{ "id": "coffee-berry-disease", "url": "https://coffearium.org/entries/coffee-berry-disease/", "license": "CC-BY-4.0", "title": "Coffee berry disease", "summary": "The fungal disease that attacks green arabica berries on the tree. How Colletotrichum kahawae infects, why wet highlands in Africa suffer most, how resistant varieties were bred, and why other regions guard against it.", "domain": "farm-management", "kind": "Disease", "stage": "farm", "topics": [ "history", "science" ], "topicSections": {}, "lang": "en", "status": "verified", "reviewer": "Coffearium verification pass", "lastVerified": "2026-10-16T00:00:00.000Z", "updated": "2026-10-16T00:00:00.000Z", "added": "2026-10-16T00:00:00.000Z", "brief": [ "Coffee berry disease (CBD) is caused by the fungus Colletotrichum kahawae. It attacks flowers and fruit of arabica coffee and was first reported in Kenya in 1922.1,2", "Expanding green berries are the most susceptible stage, about 4–14 weeks after flowering.2,16", "Rain spreads the spores over short distances, and the disease is most severe at higher altitudes in Africa.2,3,8", "Without control, losses of up to 70–80% of the crop are reported.1,2", "As of October 2026, the disease is known from Africa and, since a 2024 report, from a restricted area of China.4,6" ], "quickFacts": [ { "label": "Pathogen", "value": "Colletotrichum kahawae (older name in the literature C. coffeanum)" }, { "label": "First report", "value": "Kenya, 1922" }, { "label": "Most susceptible", "value": "Expanding green berries, about 4–14 weeks after flowering" }, { "label": "Spread", "value": "Rain water, over short distances" }, { "label": "Resistance genes", "value": "R and k (Rume Sudan), k (K7), T (Timor Hybrid; Ck-1)" }, { "label": "Losses without control", "value": "Up to 70–80%" }, { "label": "Known range (Oct 2026)", "value": "14 African countries (EPPO); restricted in China (EPPO, 2024 data)" } ], "aka": [ "CBD", "Colletotrichum kahawae", "Coffee berry anthracnose" ], "linkTerms": [ "coffee berry disease", "Colletotrichum kahawae", "kahawae", "scab lesion", "active lesion" ], "related": [ "coffee-leaf-rust", "arabica-varieties", "ethiopian-landraces", "site-selection-and-climate", "harvesting-and-sorting", "coffea-arabica", "coffea-canephora", "coffee-berry-borer" ], "contested": [ "Presence outside Africa: a 2024 report identified C. kahawae on Coffea liberica in Pu’er, Yunnan, China, by morphology, pathogenicity tests and multi-gene sequencing6, and EPPO lists China as “present, restricted distribution” on information dated 20244; a 2025 survey of coffee anthracnose in Yunnan and Hainan, based on samples collected in 2019, states that C. kahawae has not been observed in China.7 The report does not name a subspecies.6", "Physiological races: some researchers report evidence of races of C. kahawae and others found none; in Kenya, differential pathogenicity was never observed1, and a test of Ruiru 11 progenies with seven isolates found no adaptation of the pathogen to the cultivar.11", "Scab lesions and resistance: a 1991 fact sheet notes that some researchers consider the scab lesion a resistant reaction but that this is not confirmed2; a 1982 histology study and a 2006 review link it to cork barriers that stop the fungus in resistant plants.1,9", "Where inoculum survives between crops: a 1970 review describes infective spores produced on the maturing wood of twigs8; a 1991 fact sheet states that CBD isolates are rarely recovered from tissues other than berries, and that other Colletotrichum strains live on bark.2" ], "corrections": [], "sources": [ { "id": "s1", "title": "Coffee resistance to the main diseases: leaf rust and coffee berry disease", "authors": "Silva, M. C.; Várzea, V.; Guerra-Guimarães, L.; Azinheira, H. G.; Fernandez, D.; Petitot, A.-S.; Bertrand, B.; Lashermes, P.; Nicole, M.", "year": 2006, "publisher": "Brazilian Journal of Plant Physiology 18(1), 119–147", "url": "https://www.scielo.br/j/bjpp/a/dTHqD9SqgdJtq9wHCf9Hp6R/?lang=en", "doi": "10.1590/S1677-04202006000100010", "tier": "A", "quote": "The highly resistant variety Rume Sudan carries the dominant R- and the recessive K-genes.", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s2", "title": "Colletotrichum coffeanum (Crop Knowledge Master)", "authors": "Ferreira, S. A.; Boley, R. A.", "year": 1991, "publisher": "Department of Plant Pathology, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa", "url": "https://cms.ctahr.hawaii.edu/ckm/Home/Plant-Disease-Pathogens/Fungi/Fungi-genera-starting-with-A--D/Colletotrichum-coffeanum", "tier": "A", "tierNote": "University extension fact sheet (November 1991).", "quote": "Coffee Berry Disease was first reported from Kenya in 1922.", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s3", "title": "Guía práctica para la diferenciación de frutos de café con síntomas de CBD en el campo (Avances Técnicos 558)", "authors": "Ferrucho, R. L.; Marín-Ramírez, G.", "year": 2023, "publisher": "Centro