PROBLEM TO BE SOLVED: To improve photo synthesis efficiency of plants in a method for cultivating plants using artificial illumination lamps.SOLUTION: An illumination covering material is made of a cylindrical member which is formed by bonding end parts of a rolled resin film to each other or bonding end parts of two resin films to each other, and the inside of the cylinder is made a housing space for a straight tube type illumination lamp. In the illumination covering material, a part of or all of the resin film is formed of a wavelength conversion film containing fluorescent dye that absorbs light having wavelength of 400 to 600 nm and emits fluorescent light having wavelength of 600 to 700 nm.SELECTED DRAWING: Figure 2【課題】 人工照明灯を用いた植物の栽培方法における植物の光合成効率を改良する。【解決手段】 樹脂フィルムを丸めた端部同士を接着、あるいは二枚の樹脂フィルムの端部同士を接着して形成した筒状の部材からなり、その筒状内部を直管型照明灯の収容空間とする照明被覆材であって、前記樹脂フィルムの一部又は全部が、波長４００～６００ｎｍの光を吸収して波長６００～７００ｎｍの蛍光を発光する蛍光染料を含有する波長変換フィルムからなることを特徴とする照明被覆材。【選択図】 図２
