Year: 2015
Type: article
Abstract: BACKGROUND: For commercial production of greenhouse crops under shorter day length condition, supplementary radiation has been usually achieved by the artificial light source with higher electric consumption such as high-pressure sodium, metal halide, or incandescent lamps.Light-Emitting Diodes (LEDs) with several characteristics, however, have been considered as a novel light source for plant production.Effects of supplementary lighting provided by the artificial light sources on growth of Kale seedlings during shorter day length were discussed in this experiment.METHODS AND RESULTS: Kale seedlings were grown under greenhouse under the three wave lamps (3 W), sodium lamps (Na), and red LEDs (peak at 630 nm) during six months, and leaf growth was observed at intervals of about 30 days after light exposure for 6 hours per day at sunrise and sunset.Photosynthetic photon flux (PPF) of supplementary red LEDs on the plant canopy was maintained at 0.1 (RL), 0.6 (RM), and 1.2 (RH) μmol/m 2 /s PPF.PPF in 3 W and Na treatments was measured at 12 μ mol/m 2 /s.Natural light (NL) was considered as a control.Leaf fresh weight of the seedlings was more than 100% increased under the 3 W, Na and RH treatment compared to natural light considering as a conventional condition.Sugar synthesis in Kale leaves was significantly promoted by the RM or RH treatment.Leaf yield per 3.3 m 2 exposed by red LEDs of 1.2 μmol/m 2 /s PPF was 9% and 16% greater than in 3W or Na with a higher PPF, respectively.CONCLUSION: Growth of the leafy Kale seedlings were significantly affected by the supplementary radiation provided by three wave lamp, sodium lamp, and red LEDs with different light intensities during the shorter day length under greenhouse conditions.From this study, it was suggested that the leaf growth and secondary metabolism of Kale seedlings can be controlled by supplementary radiation using red LEDs of 1.2 μmol/m 2 /s PPF as well as three wave or sodium lamps in the experiment.
Language: English
Topic: Light effects on plants
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: hybrid
Funder: Rural Development Administration
OpenAlex ID: W2061143671