Nacional de Investigaciones de Café (Cenicafé)", "url": "https://publicaciones.cenicafe.org/index.php/avances_tecnicos/article/view/883", "doi": "10.38141/10779/0558", "tier": "A", "tierNote": "Technical publication of a national coffee research institute.", "quote": "La primera línea de defensa contra CBD es la exclusión.", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s4", "title": "Colletotrichum kahawae (COLLKA) – Distribution", "authors": "EPPO", "year": 2025, "publisher": "EPPO Global Database, European and Mediterranean Plant Protection Organization (distribution last updated 20 May 2025; country page for China gives the status “on the basis of information dated 2024”)", "url": "https://gd.eppo.int/taxon/COLLKA/distribution", "tier": "A", "quote": "Present, restricted distribution", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s5", "title": "Colletotrichum kahawae (COLLKA) – Categorization", "authors": "EPPO", "year": 2025, "publisher": "EPPO Global Database, European and Mediterranean Plant Protection Organization", "url": "https://gd.eppo.int/taxon/COLLKA/categorization", "tier": "A", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s6", "title": "First report of large-berry coffee (Coffea liberica) anthracnose caused by Colletotrichum kahawae in China", "authors": "Zhang, H. L.; Xie, Y. L.; Chen, H. M.; Su, Q. Q.; He, J.; Su, X. Y.; Wu, D. Y.; Zhou, H. M.; Yu, L. F.; Tan, W. Z.", "year": 2024, "publisher": "Plant Disease 108(7), 2236", "url": "https://busqueda.bvsalud.org/portal/resource/es/mdl-38720534", "tier": "A", "quote": "Between June and September 2022, anthracnose was observed on coffee plants in Puer area, Yunnan, China", "abstractOnly": true, "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s7", "title": "Diversity and pathogenicity of Colletotrichum species causing coffee anthracnose in China", "authors": "Lu, Y.; Zhang, W.; Hu, X.; He, C.; Liang, Y.; Huang, X.; Yi, K.; Wu, W.", "year": 2025, "publisher": "Microorganisms 13(3), 512", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC11946238", "doi": "10.3390/microorganisms13030512", "tier": "A", "quote": "It is also encouraging that C. kahawae, the main pathogen threatening coffee production in Africa,", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s8", "title": "Coffee berry disease", "authors": "Nutman, F. J.", "year": 1970, "publisher": "PANS Pest Articles & News Summaries 16(2), 277–286", "url": "https://kalroerepository.kalro.org/items/273d2d0c-755e-4cec-9bef-085771f4fc7d", "doi": "10.1080/09670877009411770", "tier": "A", "quote": "The disease was confined for many years to the higher altitudes", "abstractOnly": true, "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s9", "title": "Evidence of cork barrier formation as a resistance mechanism to berry disease (Colletotrichum coffeanum) in arabica coffee", "authors": "Masaba, D. M.; van der Vossen, H. A. M.", "year": 1982, "publisher": "Netherlands Journal of Plant Pathology 88(1), 19–32", "url": "https://link.springer.com/doi/10.1007/BF01976423", "doi": "10.1007/BF01976423", "tier": "A", "quote": "likely to be stable (race-nonspecific)", "abstractOnly": true, "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s10", "title": "Identification of molecular markers linked to a gene conferring resistance to coffee berry disease (Colletotrichum kahawae) in Coffea arabica", "authors": "Gichuru, E. K.; Agwanda, C. O.; Combes, M.-C.; Mutitu, E. W.; Ngugi, E. C. K.; Bertrand, B.; Lashermes, P.", "year": 2008, "publisher": "Plant Pathology 57(6), 1117–1124", "url": "https://agritrop.cirad.fr/546971", "doi": "10.1111/j.1365-3059.2008.01846.x", "tier": "A", "quote": "Two F2 populations from crosses of cv. Catimor (resistant) and cv. SL28 (susceptible)", "abstractOnly": true, "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s11", "title": "Resistance of Coffea arabica cv. Ruiru 11 tested with different isolates of Colletotrichum kahawae, the causal agent of coffee berry disease", "authors": "Omondi, C. O.; Ayiecho, P. O.; Mwang’ombe, A. W.; Hindorf, H.", "year": 2001, "publisher": "Euphytica 121(1), 19–24 (Springer Netherlands)", "url": "https://repository.maseno.ac.ke/handle/123456789/1928", "tier": "A", "tierNote": "Journal, volume and pages from the Pestinfo index of Euphytica 121; abstract read in the Maseno University repository record. DOI not confirmed.", "quote": "The coffee berry disease pathogen is unlikely to have adapted to the cultivar", "abstractOnly": true, "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s12", "title": "A review of three major fungal diseases of Coffea arabica L. in the rainforests of Ethiopia and progress in breeding for resistance in Kenya", "authors": "Hindorf, H.; Omondi, C. O.", "year": 2011, "publisher": "Journal of Advanced Research 2(2), 109–120", "url": "https://doaj.org/article/8284b5d707384e06bb2d2b0bc0630753", "doi": "10.1016/j.jare.2010.08.006", "tier": "A", "quote": "CBD was present