PROBLEM TO BE SOLVED: To provide a hydroponic apparatus capable of achieving both of suppression of root rot of plants in high temperature environment and promotion of photosynthesis of plants using the high temperature environment.SOLUTION: A hydroponic apparatus 100 comprises: a liquid flow path/pooling unit 10 in which water or nutritious liquid 3, into which roots 2 of plants 1 are immersed, flows or is pooled an oxygen concentration adjusting unit 60 which adjusts oxygen concentration in the water or nutritious liquid 3 temperature measurement units 30, 40 which measure the temperature of the plant 1 or a predetermined position near the plant 1 and a control unit 50 which controls the oxygen concentration adjusting unit 60 so as to increase the oxygen concentration in the water or nutritious liquid 3 when the temperature at the predetermined position measured by the temperature measurement units 30, 40 reaches the highest growth limit temperature of the plant 1 or a temperature corresponding to the highest growth limit temperature or higher.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】高温環境における植物の根腐れの抑制と高温環境を利用した植物の光合成の促進との双方を実現することができる水耕栽培装置を提供する。【解決手段】水耕栽培装置100は、植物1の根2が浸される水または養液3が流れるかまたは貯留される液体流路/貯留部10と、水または養液3中の酸素濃度を調整する酸素濃度調整部60と、植物1または植物1の周辺の所定の位置の温度を測定する温度測定部30,40と、温度測定部30,40によって測定された所定の位置の温度が植物1の生育最高限界温度または生育最高限界温度に対応する温度以上の温度になった場合に、水または養液3中の酸素濃度を増加させるように、酸素濃度調整部60を制御する制御部50と、を備えている。【選択図】図1
