Increasing Growth and Yield of Sweet Basil and Holy Basil by Application of Far-Red Radiation for Indoor Horticulture

: The objective of this study is to investigate the interaction of R, B and FR from phosphor-converted LED on the growth and yield of the sweet basil and holy basil. Seedlings were grown in the chamber with a continuous supply of 200 µmolm -2 sec -1 PPFD of R and B. Several ratios were applied as R:B.3.5 and 7.0 without FR and R:B.3.5 with FR 50 µmolm -2 sec -1 . The photo period was 16/8 h. The results found that R:B.3.5 with FR50 significantly increased the growth rate by 49-114%, the plant height by 64-137%, the stem diameter by 20-25% and the total fresh weight by 98-181% of the crops. R:B.3.5 with FR50 also significantly increased the average leaf area by 59-85% for the holy basil but not in the sweet basil and increased the total dry weight by 110-253% of the sweet basil but not in the holy basil. Additionally, no effects on the leaf thickness of the crops were observed. R:B.7 without FR had the trend to promote the growth of leaf and stem and total fresh weight of the crops than R:B.3.5 without FR. Moreover, the combination of FR with the R and B light could increase the leaf expansion, stem length whole plant photosynthesis and total fresh and dry weight of the sweet basil and holy basil.