mostly in Bonga (40.0%) and Yayu (26.3%), but less frequent in Harenna (18.6%) and Berhane-Kontir (6.0%).", "abstractOnly": true, "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s13", "title": "Additional physiological races of coffee leaf rust (Hemileia vastatrix) identified in Kenya", "authors": "Gichuru, E. K.; Ithiru, J. M.; Silva, M. C.; Pereira, A. P.; Várzea, V. M. P.", "year": 2012, "publisher": "Tropical Plant Pathology (short communication)", "url": "https://scielo.br/j/tpp/a/StL8f8kbms8gdYnwHz3QCdk/?lang=en", "tier": "A", "quote": "resulted in the release of the cultivar Ruiru 11 in 1985, which is resistant to CLR and CBD", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s14", "title": "The intensity of coffee berry disease (Colletotrichum kahawae Waller and Bridge) and its association with biophysical factors in Southern Ethiopia", "authors": "Wariyo, A.; Dejene, M.; Derso, E.; Bekeko, Z.", "year": 2025, "publisher": "Journal of Plant Pathology 107(1), 191–202", "url": "https://link.springer.com/article/10.1007/s42161-024-01658-4", "doi": "10.1007/s42161-024-01658-4", "tier": "A", "quote": "districts, altitudes, and cultivar types were the most important variables", "abstractOnly": true, "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s15", "title": "Coffee sustainability in Kenya: role played by improved varieties", "authors": "Gichimu, B. M.", "year": 2014, "publisher": "25th International Conference on Coffee Science (ASIC), Armenia, Colombia", "url": "https://researchgate.net/profile/Bernard-Gichimu/publication/281626727_Coffee_Sustainability_in_Kenya_Role_Played_by_Improved_Varieties/links/55f0746c08ae199d47c2110d/Coffee-Sustainability-in-Kenya-Role-Played-by-Improved-Varieties.pdf", "tier": "B", "quote": "it can cause up to 80% crop loss if not controlled and conditions are favourable", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s16", "title": "Cultivating Coffee Quality – Terroir and Agro-Ecosystem", "authors": "Lambot, C.; Herrera, J. C.; Bertrand, B.; Sadeghian, S.; Benavides, P.; Gaitán, A.", "year": 2017, "publisher": "In: Folmer, B. (ed.), The Craft and Science of Coffee, Academic Press, ch. 2, pp. 17–49", "url": "https://doi.org/10.1016/B978-0-12-803520-7.00002-5", "doi": "10.1016/B978-0-12-803520-7.00002-5", "tier": "B", "quote": "Coffee berry disease (Colletotrichum kahawae) is a devastating pathogen so far present exclusively in Africa.", "accessed": "2026-10-16T00:00:00.000Z" }, { "id": "s17", "title": "The Coffee Tree – Genetic Diversity and Origin", "authors": "Herrera, J. C.; Lambot, C.", "year": 2017, "publisher": "In: Folmer, B. (ed.), The Craft and Science of Coffee, Academic Press, ch. 1, pp. 1–16", "url": "https://doi.org/10.1016/B978-0-12-803520-7.00001-3", "doi": "10.1016/B978-0-12-803520-7.00001-3", "tier": "B", "tierNote": "Same book as source 16; the two chapters count as one source for the number rule.", "quote": "Ruiru 11 is another composite cultivar developed at the Coffee Research Station, Ruiru (Kenya), and released to the growers in 1985.", "accessed": "2026-10-16T00:00:00.000Z" } ], "markdown": "## What coffee berry disease is\n\nCoffee berry disease (CBD) is a fungal disease of arabica coffee (*Coffea arabica*). It is caused by *Colletotrichum kahawae*.10 Older papers call the fungus *Colletotrichum coffeanum*.9 It was first reported in Kenya in 1922.1,2\n\nThe fungus infects flowers and fruit at every stage, from flowers to ripe cherries, and occasionally leaves.1 The heaviest losses follow infection of green berries.1 Infected green berries develop dark brown spots that can cover the whole cherry and affect how the seed develops.16 Where nothing is done to control it, the disease can destroy up to 70–80% of the crop.1,2\n\nCoffee leaf rust attacks the leaves. Coffee berry disease attacks the flowers and fruit, the crop itself.1 In Kenya, a 2012 study ranks leaf rust as the second most important coffee disease, after CBD.13\n\n## Which stages of the fruit are at risk\n\nA coffee fruit takes months to grow from flower to ripe cherry. Its susceptibility changes along the way.2\n\n- **Flowers** can be infected at all stages.2\n- **Pinhead fruit**, the tiny fruit just after flowering, is fairly resistant.2\n- **Expanding green berries** are the most susceptible, about 4–14 weeks after flowering.2,16 Colombia’s coffee research institute, Cenicafé, gives the critical period as 4 to 14–20 weeks of fruit age.3\n- **Mature green berries**, hard and full-sized, are fairly resistant again.2\n- **Ripening berries** become susceptible once more.2\n\nThe disease shows two kinds of spot. An **active lesion** is a dark, sunken spot that spreads fast and can cover the whole berry. A pale pink crust of spores forms on it.2 A **scab lesion** is buff-coloured, grows slowly and produces few or no spores.2 According to a 2017 textbook chapter, a scab can stay latent until ripening and then damages mostly the pulp, not the seed.16\n\n
\n
\n

