Aphanomyces exist in the soil in a resting form called an oospore. When soil conditions reach saturation and host plant roots are present, the oospores are signalled to begin germination.
Zoospores released during germination are typically responsible for the most severe infections. Both oospores and zoospores can infect the host plant roots. Once infected, fungal-like hyphae grow throughout the plant roots, eventually forming a new oospore, resulting in decayed and dying plant roots and stems. The newly formed oospores will be fertilized and remain in the dead host plant tissue or the soil over time. Oospores can be viable in the soil for 10–20+ years.
Resources
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
