A plant weight measurement instrument comprises a top disk, a bottom disk, a plant holder, and a load cell. The top disk and bottom disk are separated, and the plant holder is assembled between the top disk and the bottom disk. There are two openings at the upper portion and the lower portion of plant holder respectively, a plant can grow toward the two openings in the pant holder, and the load cell is fixed with the top disk. The load cell can automatically measure the total weight of the plant. This invention further comprises a method for measuring plant weight.水耕栽培作物的重量量測裝置包括一上拖盤、一下拖盤、一植物生長槽、及一重量感測器。該上拖盤與該下拖盤相互間隔,而該植物生長槽具有一上開口及一下開口。該植物生長槽組接於該上拖盤與下拖盤之間,水耕栽培作物可於植物生長槽內朝向該上開口與下開口進行生長,而該重量感測器固接於該上拖盤,該重量感測器用以自動地量測出整株的該水耕栽培作物的重量。本發明更包括一水耕栽培作物的重量量測方法100‧‧‧重量量測裝置101‧‧‧支撐架102‧‧‧上拖盤102A‧‧‧上表面104‧‧‧下拖盤106‧‧‧植物生長槽108‧‧‧重量感測器110‧‧‧使用者介面124‧‧‧支撐件126‧‧‧固定件136‧‧‧凸緣200‧‧‧養液平台300‧‧‧水耕栽培作物
