Causal Agents

Rhizoctonia solani

Hosts

Large host range of herbaceous plants. Some hosts include:

Azalea, Begonia, Holly, Impatiens, Philodendron, Poinsettia

Symptoms & Signs

Roots of infected plants become brown and rotted. Rotted roots will disintegrate when handled. As the root system becomes compromised, plants will become wilted, chlorotic, and will appear stunted compared to healthy plants. Brown sunken cankers may form on the plant stem at the soil surface…

When Does it Happen?

Rhizoctonia solani is a soilborne fungus that produces survival structures, called sclerotia, that allow it to persist in the soil. Warm to hot temperatures are favorable for Rhizoctonia growth. Closely spaced and stressed plants are both more susceptible to infection…

Cultural Management

Proper sanitation practices are crucial to preventing the spread of Rhizoctonia. Since Rhizoctonia is soilborne, never reuse growing media or containers from infected plants. Remove and discard all infected plant material. Promote airflow with proper spacing between plants. Alleviate plant stress. Reduce humidity in the greenhouse.

Chemical Management

Apply fungicides as a soil drench to deliver the product to the location of the fungus. Not all fungicides labeled for use against Rhizoctonia may be labelled for use as a soil drench. Always check product labels for application uses. Curative fungicide applications are not as effective as preventative…