PROBLEM TO BE SOLVED: To suppress alteration while reducing cost of chemical-free fumigation.SOLUTION: A mixture gas is composed of a mixture of superheated steam (21) generated by heating saturated steam by a heat source (4) and non-chemical gas composed of at least one of air, carbon dioxide, and nitrogen gas and the mixture ratio is controlled. A chemical-free fumigation method using superheated steam is characterized by conducting fumigation treatment of a plant (22) to be fumigated using the mixture gas at a dew-point temperature based on a preset fumigation temperature for the plant (22) to be fumigated.COPYRIGHT: (C)2013,JPO&INPIT【課題】無薬剤燻蒸においてコストを低減しつつ、変質を抑えること。【解決手段】飽和水蒸気を熱源(4)で加熱して発生される過熱水蒸気(21)と、空気、炭酸ガスおよび窒素ガスの少なくとも1つからなる非薬剤性の気体とが混合され且つ混合比が制御された混合気体であって、燻蒸対象の植物(22)に対して予め設定された燻蒸温度に基づいた露点温度の前記混合気体を使用して、前記燻蒸対象の植物(22)の燻蒸処理を行うことを特徴とする過熱水蒸気を用いた無薬剤燻蒸方法。【選択図】図1
