Potato mop-top virus

PMTV

Symptoms

• Yellow blotches and chevrons
• Shortening of internodes leading to ‘mop-top’ appearance
• Not all stems are affected
• Varietal differences in symptom expression
• Tuber symptoms of brown arcs (spraing) in susceptible varieties

Infection and spread

• The viral vector is the powdery scab fungus
• Fungal spores can remain viable in the soil for several years

Possible confusion with

• Tobacco rattle virus (TRV)