A · Fruit stages

\n
    \n
  1. Flowers. Susceptible at all stages of development.2
    2. \n
  2. Pinhead fruit. Fairly resistant.2
    3. \n
  3. Expanding green berry. Most susceptible, about 4–14 weeks after flowering2,16; 4 to 14–20 weeks of fruit age according to Cenicafé.3
    4. \n
  4. Mature (hard) green berry. Fairly resistant.2
    5. \n
  5. Ripening berry. Susceptible again.2
    6. \n
\n

B · Two kinds of lesion

\n
    \n
  1. Active lesion. Dark and sunken; spreads fast and can cover the berry; pale pink spore masses form on it.1,2
    2. \n
  2. Scab lesion. Buff and corky; grows slowly with little or no sporulation. A 2006 review links it to cork barriers that resistant plants form against the fungus.1,2,9
    3. \n
\n
When coffee fruit is susceptible to coffee berry disease, and the two kinds of lesion. Filled bars mark susceptible stages, hollow bars fairly resistant ones. Qualitative; schematic, not to scale.1,2,3
\n
\n\n## Rain, cool weather and altitude\n\nThe fungus needs free water from rain, mist or dew to infect.2 Rain is the main force that spreads it. Water running down branches and drops falling from diseased berries carry the spores, mostly downwards; wind-driven rain carries them a short way.2,3\n\nFor many years the disease was confined to higher altitudes.8 A 1970 review links its spread to a wetter and cooler phase of the East African climate in 1961.8 According to Cenicafé, the disease is most severe in the highlands of Africa.3 In a 2025 survey in southern Ethiopia, altitude was among the most important factors linked to disease intensity.14\n\nThe entry on site selection and climate covers how altitude shapes the coffee farm.\n\n## Resistant varieties\n\nBreeding has been the main answer. High fungicide costs led coffee research centres to give priority to breeding resistant varieties.1 According to a 2017 textbook chapter, resistant varieties have been available for some time and are a more effective solution than spraying.16\n\n- **Rume Sudan** is a highly resistant arabica variety.1\n- **The Timor Hybrid**, a natural cross of *C. arabica* and *C. canephora*, carries a resistance gene, and so do Catimor lines derived from it.1,10\n- **Ruiru 11** was released in Kenya in 1985 and **Batian** in 2010. Both resist CBD and leaf rust.13\n- **In Ethiopia**, about 20 pure lines with good tolerance to CBD were selected and given to producers from 1978 onwards.1 The entry on Ethiopian landraces describes the country’s own coffee populations.\n\nThe classic Kenyan varieties SL28 and SL34 are susceptible to CBD.10,15 The varieties themselves are covered in the entry on arabica varieties.\n\n## How the disease came to matter\n\n
\n
\n
    \n
  1. 1922. First report, in Kenya.1,2
    2. \n
  2. 1961. A wetter and cooler phase in East Africa is linked with the spread of the disease beyond the highest altitudes.8
    3. \n
  3. 1978. Ethiopia begins distributing about 20 tolerant pure lines.1
    4. \n
  4. 1985. Ruiru 11 released in Kenya.13
    5. \n
  5. 2010. Batian released in Kenya.13
    6. \n
  6. 2018–2021. Listed as a quarantine pest by Brazil and Mexico (2018) and China (2021).5
    7. \n
  7. 2022. Symptoms observed on Coffea liberica in Pu’er, Yunnan, China; reported as C. kahawae in 2024.6
    8. \n
\n
Coffee berry disease from the first report to the quarantine listings, 1922–2022. Accent markers are disease events, hollow rings resistant varieties. Dates to scale; markers schematic.1,5,6,8,13
\n
\n\nAccording to a conference paper on Kenyan varieties, outbreaks of CBD and leaf rust led Kenya to start breeding for disease resistance.15 Susceptible varieties in Kenya need intensive spray programmes against CBD, leaf rust and bacterial blight.15\n\n## Why other coffee regions watch for it\n\nThe European and Mediterranean Plant Protection Organization (EPPO) keeps a database of plant pests. As of October 2026, it lists the disease as present in 14 African countries, from Ethiopia and Kenya to Angola and Cameroon.4 Cenicafé gives 15 African countries, citing a 2022 CABI datasheet.3 Cenicafé calls the disease one of the main threats to the coffee industry in Asia and Latin America.3\n\nOutside Africa the picture changed in 2024. A report from Yunnan, China, identified the fungus on *Coffea liberica*.6 EPPO lists China as “present, restricted distribution”.4 A 2025 survey of coffee