Ginger (Zingiber officinale Rosc.) is an important cash crop which is widely planted in China, especially in Shangdong district. Ginger soft rot, caused by the soilborne pathogen Pythium myriotylum, is one of the most devastating diseases of ginger . The first symptoms of infected ginger are yellow leaves and collapsed shoots; below ground, water-soaked lesions appear on the developing rhizome . Under suitable conditions the rhizome rots rapidly and an infested field can be destroyed by the pathogen within a week .