Articles
SOLID-STATE LAMPS (LEDS) FOR THE SHORT-WAVELENGTH SUPPLEMENTARY LIGHTING IN GREENHOUSES: EXPERIMENTAL RESULTS WITH CUCUMBER
Article number
927_90
Pages
723 – 730
Language
English
Abstract
The solid-state lighting technology based on light-emitting diodes (LEDs) offers vast possibilities in horticultural lighting.
Here we present the prototypes of short-wavelength single-monochromatic solid-state lamps developed for the supplementa¬tion of high-pressure sodium (HPS) lamps used in greenhouses.
Each lamp features high-power AlInGaN LEDs, a stabilized-current switch-mode AC/DC power supply, an optimized heat sink with lateral reflectors, and a protective lid with lenses which allows for operation in humid environments.
Four types of lamps with peak emissions at 455, 470, 505, and 530 nm were made.
Lamps were installed in a phytotron greenhouse.
Transplants of cucumber hybrid Mandy were grown in a phytotron greenhouse under natural daylight with supplemental illumination of HPS lamps and our solid-state lamps.
The biometrical measurements, assessment photosynthetic pigments and saccharides content were performed at the end of the experiment.
Our investigations revealed that the supplemental 470, 505 and 530 nm LEDs illumination with high pressure sodium lamps increased leaf area, fresh and dry weight of cucumber transplants, decreased hypocotyls elongation and enhanced their develop¬ment.
Meanwhile, the supplemental 455 nm LED illumination caused slower growth and development of cucumber transplants.
The synthesis of photosynthetic pigments mostly enhanced 455, 470 and 530 nm supplemental illumination, but supplemental green (505 and 530 nm) light slightly decreased chlorophyll a and b ratio in leaves of cucumber hybrid Mandy.
Here we present the prototypes of short-wavelength single-monochromatic solid-state lamps developed for the supplementa¬tion of high-pressure sodium (HPS) lamps used in greenhouses.
Each lamp features high-power AlInGaN LEDs, a stabilized-current switch-mode AC/DC power supply, an optimized heat sink with lateral reflectors, and a protective lid with lenses which allows for operation in humid environments.
Four types of lamps with peak emissions at 455, 470, 505, and 530 nm were made.
Lamps were installed in a phytotron greenhouse.
Transplants of cucumber hybrid Mandy were grown in a phytotron greenhouse under natural daylight with supplemental illumination of HPS lamps and our solid-state lamps.
The biometrical measurements, assessment photosynthetic pigments and saccharides content were performed at the end of the experiment.
Our investigations revealed that the supplemental 470, 505 and 530 nm LEDs illumination with high pressure sodium lamps increased leaf area, fresh and dry weight of cucumber transplants, decreased hypocotyls elongation and enhanced their develop¬ment.
Meanwhile, the supplemental 455 nm LED illumination caused slower growth and development of cucumber transplants.
The synthesis of photosynthetic pigments mostly enhanced 455, 470 and 530 nm supplemental illumination, but supplemental green (505 and 530 nm) light slightly decreased chlorophyll a and b ratio in leaves of cucumber hybrid Mandy.
Authors
A. Novičkovas, A. Brazaitytė, P. Duchovskis, J. Jankauskienė, G. Samuolienė, A. Virsilė, R. Sirtautas, Z. Bliznikas , A. Zukauskas
Keywords
cucumber, growth, photosynthesis pigments, saccharides, solid-state illumination, LEDs
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