The effects of twelve metal ions on mycelial growth and sclerotial formation of Rhizoctonia solani AG 1 IA were studied. According to the concentration affecting mycelial growth and sclerotial formation, these twelve metal ions could be divided into three groups: (1) The inhibiting concentration is the highest. There was still a little mycelial growth and sclerotial formation at 2 500 μg/mL. Mg 2+ , Ba 2+ , Ca 2+ and Mn 2+ belong to this group. Worthy of mention is that Mg 2+ p...