PROBLEM TO BE SOLVED: To provide a watering valve easily attached to an empty PET bottle, smoothly discharging water and facilitated in operation: to provide a watering device using the valve: and to provide a plant cultivation device.SOLUTION: The watering valve 12 includes: a cylindrical part 13 vertically extended a lotus root-shaped block part 14 which blocks the inside of the cylindrical part, the lower surface of which is slanted and which includes at least a water discharge passage 14a and an air-introducing passage 14b a valve 15 biased in a direction where the top end opening of the cylindrical part is blocked and a valve rod 16 for releasing a lid from blocking the top end opening of the cylindrical part by setting a water supply container to a water passage 22.COPYRIGHT: (C)2010,JPO&INPIT【課題】本発明は空のペットボトルに容易に取り付けることができ、水の排出がスムーズで、取り扱いが容易である給水装置の給水ならびにそれを用いた給水装置および植物栽培装置を提供する。【解決手段】上下に延びる筒状部13と、その筒状部の内部を塞ぎ、下面が傾斜し、少なくとも水排出路14aと空気導入路14bを備えたレンコン状のブロック部14と、前記筒状部の上端開口を塞ぐ方向に付勢されている弁体15と、前記水供給容器を水路22に設置することにより、前記蓋が筒状部の上端開口を塞ぐのを解除する弁棒16とを備えている給水弁12。【選択図】図1
