000 K) on primary producers in periphyton. In all experiments, we compared biomass and pigment composition of periphyton grown under a natural light regime to that of periphyton exposed to nocturnal HPS or, consecutively, LED light of intensities commonly found in urban waters (approximately 20 lux). Periphyton was collected in time series (1–13 weeks). We found no effect of HPS light on periphyton biomass; however, following a shift to LED the biomass decreased up to 62%. Neither light source had a substantial effect on pigment composition. The contrasting effects of the two light sources on biomass may be explained by differences in their spectral composition, and in particular the blue content. Our results suggest that spectral composition of the light source plays a role in determining the impacts of ALAN on periphyton and that the ongoing transition to LED may increase the ecological impacts of artificial lighting on aquatic primary producers. Reduced biomass in the base of the food web can impact ecosystem functions such as productivity and food supply for higher trophic levels in nocturnally-lit ecosystems.
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 0269-7491 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1900
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Author (up) 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 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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