DISEASES OF ALFALFA - ROOT ROTS

In addition to causing seedling stand problems, Phytophthora medicaginis and Aphanomyces euteiches can also cause root rot problems in older plants. Once again, P. medicaginis tends to be the more aggressive of the two pathogens. It invades the taproot, causing lesions (diseased areas) on the main root system and subsequent disintegration of root tissue (see black arrows in the photo). This pathogen can eventually kill the alfalfa plant.