anthracnose in China, based on samples from 2019, did not find it (see Contested).7\n\nSeveral countries list *C. kahawae* as a quarantine pest, a pest that import rules aim to keep out.5 According to Cenicafé, exclusion is the first line of defence.3\n\n\n\n## The pathogen and its name\n\n*Colletotrichum kahawae* (authority Waller & Bridge) is listed by EPPO in the family Glomerellaceae, order Glomerellales, class Sordariomycetes.4 EPPO also lists the name *C. kahawae* subsp. *kahawae*.4 Older papers, such as a 1982 histology study, used the name *Colletotrichum coffeanum* for the berry disease pathogen.9 Literature that cites “*C. coffeanum*” therefore has to be read with care. A 1991 fact sheet distinguishes CBD isolates from other *Colletotrichum* strains that live on bark, and notes that related species cause other diseases in Guatemala and Brazil.2\n\nThe disease belongs to a wider group of fungal problems on coffee fruit. A 2017 textbook chapter lists CBD among the fungal diseases that attack coffee cherries, with berry blotch (*Cercospora coffeicola*), American leaf spot (*Mycena citricolor*), pink disease and oily spot (*Colletotrichum* spp.).16 Cenicafé lists the same and other diseases as possible confusions in the field, including anthracnose caused by other *Colletotrichum* species complexes.3\n\n## Infection and the two lesion types\n\n**Germination and entry.** After the conidia (asexual spores) germinate, they form appressoria that penetrate the cuticle directly.1 A short biotrophic phase, in which the fungus feeds on living cells, is followed by necrotrophic growth that kills the tissue.1\n\n**Temperature and water.** According to a 1991 University of Hawaii fact sheet, the optimum temperature for germination and lesion development is 22 °C. Germination can occur up to 30 °C, and the minimum is 10 °C. With added nutrients, the optimum rises to 27 °C and the maximum to 35 °C.2 Infection needs free water, and spores lose their infectivity after 10–12 days of drying.2\n\n**Active lesions.** These begin as small, dark, sunken spots that spread rapidly and can cover the berry. The fungus forms a pale pink crust of spores on the surface.2 The spore-bearing structures are acervuli; Cenicafé describes them as orange.1,3\n\n**Scab lesions.** These develop slowly, are buff-coloured and sporulate sparsely or not at all.2 In a 1982 histology study of inoculated berries and seedling hypocotyls, resistant varieties quickly formed a layer of cork cells beneath the infection that stopped the fungus.9 A 2006 review states that these cork barriers corresponded to the scab lesion.1\n\n**Effect on the seed.** According to the 2017 chapter, severe infection in the green stage produces dark brown spots that end up covering the cherry and affect bean development and quality.16 A milder attack forms a scab in which the infection stays latent until ripening and affects mostly the pulp.16\n\n## Epidemiology\n\n**Inoculum between crops.** A 1970 review describes infective conidia produced on the maturing wood of the twigs.8 Where only one crop hangs on the tree, reducing this twig inoculum can work; where crops overlap, control needs a series of protective sprays.8 A 1991 fact sheet states that CBD isolates are rarely recovered from tissues other than berries (see Contested).2\n\n**Dispersal.** Rain is the main factor in spread. Dispersal is mainly downwards in the tree, by water running along branches and drops from diseased berries, with wind-blown rain carrying spores over short distances.2 Cenicafé likewise describes short-distance dispersal of conidia by rain water.3\n\n**Altitude and site.** The disease was confined for many years to the higher altitudes, and its spread was associated with a wetter and cooler phase in East Africa in 1961.8 In southern Ethiopia, districts, altitudes and cultivar types were the most important variables associated with disease intensity in a 2025 study.14 No altitude band with a source meeting our number rule was found for this entry, so none is given.\n\n**Wild coffee.** In surveys of arabica in four Ethiopian montane rainforests, CBD was found most often in Bonga (40.0%) and Yayu (26.3%), and less often in Harenna (18.6%) and Berhane-Kontir (6.0%).12\n\n
\n
\n
Coffee berry disease in four Ethiopian montane rainforests with arabica coffee, as reported in the abstract of Hindorf & Omondi 2011.12
