Articles
Comparison of supplemental lighting from high-pressure sodium lamps or light-emitting diodes on morphology and nutrient uptake of greenhouse crops
Article number
1337_42
Pages
313 – 322
Language
English
Abstract
Supplemental lighting in greenhouses augments ambient sunlight, especially during winter and spring production to provide sufficient irradiance for desired growth.
Light-emitting diodes (LEDs) are increasingly used in place of high-pressure sodium (HPS) lamps, but growers are hesitant to switch due to price and concerns about spectral effects on growth, morphology, and nutrient uptake.
Eight greenhouse crops [basil (Ocimum basilicum Genovese Emily), geranium (Pelargonium ×hortorum Maverick Red), pansy (Viola ×wittrockiana Delta Premium Blue Blotch), pepper (Capsicum annuum California Wonder), spinach (Spinacia oleracea Whale), tomato (Solanum lycopersicum Early Girl), vinca (Catharanthus roseus Cora Burgundy), and zinnia (Zinnia marylandica Zahara Cherry)] were grown in a glass greenhouse and provided a supplemental photosynthetic photon flux density of 100 µmol m‑2 s‑1 14 h day‑1 from HPS or LED (50 blue:50 red:22 far-red) fixtures.
Plants receiving supplemental LED lighting were 11-99% taller, 4-45% wider, and had 25-143% greater dry mass than plants receiving supplemental HPS lighting.
Relative chlorophyll content was 102% higher in LED-supplemented basil, but 5-26% lower in the other seven species, compared to HPS-supplemented plants.
Foliar nutrient concentrations of LED-supplemented plants were 2% higher to 14% lower (nitrogen), 10% higher to 20% lower (phosphorus), 3-32% lower (potassium), 15% higher to 9% lower (calcium), 28% higher to 12% lower (magnesium), 11% higher to 18% lower (sulfur), 30% higher to 18% lower (boron), 23% higher to 34% lower (copper), 2-40% lower (iron), 13-41% lower (manganese), and 14% higher to 31% lower (zinc), relative to HPS-supplemented plants.
Light-emitting diodes (LEDs) are increasingly used in place of high-pressure sodium (HPS) lamps, but growers are hesitant to switch due to price and concerns about spectral effects on growth, morphology, and nutrient uptake.
Eight greenhouse crops [basil (Ocimum basilicum Genovese Emily), geranium (Pelargonium ×hortorum Maverick Red), pansy (Viola ×wittrockiana Delta Premium Blue Blotch), pepper (Capsicum annuum California Wonder), spinach (Spinacia oleracea Whale), tomato (Solanum lycopersicum Early Girl), vinca (Catharanthus roseus Cora Burgundy), and zinnia (Zinnia marylandica Zahara Cherry)] were grown in a glass greenhouse and provided a supplemental photosynthetic photon flux density of 100 µmol m‑2 s‑1 14 h day‑1 from HPS or LED (50 blue:50 red:22 far-red) fixtures.
Plants receiving supplemental LED lighting were 11-99% taller, 4-45% wider, and had 25-143% greater dry mass than plants receiving supplemental HPS lighting.
Relative chlorophyll content was 102% higher in LED-supplemented basil, but 5-26% lower in the other seven species, compared to HPS-supplemented plants.
Foliar nutrient concentrations of LED-supplemented plants were 2% higher to 14% lower (nitrogen), 10% higher to 20% lower (phosphorus), 3-32% lower (potassium), 15% higher to 9% lower (calcium), 28% higher to 12% lower (magnesium), 11% higher to 18% lower (sulfur), 30% higher to 18% lower (boron), 23% higher to 34% lower (copper), 2-40% lower (iron), 13-41% lower (manganese), and 14% higher to 31% lower (zinc), relative to HPS-supplemented plants.
Authors
J.K. Boldt, J.E. Altland
Keywords
controlled environment agriculture, floriculture, light quality, ornamental plants
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