Pacific Pests, Pathogens and Weeds

View full fact sheet

Summary

• Worldwide distribution. On arabica and robusta coffee. An important disease.
• Spots, 2-3 mm, expanding to 15 mm, with yellow-orange powdery blotches on underside. Later, spots on top turn brown with yellow halos. Leaves may fall and shoots dieback. Over-bearing dieback may occur if rust epidemics occurs on high-yielding trees. Food reserves from the tree are diverted to the berries and stem dieback results.
• Spores spread by wind and insects, but need water to germinate. Possibly, new strain in Central America.
• Cultural control: critical factors are: spacing; soil nutrition; shade; resistant varieties (e.g., Catimor).
• Chemical control: copper (protectant); triazoles (systemic). Usually, not needed above 1700 m.