DISEASES OF ALFALFA -VERTICILLIUM WILT

Verticillium wilt is commonly managed through use of wilt resistant varieties. A comparison of alfalfa varieties with differing levels of Verticillium wilt resistance is shown in this photo. A variety with a high level of resistance to Verticillium wilt is shown on the right (see white arrow) and a variety with little resistance is shown on the left (black arrow). Verticillium wilt-resistant varieties appear to delay the onset of symptom development and provide some increased stand longevity, but do not appear to prevent death in the long run.

In addition to selection of an appropriate alfalfa variety, selection of a drier site for production of alfalfa may help limit the impact of Verticillium wilt. As with many soil-borne pathogens, Verticillium albo-atrum tends to be more active under wet soil conditions.