Coffee rust (141)

Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens & Weeds

Coffee rust (141)

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Photo 1. Young yellowish leaf spots, 3-5 mm diameter, of coffee rust, Hemileia vastatrix, on the upper surface of a coffee leaf mostly between the veins. Some of the spots are starting to merge.

Photo 2. Yellow-orange spots on the underside of a coffee leaf caused by coffee rust, Hemileia vastatrix. The spots have started to form powdery spores.

Photo 3. Close-up of the powdery spore masses of coffee rust, Hemileia vastatrix, on the underside of a coffee leaf at a late stage of infection when many of the spots have merged.

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.

Common Name

Coffee leaf rust

Scientific Name

Hemileia vastatrix

AUTHOR Grahame Jackson
Information (and Photos 1&2) from Gerlach WWP (1988) Plant diseases of Western Samoa. Samoan German Crop Protection Project, Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) Gmbh, Germany; and CABI (2020) Hemileia vastatrix (coffee leaf rust). Crop Protection Compendium. (https://www.cabi.org/cpc/datasheet/26865); and Arneson PA (2000) Coffee rust. The Plant Health Instructor. (https://www.apsnet.org/edcenter/disandpath/fungalbasidio/pdlessons/Pages/CoffeeRust.aspx); and from Hemileia vastatrix. Wikipedia. (https://en.wikipedia.org/wiki/Hemileia_vastatrix). Photo 3 Kohler F, et al. (1997) Diseases of cultivated crops in Pacific Island countries. South Pacific Commission. Pirie Printers Pty Limited, Canberra, Australia.

Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community.

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