Symptoms
Rhizoctonia infection typically occurs close to the soil surface. Symptoms begin as reddish-brown sunken lesions on the hypocotyl or stem that remain firm and dry at the soil line. Over time, the stem or hypocotyl decomposes and eventually resembles a thread or wire, indicative by the common name, wirestem. The pinched stem prevents the plant from accessing water and nutrients, resulting in stunted, yellow, necrotic plants that fail to thrive, are easily blown or knocked over and, in severe cases, plant death. Rhizoctonia infections are the most aggressive from 24–30°C under various soil moisture conditions. Emergence to 8-leaf infected seedlings may wilt and die as lesions grow and rot through the hypocotyl. If plants survive, they will remain stunted and are less productive.
Later-season symptoms may be difficult to distinguish from a Fusarium infection.
Resources
Current resources focus on something other than Rhizoctonia; however, the following resources provide general guidance on root rot pathogens.
Aphanomyces Root Rot in Pulse Crops | Saskatchewan Pulse Growers
Aphanomyces Root Rot in Peas and Lentils in Western Canada, 2019 | Alberta Pulse Growers
Root Rot in Peas and Lentils in Western Canada, 2016 | Manitoba Pulse & Soybean Growers
Research Keeping Up the Fight Against Aphanomyces | Alberta Pulse Growers
