Rhizoctonia on a rhododendron. Photo credit: Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services. Bugwood.org
Rhizoctonia often infects the base of the plant causing stem lesions, damping off and root and crown rots. As a soil-borne disease, it is spread by contact with contaminated plant material and media. Therefore, growers should be scouting their plants for the disease and throw out infected plants immediately to prevent the spread of the pathogen. To prevent spread, do not overwater plants and reduce humidity in the greenhouse. As with all diseases, stressed plants will be more susceptible to infections.
To prevent spread, Michigan State University Extension recommends the following fungicides:
- Fludioxonil, (Medallion)
- Pentachloronitrobenzene (Terraclor 400)
- Polyoxin D zinc salt (Affirm WDG)
- Pyraclostrobin + Boscalid (Pageant Intrinsic)
- Thiophanate-methyl (Cleary’s 3336/OHP 6672)
- Captan (captan; note 48-hr REI)
- Azoxystrobin (Heritage 50WG)
Rhizoctonia on Chinese cabbage (left) and Madagascar periwinkle seedlings (right). Photo credits: Gerald Holmes. California Polytechnic State University. Bugwood.org (left); Mary Ann Hansen, Virginia Polytechnic Institute and State University. Bugwood.org (right)
This fungal pathogen can be long-lived because it can produce sclerotia, a long-term survival structure. Therefore, growers who had crops infected with Rhizoctonia should be diligent in sanitizing and cleaning all areas where the pathogen was present after this growing season.
For more information, check out the report on Rhizoctonia solani from MSU Diagnostics Services.
Note: Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.
This article was published by Michigan State University Extension. For more information, visit http://www.msue.msu.edu. To have a digest of information delivered straight to your email inbox, visit http://bit.ly/MSUENews. To contact an expert in your area, visit http://expert.msue.msu.edu, or call +1 888-MSUE4MI (+1 888-678-3464).
