Air anions enhance lettuce growth in plant factories

作者：Song Min Jeong; Kang Tae Hwan; Han Chung Su; Oh Myung Min^*

来源：Horticulture Environment and Biotechnology, 2014, 55(4): 293-298.

DOI：10.1007/s13580-014-1016-3

• energy use efficiency
• photosynthetic rate

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. %26apos;Jeokchima%26apos;) seedlings grown under normal growth conditions (20A degrees C, fluorescent lamp, 150 +/- 3 mu mol center dot m(-2)center dot 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 mu mol center dot m(-2)center dot s(-1) PPFD, 12-h photoperiod). Three levels of air anions (low, 10 x 10(4) ion center dot cm(-3); medium, 19 x 104 ion center dot cm(-3); and high, 70 x 10(4) ion center dot 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.

• 出版日期2014-8