\n
\n\n## Losses\n\n| Report | Loss stated | Source |\n|---|---|---|\n| Review of coffee resistance, 2006 | Up to 70–80% if no control measures are adopted | Silva et al.1 |\n| University of Hawaii fact sheet, 1991 | Up to 80% not unusual in some areas; 75% on some Kenyan farms when the disease was first described; a more conservative Kenyan estimate of 20% | Ferreira & Boley2 |\n| Cenicafé field guide, 2023 | Production losses above 50%; up to 100% in susceptible cultivars | Ferrucho & Marín-Ramírez3 |\n| Kenyan conference paper, 2014 | Up to 80% if not controlled and conditions are favourable | Gichimu15 |\n| Review, 1970 | Total destruction of the crop possible | Nutman8 |\n\nThe figures are upper bounds for uncontrolled disease under favourable weather, not averages.1,15 They refer to different places and decades.\n\n## Genetics of resistance\n\n**Three loci.** A 2006 review, citing Kenyan work from 1980, describes resistance in arabica as apparently controlled by major genes at three loci.1 Rume Sudan carries the dominant R gene and the recessive k gene. The moderately resistant variety K7 carries only k. The Timor Hybrid carries one gene at the T locus, with intermediate gene action.1 Other authors estimated three to five recessive genes.1\n\n**Ck-1.** A 2008 mapping study crossed Catimor (resistant) with SL28 (susceptible).10 It found eight AFLP and two microsatellite markers tightly linked to a major resistance gene, named Ck-1, within an 11 cM segment introgressed from *C. canephora*.10 The authors consider Ck-1 likely to be the T gene of earlier studies.10\n\n**Species differences.** Resistance appeared complete in *C. canephora* and partial in *C. arabica*.1\n\n**Breeding results.** In Kenya, the complex hybrid Ruiru 11 showed a good level of resistance.1 Ruiru 11 (1985) and Batian (2010) combine resistance to CBD and leaf rust.13 According to the 2014 conference paper, Batian is tall and true-breeding, while SL28, SL34 and K7 are susceptible to CBD, leaf rust and bacterial blight; K7 resists some races of leaf rust.15 In Tanzania, eight clones with high levels of resistance were selected and multiplied vegetatively.1 In Ethiopia, about 20 pure lines with good tolerance were distributed to producers from 1978.1 The 2011 review of fungal diseases in Ethiopia and breeding in Kenya describes 40 years of breeding against leaf rust, CBD and coffee wilt disease.12\n\n## Durability of resistance\n\nNo breakdown of CBD resistance is reported in the studies opened for this entry.\n\n- **Mechanism.** The 1982 histology study concluded that cork barrier formation is likely to be stable and race-nonspecific.9\n- **Quantitative resistance.** Earlier authors suggested that CBD resistance is horizontal (quantitative), and differential host–pathogen interactions were seldom found in Ethiopia.1\n- **No adapted races in Kenya.** Differential pathogenicity was never observed in Kenya.1 In tests of progenies from 66 crosses of Ruiru 11 with 7 isolates of different pathogenicity, crosses and isolates both had significant effects, but their interaction did not. The authors concluded that the pathogen is unlikely to have adapted to the cultivar.11\n- **Disagreement.** Some researchers report evidence for physiological races of *C. kahawae*; others found none.1\n\nThe entry on coffee leaf rust describes, for comparison, how rust resistance from the Timor Hybrid has been lost in several varieties.\n\n## Chemical control and its cost\n\nFungicides are used to keep CBD in check on susceptible varieties. According to the 2017 chapter, periodical applications are required.16 A 2006 review calls the costs of fungicides against leaf rust and CBD extremely high, and names difficulties of application.1\n\n- **Timing.** A 1991 fact sheet reports that early-season applications work only when flowering is early and the rainy season ends early.2 Where crops overlap on the tree, control requires a series of protective sprays.8\n- **Product groups.** The same fact sheet recommends that systemic fungicides be mixed or rotated with non-systemic protectants.2 Coffearium does not give product or dose advice.\n- **Cost.** A share of production costs for CBD sprays alone was not found in a source that meets our number rule, so none is given.\n\n## Quarantine and the risk for Latin America and Asia\n\n**Listings.