Phytophthora Root Rot of Alfalfa

Published 2011

Phytophthora root rot is a major cause of seedling death in newly established alfalfa and causes a progressive decline of established stands in Nebraska. This disease is caused by the fungus Phytophthora megasperma f. sp. medicaginis and occurs in most of the alfalfa producing areas in North America.

Phytophthora root rot is most damaging on susceptible cultivars and where the soil remains wet due to high clay content (heavy, fine-textured soils), poor drainage, over-irrigation or a combination of these. Phytophthora causes damping-off of seedlings, root rot, and rot of lower stems. It also weakens mature plants, making, them more susceptible to injury during severe winters and could eventually result in plant death.

Publication Details


Stephen N. Wegulo

Bruce E. Anderson


Plant Diseases

Publication Date April 25, 2011
Last Revision Date April 25, 2011
Language English


Series NebGuide