PROBLEM TO BE SOLVED: To make it possible to easily perform cultivation by exposure to coldness in a plant cultivation system for performing hydroponics.SOLUTION: A plant cultivation system is provided with a nutritious liquid temperature adjusting part (40) which adjusts a temperature (T2) of a nutritious liquid (L) in a second nutritious liquid tank (30) to a temperature (T3) for performing cultivation by exposure to coldness to increase the sugar content in an edible part of a plant (P). It is also provided with a cultivation mode switching part (50) which switches between a first cultivation mode (M1) for giving the plant (P) a nutritious liquid (L) in a first nutritious liquid tank (20) and a second cultivation mode (M2) for giving the plant (P) the nutritious liquid (L) in the second nutritious liquid tank (30) for a predetermined period before the harvest of the plant (P).SELECTED DRAWING: Figure 1【課題】水耕栽培を行う植物栽培システムにおいて、容易に寒締めを行えるようにする。【解決手段】第２養液槽（30）の養液（L）の温度（T2）を、植物（P）の可食部に含まれる糖度の上昇を図る寒締めを行う温度（T3）に調整する養液温度調整部（40）を設ける。第１養液槽（20）の養液（L）を植物（P）に与える第１栽培モード（M1）と、該植物（P）の収穫前の所定期間に第２養液槽（30）の養液（L）を植物（P）に与える第２栽培モード（M2）とを切り替える栽培モード切換部（50）を設ける。【選択図】図１
