Alfalfa mosaic (AMV) (Alfamovirus Alfalfa Mosaic Virus) is a viral pathogen of alfalfas and clovers. It was first detected in Maryland in 1984.
Transmitted mechanically or by aphids and seeds. Symptoms include bright yellow splotches on the leaves and necrotic rings on and spots on fruit. Infection usually leads to plant death. This virus can infect over 600 species of plants, although risk of infection is low unless planted next to alfalfa fields.