Abstract
This study was conducted to determine the effect of air anions on lettuce growth in a plant factory. Red leaf lettuce (Lactuca sativa L. cv. ‘Jeokchima’) seedlings grown under normal growth conditions (20°C, fluorescent lamp, 150 ± 3 μmol·m−2·s−1 PPFD, 12-h photoperiod) for 18 days were transplanted to hydroponic systems in a plant factory equipped with LEDs (red:blue = 78:22, 184 ± 2 μmol·m−2·s−1 PPFD, 12-h photoperiod). Three levels of air anions (low, 10 × 104 ion·cm−3; medium, 19 × 104 ion·cm−3; and high, 70 × 104 ion·cm−3) were applied to lettuce plants for 4 weeks. Lettuce plants exposed to air anions showed vigorous growth after 2 and 4 weeks of treatment. Both the medium and high levels of air anions improved growth characteristics such as leaf area and fresh weight of shoots, but there were no significant differences in the number of leaves and SPAD values were observed between the treatments. The medium level of air anions resulted in a 64% increase in shoot fresh weight compared to the control at 4 weeks after treatment. The photosynthetic rate of lettuce grown in the medium level of air anions after 3 weeks of treatment was 30% higher than that of the control. In addition, energy use efficiency in air anion treatments was higher than that in the control. In conclusion, this study demonstrated that the application of air anions in a plant factory imparts a positive effect on lettuce growth with low production cost.
Literature Cited
Chee, C.K. 2009. Effect of negative ion. 2nd ed. Living Books, Namyangju, Korea.
Cho, Y.Y. and J.E. Son. 2007. Estimation of leaf number and leaf area of hydroponic pak-choi plants (Brassica campestris spp. chinensis) using growing degree-days. J. Plant Biol. 50:8–11.
Choi, K.Y., Y.B. Lee, and Y.Y. Cho. 2011. Allyl-isothiocyanate content and physiological responses of Wasabia japonica Matusum as affected by different EC levels in hydroponics. Kor. J. Hort. Sci. Technol. 29:311–316.
Elkiey, T.M., L.R. Pelletier, S. Bhartendu, and N. Barthakur. 1977. Effects of small air ions on net blotch disease of barley. Int. J. Biometeor. 21:1–6.
Elkiey, T.M., S. Bhartendu, and N. Barthakur. 1985. Air ion effect on respiration and photosynthesis of barley and Antirrhinum majus. Int. J. Biometeor. 29:285–292.
Kang, J.G, S.Y. Yang, B.S. Lee, and S.J. Chung. 2003. Effects of changing fertilizer concentrations and fertigation frequencies on growth and fruiting of subirrigated ornamental pepper. J. Kor. Soc. Hort. Sci. 44:523–529.
Kim, D.E., Y.S. Chang, J.G. Kim, H.H. Kim, D.H. Lee, and J.T. Chang. 2006. Environmental control of plant production factory using programmable logic controller and computer. J. Bio-Environ. Cont. 15:1–7.
Kim, H.R. and Y.H. You. 2013. Effect of red, blue, white, and far-red LED source on growth responses of Wasabia japonica Seedlings in plant factory. Kor. J. Hort. Sci. Technol. 31:415–422.
Kellogg, E.W. 1984. Air anion: their possible biological significance and effects. J. Bioelectric. 3:119–136.
Kotaka, S. 1978. Effects of air ions on microorganisms and other biological materials. Critical Rev. Microbiol. 6:109–149.
Krueger, A.P., S. Kotaka, and C.P. Andriese. 1962. Studies on the effects of gaseous ions on plant growth. I. The influence of positive and negative air ions on the growth of Avena sativa. J. Gen. Physiol. 45:879–895.
Krueger, A.P., S. Kotaka, and C.P. Andriese. 1963a. A Study of the mechanism of air-ion-induced growth stimulation in Hordeum vulgaris. Int. J. Biometeor. 7:17–25.
Krueger, A.P., S. Kotaka, and C.P. Andriese. 1963b. Gaseous-ion-induced stimulation of cytochrome c biosynthesis. Nature 200:707–708.
Krueger, A.P., S. Kotaka, and C.P. Andriese. 1964. Studies on air-ion-enhanced iron chlorosis I. Active and residual iron. Int. J. Biometeor. 8:5–16.
Krueger, A.P., S. Kotaka, and C.P. Andriese. 1965. Air ion effects on the oxygen consumption of barley seedlings. Nature 208:1112–1113.
Kwon, J.K., J.C. Park, J.H. Lee, D.K. Park, Y.H. Choi, and M.A. Cho. 2003. Physiological changes and antioxidant enzyme activities of fruit vegetable plug transplants irradiated with different UV-B intensities. J. Kor. Soc. Hort. Sci. 44:464–469.
Lenard, P. 1892. The electricity of waterfalls. Ann. Phys. Lpz. 46:584–636.
Murr, L.E. 1965. Plant growth response in an electrokinetic field. Nature 207:1177–1178.
Murr. L.E. 1966. Physiological stimulation of plants using delayed and regulated electric field environments. Int. J. Biometeor. 10:147–153.
Park, B.S. 2006. Characteristics of negative ions generated by Lenard effect. J. Natural Sci. The University of Suwon 5:38–43.
Son, K.H., J.H. Park, D. Kim, and M.M. Oh. 2012. Leaf shape index, growth, and phytochemicals in two leaf lettuce cultivars grown under monochromatic light-emitting diodes. Kor. J. Hort. Sci. Technol. 30:664–672.
Um, Y.C., S.S. Oh, J.G. Lee, S.Y. Kim, and Y.A. Jang. 2010. The development of container-type plant factory and growth of leafy vegetables as affected by different light sources. J. Bio-Environ. Cont. 19:333–342.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Song, MJ., Kang, TH., Han, CS. et al. Air anions enhance lettuce growth in plant factories. Hortic. Environ. Biotechnol. 55, 293–298 (2014). https://doi.org/10.1007/s13580-014-1016-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13580-014-1016-3