Effects of Frequency and Duty Ratio on the Growth of Potato Plantlets In Vitro Using Light-emitting Diodes

Effects of intermittent light on photomixotrophic growth of potato plantlets in vitro and the electrical savings that could be realized by adjusting the frequency and duty ratio of light-emitting diodes (LEDs) were investigated and compared to the use of conventional tubular fluorescent lamps (TFLs). TFLs provide continuous fluctuating light at 60 Hz and LEDs provide continuous nonfluctuating or intermittent/pulse light depend on the preset frequency and duty ratio. In total, eight treatments were investigated with varying light source, frequency, duty ratio and photoperiod. Results indicated that if growth rate is the only concern, LEDs at 720 Hz [1.4 milliseconds (ms)] and 50% duty ratio with 16-h light/8-h dark photoperiod stimulated plant growth the most. However, if energy consumption is the major concern, using LEDs at 180 Hz (5.5 ms) and 50% duty ratio with 16-h light/8-h dark photoperiod would be the best choice for illuminating potato plantlets without significantly sacrificing plant growth, especially when energy for heat removal is also considered.

[1]  O. Warburg.  Über die Geschwindigkeit der photochemischen Kohlensäurezersetzung in lebenden Zellen. II , 1928 .

[2]  T. Sharkey,et al.  Efficiency of photosynthesis in continuous and pulsed light emitting diode irradiation , 1995, Photosynthesis Research.

[3]  R. Emerson,et al.  A SEPARATION OF THE REACTIONS IN PHOTOSYNTHESIS BY MEANS OF INTERMITTENT LIGHT , 1932, The Journal of general physiology.

[4]  T. Kozai,et al.  Time Course of CO2 Exchange of Potato Cultures In Vitro with Different Sucrose Concentrations in the Culture Medium , 1992 .

[5]  J. Franck,et al.  Photosynthesis in Flashing Light. , 1941 .

[6]  M. Jackson,et al.  Ventilation in Plant Tissue Cultures and Effects of Poor Aeration on Ethylene and Carbon Dioxide Accumulation, Oxygen Depletion and Explant Development , 1991 .

[7]  F. Skoog,et al.  A revised medium for rapid growth and bio assays with tobacco tissue cultures , 1962 .

[8]  T. Kozai,et al.  Fundamental Studies on Environments in Plant Tissue Culture Vessels , 1986 .

[9]  Wei Fang,et al.  AN ADJUSTABLE LIGHT SOURCE FOR PHOTO–PHYTO RELATED RESEARCH AND YOUNG PLANT PRODUCTION , 2003 .

[10]  Ladislav Nedbal,et al.  Microscopic green algae and cyanobacteria in high-frequency intermittent light , 1996, Journal of Applied Phycology.

[11]  E. Rabinowitch,et al.  Photosynthesis and Related Processes , 1946 .

[12]  Yasushi Hashimoto,et al.  VEGETABLE GROWTH AS AFFECTED BY ON-OFF LIGHT INTENSITY DEVELOPED FOR VEGETABLE FACTORY , 1988 .

[13]  W. Giger,et al.  Re-evaluation of published data on the relative photosynthetic efficiency of intermittent and continuous light. , 1980 .

[14]  Eugene J. Rablnowitch.  Photosynthesis And Related Process , 1945 .