HPIPM:Verticillium Wilt

Author: Ned Tisserat and Gary Franc"

Taxonomy

Domain	Eukarya
Kingdom	Fungi
Phylum	Ascomycota
Subphylum	Pezizomycotina
Class	Sordariomycetes
Subclass	Hypocreomycetidae
Order	Glomerellales
Family	Plectosphaerellaceae
Genus	Verticillium

Scientific Name

Verticillium dahliae

Scientific Name Synonyms

Verticillium tracheiphilum

Verticillium ovatum

Common Name

Verticillium wilt

Cause

Verticillium albo-atrum

Occurrence

Verticillium wilt is widespread in the High Plains but has largely been controlled by the use of resistant varieties.

Key Symptoms

• Stunting and wilting,
• Leaves on upper stem may be slightly twisted with a pinkish tinge
• Leaflets may develop v-shaped chlorosis
• Internal root tissue turns yellow-brown, although this is not always a reliable symptom
• Plants should be sent to laboratory for confirmation
• Plants may die in mid-summer

Pathogen

This fungus persists in the soil for years. It can also be carried internally and externally on seed.

Management Approaches

Use resistant varieties. See the following sources for varietal information:

• University of Wisconsin forage pages http://www.uwex.edu/ces/forage/pubs/varinfo.htm
• University of Wyoming Alfalfa Disease Management Publication B1136 http://ces.uwyo.edu/PUBS/B-1136.pdf
• Alfalfa should follow corn or small grain in a rotational sequence. Never follow alfalfa with alfalfa.
• Avoid injury to crowns and roots including cultivation and excessive traffic

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.