** The EPPO database records *C. kahawae* on the A1 list of Brazil (2018) and as a quarantine pest in Mexico (2018) and China (2021).5\n\n**Pathways.** According to Cenicafé, spread by seed has not been demonstrated, but the pathogen can be present as a surface contaminant on beans.3 Rules may prohibit or restrict imports of coffee plant material, and travellers carrying infected plant material are named as a risk.3 The 1991 fact sheet advises taking seed only from healthy berries, treating it with a fungicide seed dressing and bringing cultivars in through quarantine facilities.2\n\n**Detection.** Cenicafé published a field guide in 2023 so that symptoms can be told apart from other fruit diseases, for rapid containment and eradication of any incursion into Colombia.3 In Colombia, Cenicafé warns that the disease could cause large losses and higher production costs in susceptible varieties.3\n\n**Distribution as of October 2026.** The EPPO table (last updated 20 May 2025) gives:4\n\n| Region | Status in the EPPO database | Source |\n|---|---|---|\n| Angola, Burundi, Cameroon, Central African Republic, Congo, Democratic Republic of the Congo, Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda, Zambia, Zimbabwe | Present, no details | EPPO4 |\n| Mozambique | Absent, unreliable record | EPPO4 |\n| Cuba | Absent, unreliable record | EPPO4 |\n| China | Present, restricted distribution (Yunnan: few occurrences), on information dated 2024 | EPPO4; Zhang et al.6 |\n\nA 2017 textbook chapter and a 2006 review both describe the disease as present only in Africa.1,16 The Chinese record is newer than both. The CABI datasheet itself was not opened for this entry.\n\n## What it means for the cup and the buyer\n\nAccording to the 2017 chapter, there is no evidence that diseases change the synthesis of specific compounds in the bean directly; their effect runs through the plant and the fruit.16 Severe CBD affects bean development and quality, while scab affects mostly the pulp.16 The entry on harvesting and sorting describes how diseased cherries are removed before processing.\n\nFor buyers, the disease matters through varieties. In Kenya, SL28 and SL34 are susceptible, while Ruiru 11 and Batian are resistant.13,15 According to a 2017 textbook chapter, Ruiru 11 combines resistance to CBD and leaf rust with high yield and compact growth, and a later report pointed to component lines that combine high cup quality with CBD resistance.17\n\n## Reference values\n\n| Parameter | Value reported | Source |\n|---|---|---|\n| Pathogen | *Colletotrichum kahawae* (older literature: *C. coffeanum*) | Gichuru et al.10; Masaba & van der Vossen9 |\n| First report | Kenya, 1922 | Silva et al.1; Ferreira & Boley2 |\n| Organs attacked | Flowers and fruit at all stages; occasionally leaves | Silva et al.1 |\n| Most susceptible fruit | Expanding green berries, about 4–14 weeks after flowering; 4 to 14–20 weeks of fruit age | Ferreira & Boley2; Lambot et al.16; Cenicafé3 |\n| Fairly resistant fruit | Pinhead and mature green berries | Ferreira & Boley2 |\n| Germination temperature | Optimum 22 °C; maximum 30 °C; minimum 10 °C (without added nutrients) | Ferreira & Boley2 |\n| Water | Free water needed; infectivity lost after 10–12 days of drying | Ferreira & Boley2 |\n| Dispersal | Rain water, short distances, mainly downwards | Ferreira & Boley2; Cenicafé3 |\n| Losses without control | Up to 70–80%; up to 80%; above 50%, up to 100% in susceptible cultivars | Silva et al.1; Ferreira & Boley2; Cenicafé3 |\n| Resistance genes | R and k (Rume Sudan), k (K7), T (Timor Hybrid); Ck-1 likely = T | Silva et al.1; Gichuru et al.10 |\n| Resistant Kenyan varieties | Ruiru 11 (1985), Batian (2010) | Gichuru et al. 201213 |\n| Countries listed (Oct 2026) | 14 African countries present; China restricted | EPPO4 |\n\n## Open questions\n\n- **Status in China.** Whether *C. kahawae* is established in Yunnan, and which subspecies the isolate belongs to, is not settled in the sources opened here (see Contested).4,6,7\n- **Races.** Whether the fungus forms physiological races that could overcome resistance genes is debated.1,11\n- **Altitude band.** Sources agree that the disease is worse at higher altitude in Africa, but no altitude range with adequate sourcing was found.3,8,14\n- **Climate change.** No study opened for this entry projects how warming will move the disease’s altitude range.\n\n## Key studies\n\n
\n

