Abstract
The concentration of dissolved oxygen in a culture solution is one of the most important environmental factors affecting the growth of the tops and roots of plants under hydroponic culture. In particular, the roots of tomatos readily absorb oxygen in the solution, and are thus sensitive to the concentration of dissolved oxygen. Thus, the effects of dissolved oxygen concentration on the morphology and growth of roots, water uptake rate and nutrient uptake were investigated. In hydroponic culture, the supply of dissolved oxygen is essential. Previously, we reported that supersaturation of dissolved oxygen in culture solution promoted the uptake of phosphate. In the present study, we found that supersaturation of dissolved oxygen in culture solution low in nitrogen and phosphate led to an increase in plant height, fresh weight of stems and leaves and root weight. It also increased the phosphorus concentration in the sap, stems, leaves and fruits of tomato plants.
