Affected leaves collapse and turn mushy and the dusty gray to tan spores of the pathogen can be easily seen with a 10 x hand lens. Many plants other than Hoya spp. Examples of other hosts include lipstick vine, African violet, English ivy and the majority of flowering crops such as Lisianthus , marigold, and roses. This is probably due to the waxy nature of the plant which retards wilting even when all roots are rotted. Lesions on the stems are usually brown to black and can be mushy or dry.
Roots are gray to black and can also be mushy or dry.
If plants are infected with Rhizoctonia sp., leaves can also be infected and the weblike red-brown mycelium of the pathogen can spread across the potting medium surface and leaves. Reduce water applications to plants suspected of stem or root rot disease and be sure to start with fresh potting medium, pots and pathogen-free cuttings for each crop. Depending upon the cause of the stem or root rot, a fungicide may be chosen for control. Since symptoms caused by these organisms are similar and fungicides used for their control differ, the exact organisms involved in each disease must be accurately determined. Pythium, Phytophthora spp.