Harry A. J. Hoitink and Steven T. Nameth, Professors, Department of Plant Pathology, Ohio Agricultural Research and Development Center, The Ohio State University; and James C. Locke, Research Plant Pathologist, U.S. Department of Agriculture, Agricultural Research Service, Application Technology Research Unit, Wooster, Ohio.
Root Rot Fungicides
Chipco Aliette and Subdue MAXX are examples of fungicides that are very effective when applied as drench treatments for control of Phytophthora root rots. Follow the label for each crop.
Resistant Varieties
A large number of rhododendrons and azaleas have been screened for resistance to root rot and dieback. Varieties and species somewhat resistant to root rot were found. However, this resistance can be broken down under conditions of severe drought, high salinity, or other stress conditions. Furthermore, the most popular varieties are highly susceptible. Resistance to these diseases therefore typically is not a realistic control option.