Coffee rust

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Coffee rust
Hemileia vastatrix uredinial pustules.png

Coffee rust ( Hemileia vastatrix )

Systematics
Subdivision : Pucciniomycotina
Class : Pucciniomycetes
Order : Rust mushrooms (Pucciniales)
without rank: Incertae sedis
Genre : Hemileia
Type : Coffee rust
Scientific name
Hemileia vastatrix
Berk. & Broome

The coffee rust ( Hemileia vastatrix ) is a rust fungus , the coffee plants affects and triggers the disease the same name. It is the most economically important disease in this culture.

Economical meaning

Originally, coffee rust ( English coffee leaf rust, Spanish roya del cafeto, port. Ferrugem do café) with its gene pool was restricted to Central and East Africa and from 1868 to the Old World (Africa, Asia and Australia) before it was first used in 1903 was observed in Puerto Rico . In 1970 the fungal disease spread epidemically to Brazilian coffee plantations from Minas Gerais to the intensive crops in Paraná and Santa Catarina , and from there via Colombia to Central America, where it caused great economic damage. The damage can affect 30% to 80% of the plants or even lead to complete crop failures.

Occurrence of coffee rust in individual coffee-growing areas
place Publishing year
Ceylon 1868
India 1869
Philippines 1871
Sumatra 1876
Java 1879
Borneo 1890
West Africa 1954
Brazil 1970

biology

Coffee rust belongs to the order of mushrooms . The host plants for coffee rust are Coffea arabica , Coffea liberica and sometimes gardenias . Coffea canephora is only attacked by a few rust races and therefore serves as genetic material for resistance breeding. Characteristic of the fungus is the morphology of its spores, by which it can be clearly identified.

The haplont of the coffee rust has not yet been identified. The orange uredospore beds are found on the underside of the leaf. The spores of the fungus are formed in the stem hyphae of the plant and are released into the ambient air via the stroma. The resistance to Hemileia vastatrix can vary in leaves at different stages of development; very young and older leaves are particularly at risk.

The fungus survives dry periods in the infected plant organs and can sporulate immediately after rain events and spread to other plants. At the beginning of the rainy season, major epidemics can occur, as the spores spread quickly due to the impact of the raindrops. Insects can also transmit the spores. The temperature optimum for Hemileia vastatrix is between 21 and 25 ° C. The spores are viable for 2–15 days and can be transported over long distances in infected seeds. Of the total of 40 mushroom breeds, breed II proves to be particularly infectious.

Symptoms

Infested leaf

Coffee rust attacks Arabica varieties and, through colonization of the leaves, leads to the shrubs shedding leaves. Overall, the vegetative growth of the plants is severely weakened and entire stands can die in the event of mass infestation. Circular white to yellowish spots of various sizes form on the leaves, some with a uredospore coating. Affected leaves become necrotic and die off after a short time.

Combat

For over a century, strict plant quarantine measures prevented coffee rust from being carried over from the Old World to Central and South American plantations. There has been speculation about the spread, possibly through trade winds, infected coffee beans or spore growth on host plants such as gardenias. When the barrier of the Atlantic Ocean was bridged in the 1970s, the fungus spread rapidly through the air to all Brazilian plantations. When Hemileia vastatrix spread from south to north across the Central American land bridge, devastating epidemics quickly developed. Sometimes there were total failures and the infected plants had to be completely destroyed.

Growing coffee with and without shade trees offers advantages. Cultures without shade trees can be processed more easily with fungicides in the event of acute infestation. Coffee with shade trees reduces dew formation on the coffee plants and thus a greater spread. The amount of nitrogen fertilization can significantly influence the occurrence of coffee rust. The hyperparasite Verticillium hemileiae can be used in the biological disease control of coffee rust . The effect of these mycoparasites on coffee rust was described in 2002 in Mexican coffee cultures.

Fungicides

Were used fungicides with triadimefon as an active ingredient or various copper compounds. Ideally, the application should take place three weeks before the start of the rainy season. For Kenyan locations, 6.6 to 7.5 kg Cu ​​/ ha are used. Other effective fungicidal active ingredients are fentin hydroxide (2.5 kg / ha) or dithianon (3.3 kg / ha) lid in oily suspension. Maneb is mainly used on Brazilian coffee plantations . For smallholders, the use of biocides is usually out of the question due to the high costs.

