ProMED
http://www.promedmail.org

Source: Voie de Femme [in French, machine trans., summ. Mod.DHA, edited]
https://voiedefemme.net/dossier-de-la-semaine/gagnoa-pourquoi-la-production-du-cafe-a-t-elle-baisse/

Coffee wilt (tracheomycosis) appeared in Ivory Coast in the 1930s and 1950s, destroying many coffee plantations. At that time, more resistant varieties of coffee were introduced. Now, the disease is back in all coffee-producing areas of the country.

A survey in 2022 showed that of 169 plots visited in parts of Goh-Djiboua district, 14.2% were affected by coffee wilt; in upper Sassandra district, orchard contamination rate is estimated at 50%. Scientists are working to develop techniques so that growers can manage the disease.

[Byline: Alain Doua]

--
Communicated by:
Dr E. Boa
University of Aberdeen
<e.boa@abdn.ac.uk>

[Coffee wilt (CW) disease (also called tracheomycosis) is caused by the fungus _Fusarium xylarioides_ (Fx; previously _Gibberella xylarioides_). A number of strains exist with different host preferences for (1) _Coffea canephora_ (robusta or lowland coffee); (2) _Coffea arabica_(arabica or highland coffee); and (3) other _Coffea_ spp. Of these, the robusta strains are the most aggressive and have caused the worst losses to commercial coffee cultivation.

CW can attack all stages of growth; infected plants show 100% mortality. Symptoms include wilting, defoliation and streaks in the wood; they occur sequentially until all branches are killed. Berries ripen prematurely and dry up. Pathogen spread occurs with infected plant material (firewood, seedlings), contaminated soil or tools, and by wind, water and mechanical means. Although cultural practices have shown some success in disease management, crop varieties with higher levels of CW resistance appear to be the most promising approach. CW-resistant varieties are being developed, but in the past problems were encountered in the region with distributing them to farmers.

Previously, the disease occurred sporadically in Africa, decimating coffee production in the 1920s-1950s. It re-emerged in the 2000s and is now considered a major constraint to African coffee production. Recent research on Fx genetics suggests that different populations arose independently and that Fx can increase its virulence by acquiring genes from related _Fusarium_ species (see links below).

Maps
Ivory Coast:
http://www.lib.utexas.edu/maps/africa/ivory_coast_pol88.jpg and
https://i.pinimg.com/originals/6c/05/4d/6c054d2757c204ea2cb3e561ea1ece2a.jpg (districts)

Pictures
Coffee wilt symptoms:
https://scx1.b-cdn.net/csz/news/800a/2021/70-year-old-coffee-kil-1.jpg,
https://coffeegeography.com/wp-content/uploads/2021/06/Coffee-Wilt-Disease-2.jpg,
https://coffeegeography.com/wp-content/uploads/2021/06/Coffee-Wilt-Disease.jpg,
https://d3i71xaburhd42.cloudfront.net/1b56a65f15d17f5c915eb91671fe2772c711c574/5-Figure2-1.png,
https://www.hawaiicoffeeed.com/uploads/2/6/7/7/26772370/1-s2-0-s2090123210001050-gr7-2.jpg and
https://image.slidesharecdn.com/coffeewiltdiseaseresistancebreedinginuganda-november2012-140212072716-phpapp02/95/coffee-wilt-disease-resistance-breeding-in-uganda-november-2012-7-638.jpg
_F. xylarioides_ hyphens, microscopy:
https://scx1.b-cdn.net/csz/news/800a/2021/70-year-old-coffee-kil.jpg

Links
Additional news story (in French):
https://www.aip.ci/cote-divoire-aip-le-cnra-forme-les-agents-anader-a-la-lutte-contre-les-maladies-du-cafeier-a-gagnoa/
Coffee wilt, disease and pathogen information:
https://doi.org/10.1079/cabicompendium.25166,
https://doi.org/10.1079/pwkb.20117800546,
https://doi.org/10.1094/PHYTO-04-15-0097-R,
https://www.earth.com/news/coffee-killing-fungus-has-acquired-genes-from-its-relatives/,
https://sca.coffee/sca-news/25/issue-16/malawis-unfulfilled-promise-the-impact-of-coffee-wilt-disease-and-subsidies-on-coffee-production,
https://www.hawaiicoffeeed.com/uploads/2/6/7/7/26772370/what_is_coffee_wilt_disease.pdf,
https://doi.org/10.1094/PHYTO-96-0663 and via
https://www.cabidigitallibrary.org/doi/book/10.1079/9781845936419.0000
Research on _F. xylarioides_ genetics:
https://doi.org/10.1186/s12864-021-07700-4,
https://phys.org/news/2021-06-year-old-coffee-killing-fungus-brought-life.html,
https://www.earth.com/news/coffee-killing-fungus-has-acquired-genes-from-its-relatives/ and
https://coffeegeography.com/2021/06/05/researchers-activated-70-year-old-coffee-killing-fungus-in-the-lab-to-fight-the-disease/
CW, recent review via:
https://www.bspp.org.uk/category/Plant-Pandemic-Studies/
_F. xylarioides_ taxonomy & synonyms:
https://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=286515 and
https://www.speciesfungorum.org/GSD/GSDspecies.asp?RecordID=286515
- Mod.DHA