Abstract
The objective of this study was to clarify the influence of dissolved oxygen (DO value) on the growth of plants to control the DO value with an aeration nozzle in solution cultuse systems. Tomato seedlings were grown in different DO value conditions in a range of 15〜45%(1.2〜3.8ppm). Changes in the fresh weight of the plant, stem diameter, the leaf area and the transpiration rate (water flux of the plant) were measured with various instruments, including a laser beam type displacement sensor, a heat balance sensor and a color video camera. From the experimental results, it was clear that under the same environmental conditions, a higher DO value content in the solution would result in a faster transpiration rate thus producing quicker growth, although a value rate below 15% would stop the plants growth. Consequently, it show that the growth of a plant could be controlled by the density of the DO value.
