Scouting for diseases: Veronica rust
Editor’s note: This article is from the archives of the MSU Crop Advisory Team
Alerts. Check the label of any pesticide referenced to ensure your use is
included.
Pathogen: Puccinia veronicae-longifoliae. (view images)
Hosts: Veronica longifolia and V. spicata.
Symptoms: Bronze, purplish overcast on the upper surface of
infected foliage. Raised, reddish brown pustules on the underside of
foliage. When disease is severe, significant foliar blighting occurs.
Spread: This disease was unintentionally introduced to Michigan
in 2004 and was found again in 2005. The disease occurred on
field-grown Veronica. To date it has been a problem in very few
nurseries. Long-distance disease spread is thought to occur when
infected propagation material is moved. Spores, produced on foliage, are
carried by wind currents.
Management: Carefully inspect incoming plant material for signs
of rust; pay particular attention to material that originated offshore.
Plants with rust pustules or other disease symptoms should be
destroyed. Fungicide applications are needed for disease control in some
situations. Resistance development is a concern – follow recommended
fungicide resistance management strategies.