Jerry from La Vernia, Texas writes
Subdue Maxx is not labeled specifically for Hypoxylon Canker Fungus. According to this extension article from UMN, "there are no fungicides that prevent or cure Hypoxylon canker." However, proper management practices can significantly reduce problems that may possibly occur. Generally, avoiding tree stress and maintaining an overall healthy tree is the best way of avoiding the canker. Please contact County Extension Office for the Master Gardener’s recommendation on what methods they’ve found to be a successful treatment.
Answer last updated on: 09/07/2021
