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The objective of this study was to detect the plant stoma response under the lighting conditions of continuous and 1 to 15 minutes of lighting. In this study, a real-time measurement system was developed to observe a living plant stoma continuously for a long period in a growth chamber, using a microscope and a color TV camera. A video recording system was adopted to obtain details of stoma movement, and images were captured every 30 seconds.

From the experimental results, it was observed that the stoma opened slowly 5 minutes after the lights were turned on, and then opened rapidly until it reached the maximum pore size. In guard cells, light stimulus activates a proton pump, the resulting hyper polarization of the plasma membrane opens voltage-sensitive K+ channels, and then the water entering the guard cells opens the stoma after the K+ ions have entered. This process may cause 5 minutes of delay, and delay was also observed after the light was turned off. 10 minutes of lighting opened the stoma to the maximum size.

For better utilization of lighting, it was suggested to turn a light on 10 minutes at 30 minuets before the lighting period to open stomata widely at the beginning of the lighting period, so then plants can start the photosynthesis immediately without any effect of the response of stomata opening. To prove this, carbon dioxide absorptions were measured and as a result 8 % of the photosynthesis benefit was given with these on/off controls.