Effects of RED and FAR-RED LED On the Growth and Fruit Quality of 'fuji' Apple Cultivars

As the Light Emitting Diodes (LED) industry improves, its price decreases thus, some farmers take advantage of its application in crop production. One application is the use of RED LED in greenhouses and open fields in order to increase productivity of crops regardless of weather conditions. The aim of this study is to find out the effects of RED and FAR-RED LED lighting on the growth and fruit quality of ten-year old 'Fuji'/M26 apple in an apple orchard during the night after sunset for 20 weeks(from June 10 to October 10 in 2010). Treatments of the experiment consisted of Control, FAR-RED (730nm, 2 and 4 hour) and RED (620nm, 2 and 4 hour) with 20 LED/pcb/tree. Results of the study revealed that there was no difference in Pn of apple among the treatments. However, the number of growth and length of secondary shoot were significantly higher in RED LED with 4h than the Control which tends to decrease as times of FAR-RED lighting increase. Fruit size of over 300g increased more in RED LED with 2 and 4h than FAR-LED compared to the Control. In our experiment, fruit weight of the apple significantly increased due to effects of RED LED compared to the Control. However, color of the fruit was significantly promoted in FAR LED than RED LED. From this result, we concluded that RED lighting could promote more growth and development of an apple tree by increasing weight of the fruit than under the FAR-RED lighting condition, whereas FAR-RED lighting could improve coloring of fruit’s surface under the bad weather conditions just like climatic changes.