Effect of LED Supplemental Illumination on the Growth of Strawberry Plants

Effect of LED supplemental illumination on the growth of strawberry plants is presented. Four LED combination lighting systems with different LED colors and power were designed and developed for supplemental illumination of the strawberry plants cultivated in the greenhouse. The LED supplemental illumination time is 4 hours everyday. The growth parameters of the strawberry plants were measured every 7 days. The plant height, leaf number, petiole length, leaf area of the strawberry plants which cultivated with LED supplemental illumination were more superior to those cultivated under the normal condition. However, there was no significant difference in the number of blossoms and fruits. The study results indicated that the supplemental illumination with LED combination lighting systems could promote the vegetative growth of strawberry plants and the promoting effect is better with the LED power increase. LEDs combination of orange/red/blue ratio of 3:2:1 is more superior to the LEDs with red/blue ratio of 5:1. the spectrum of the former is much more similar to the absorption spectrum of the plant photosynthesis.