Silva et al., 2006 – Coffee resistance to leaf rust and coffee berry disease. A review of the two main fungal diseases of arabica. For CBD it covers the infection process, cork barriers and the scab lesion, the R, k and T resistance genes, the debate on races and the main breeding programmes in Kenya, Tanzania and Ethiopia.

\n

Brazilian Journal of Plant Physiology 18(1), 119–147 · doi:10.1590/S1677-04202006000100010

\n
\n\n
\n

Masaba & van der Vossen, 1982 – Cork barriers against berry disease. Inoculated berries and seedling hypocotyls of resistant and susceptible arabica. Resistant plants quickly walled off the fungus with a layer of cork cells; the reaction matched field resistance and was judged likely to be race-nonspecific.

\n

Netherlands Journal of Plant Pathology 88(1), 19–32 · doi:10.1007/BF01976423

\n
\n\n
\n

Gichuru et al., 2008 – Markers for a CBD resistance gene. Mapped resistance in two F2 populations of Catimor × SL28. Found markers tightly linked to a major gene, Ck-1, on a segment from C. canephora, probably the T gene of earlier studies; resistance was screened in seedlings.

\n

Plant Pathology 57(6), 1117–1124 · doi:10.1111/j.1365-3059.2008.01846.x

\n
\n\n
\n

Hindorf & Omondi, 2011 – Fungal diseases in Ethiopian rainforests and breeding in Kenya. Surveyed leaf rust, CBD and coffee wilt disease in wild arabica in four Ethiopian forests and reviewed Kenyan resistance breeding. CBD was most frequent in Bonga and least in Berhane-Kontir.

\n

Journal of Advanced Research 2(2), 109–120 · doi:10.1016/j.jare.2010.08.006

\n
\n\n
\n

Zhang et al., 2024 – First report of C. kahawae in China. Described anthracnose on leaves and berries of Coffea liberica in Pu’er, Yunnan, in 2022. The fungus was identified by morphology, pathogenicity tests and multi-gene sequencing; it is the basis of EPPO’s listing of China.

\n

Plant Disease 108(7), 2236 · record

\n
" }