Resistance breeding

The Coffee Rust Research Center in Oeiras / Portugal has been researching resistance breeding to coffee rust since the 1970s. Coffee rust is manifested by a large number of physiological races that have inflicted severe economic damage on large-scale coffee cultivation in India, Kenya and Brazil. The “Caturra” variety was particularly sensitive to coffee rust, so that its cultivation in Colombia had to be severely restricted. "Hybrido de Timor" turned out to be a variety that was not attacked by most rust strains. So far, nine genotypes have been identified that have been shown to be resistant to coffee rust. In Colombia, Cenicafé in Chinchiná - Manizales , Colombia , has been commissioned to supply local fungus-resistant coffees. Resistance breeding is facing new challenges due to the loss of the genetic material of many wild types of Coffea and the constantly adapting mushroom breeds. The Ethiopia's Institute of Biodiversity Conservation and Research is keeping the remaining genotypes and the Ethiopian government has spoken out in favor of a ban on the export of coffee plants and beans.

literature

  • Sigmund Rehm: Handbook of Agriculture and Food in the Developing Countries: Volume 4: Special crop production in the tropics and subtropics . Göttingen 1989, ISBN 3-8001-3072-6 .
  • Jürgen Kranz, Heinz Schmutterer, Werner Koch: Enfermedades, Plagas y Malezas de los Cultivos Tropicales. Paul Parey Publishing House, Berlin / Hamburg 1982, ISBN 3-489-68826-0 .
  • FJ Nutman, FM Roberts: Coffee Leaf Rust. In: Pans. No. 16, 1970, pp. 606-624.
  • Eugenio Schieber: Economic Impact of Coffee Rust in Latin America. In: Annual Review of Phytopathology. 1972, Vol. 10, pp. 491-510.
  • Eugenio Schieber: Present Status of Coffee Rust in South America. In: Annual Review of Phytopathology. 1975, Vol. 13, pp. 375-382.
  • Ajjamada C. Kushalappa, Albertus B. Eskes: Coffee Rust - Epidemiology, Resistance and Management. CRC Press, 1989, ISBN 0-8493-6899-5 .
  • Günther M. Hoffmann, Franz Nienhaus, Fritz Schönbeck, Heinrich C. Weltzien, Hubert Wilbert: Textbook of Phytomedicine. Paul Parey Verlag, Berlin / Hamburg 1985, ISBN 3-489-60626-4 .

Web links

Commons : Coffee rust  - collection of images, videos and audio files

Individual references, comments

  1. ^ Eugenio Schieber: Economic Impact of Coffee Rust in Latin America. In: Annual Review of Phytopathology. 1972.
  2. ^ A b Günther M. Hoffmann, Franz Nienhaus, Fritz Schönbeck, Heinrich C. Weltzien, Hubert Wilbert: Textbook of Phytomedicine. Paul Parey Verlag, Berlin / Hamburg 1985, p. 271.
  3. ↑ Jürgen Kranz, Heinz Schmutterer, Werner Koch: Enfermedades, Plagas y Malezas de los Cultivos Tropicales. Paul Parey Publishing House, Berlin / Hamburg 1982, p. 164.
  4. ^ Sigmund Rehm: Handbook of Agriculture and Food in Developing Countries. Volume 4: Special crop production in the tropics and subtropics. Göttingen 1989, p. 433.
  5. ^ Günther M. Hoffmann, Franz Nienhaus, Fritz Schönbeck, Heinrich C. Weltzien, Hubert Wilbert: Textbook of Phytomedicine. Paul Parey Verlag, Berlin / Hamburg 1985, p. 88.
  6. ^ Günther M. Hoffmann, Franz Nienhaus, Fritz Schönbeck, Heinrich C. Weltzien, Hubert Wilbert: Textbook of Phytomedicine. Paul Parey Verlag, Berlin / Hamburg 1985, p. 250.
  7. ^ Sigmund Rehm: Handbook of Agriculture and Food in Developing Countries. Volume 4: Special crop production in the tropics and subtropics. Göttingen 1989, p. 434.
  8. ↑ a b Jürgen Kranz, Heinz Schmutterer, Werner Koch: Enfermedades, Plagas y Malezas de los Cultivos Tropicales. Paul Parey Publishing House, Berlin / Hamburg 1982, p. 165.
  9. ^ Günther M. Hoffmann, Franz Nienhaus, Fritz Schönbeck, Heinrich C. Weltzien, Hubert Wilbert: Textbook of Phytomedicine, Paul Parey Verlag. Berlin / Hamburg 1985, p. 294.
  10. ^ Gloria Carrión, Victor Rico-Gray: Mycoparasites on the coffee rust in Mexico. Fungal Diversity, 2002 ( full text ; PDF; 6.3 MB)
  11. ^ Website of the Coffee Rust Research Center (English / Portuguese), accessed on February 4, 2010.
  12. ^ Sigmund Rehm: Handbook of Agriculture and Food in Developing Countries. Volume 4: Special crop production in the tropics and subtropics. Göttingen 1989, p. 427.
  13. ↑ cenicafe.org
  14. ↑ http://www.apsnet.org/Education/lessonsPlantPath/Coffeerust/mngmnt.htm ( Memento from June 16, 2010 in the Internet Archive )