Scouting for diseases: Veronica rust
Editor’s note: This article is from the archives of the MSU Crop Advisory Team
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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.