Phytophthora
/fy-TOFF-thor-uh/🦠 Diseases●●● Advanced
Also known as: water mould, root rot organism
A genus of oomycetes (not true fungi) that are among the most destructive plant pathogens worldwide. Phytophthora species cause root rot, crown rot, stem cankers, and foliar blight in a vast range of hosts. P. infestans caused the Irish potato famine; P. ramorum causes sudden oak death. These organisms thrive in wet conditions and poorly drained soils. Management focuses on improving drainage, avoiding overwatering, and using resistant rootstocks.
Etymology
Greek phyton (plant) + phthora (destruction)
Example
“Phytophthora root rot is the most common cause of death in rhododendrons planted in heavy, poorly drained soil.”