Paper Infomation
Evaluation of Growth and Quality in Latuca Sativa L. under Different Photoperiods
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Author: K.W. Lam, J.C.W. Pang, K. H. Loo, Y.M. Lai, S.Y Chau
Abstract: The growth and quality of Latuca Sativa L. (Lettuce Meraviglia d'inverno) in a closed-type plant factory system with various photoperiods under the same daylight integral (DLI) were evaluated in this study. Four groups with 12 samples each were grown hydroponically under LED light sources with DLI of 4 mol/m2/d ± 9% at 18h/6h, 12h/12h, 11h/1h and 9h/3h light/dark periods. The light sources were generated by LEDs with the wavelengths of 660 nm (red) and 450 nm (blue) under the same light intensity. In the evaluation, any occurrence of tipburn, marginal necrosis and leaf yellowing was counted as unqualified leaf. Results showed that the group under the higher photosynthetic photon flux density (PPFD) showed the highest yield and the lowest percentage of unqualified leaves under the same DLI. Under rapid photoperiod of 9h/3h, the yield increased even the PPFD was low. Low PPFD with high light dark ratio resulted in the highest percentages of physiological disorder and the lowest fresh mass. It suggests that yield of lettuce may be further increased by combining rapid photoperiods and high PPFD for the same energy cost.
Keywords: LED; Photoperiod; Tipburn; Plant factory; Growth Profile; Latuca Sativa L
References:
[1] Ki-Ho Son and Myung-Min Oh, "Leaf Shape, Growth, and Antioxidant Phenolic Compounds of Two Lettuce Cultivars Grown under Various Combinations of Blue and Red Light-emitting Diodes", HortScience August 2013 vol. 48 no. 8, pg. 988-995.
[2] Xiao-Xue Fan, Zhi-Gang Xu, Xiao-Ying Liu, Can-Ming Tang, Li-Wen Wang, Xue-lin Han, "Effects of light intensity on the growth and leaf development of young tomato plants grown under a combination of red and blue light," Scientifia Horticulturae, 2013, Vol 153, pg. 50-55.
[3] Harun, A.N.; Ani, N.N.; Ahmad, R.; Azmi, N.S., "Red and blue LED with pulse lighting control treatment for Brassica chinensis in Indoor farming," Open Systems (ICOS), 2013 IEEE Conference, 2013, pg. 231-236.
[4] Masamoto Takatsuji, Sintaro Kamaya and Takeo Enomoto, "The Effect of Photoperiodicity on the Growth of Lettuce Applied by Light-Emitting Diodes," Journal of Shita, 1996, Vol. 8, No. 2, pg. 119-121.
[5] Jeong Hwa Kang, Sugumaran KrishnaKumar, Sarah Louise Sua Atulba, Byoung Ryong Jeong and Seung Jae Hwang,” Light Intensity and Photoperiod Influence the Growth and Development of Hydroponically Grown Leaf Lettuce in a Closed-type Plant Factory System,” Hort. Environ. Biotechnol. 54(6):501-509. 2013.
[6] Jung Eek Son and Tadashi Takakura, "Effect of EC of Nutrient Solution and Light Condition on Transpiration and Tipburn Injury of Lettuce in a Plant Factory," Journal of Agricultural Meteorology 1989, Vol. 44, no. 4.
[7] Jules Janick, “Horticultural Reviews”, Avi Publishing Company, 1983, Vol 5, pg. 1-44.