CHIZU — the atlas of coffee research
Coffee research in Yemen
Two limits come with this count. Only 100,474 of the 190,643 searchable papers (52.7%) carry an author affiliation country. The other 90,169 (47.3%) carry none. So these 73 papers are 73 out of the 100,474 whose affiliation is known. And a co-authored paper is counted once for every country its authors sit in. Per-country counts therefore do not add up to the whole.
Yemen is a coffee-producing country.
Check it yourself
This is not our word for it. You can run the same query against the same index.
When they were written
2000–2026
Years before 1600 are treated as unknown. The upstream data (OpenAlex) sometimes writes 1400 when the year is missing, and that is a placeholder, not a measurement.
Where they appeared
Top 8 sources (journals and repositories)
Most cited
10 papers, most cited first
- Pest Management Strategies in Traditional Agriculture: An African Perspective2000cited 409
- Influence of pyrolysis temperature on polycyclic aromatic hydrocarbons production and tetracycline adsorption behavior of biochar derived from spent coffee ground2019cited 213
- Cobalt-impregnated biochar (Co-SCG) for heterogeneous activation of peroxymonosulfate for removal of tetracycline in water2019cited 163
- A single polyploidization event at the origin of the tetraploid genome of Coffea arabica is responsible for the extremely low genetic variation in wild and cultivated germplasm2020cited 148open access
- Adsorption of norfloxacin from aqueous solution on biochar derived from spent coffee ground: Master variables and response surface method optimized adsorption process2021cited 143
- Prevalence of Iron Deficiency Anemia among University Students in Hodeida Province, Yemen2018cited 98open access
- Khat Use: History and Heart Failure2015cited 84open access
- Antioxidant Activity of Some Edible Yemeni Plants Evaluated by Ferrylmyoglobin/ABTS*+ Assay.2001cited 65open access
- The short-term effect of water-pipe smoking on the baroreflex control of heart rate in normotensives2006cited 61
- Unveiling a unique genetic diversity of cultivated Coffea arabica L. in its main domestication center: Yemen2021cited 51open access
Which stage of coffee
Only 30.2% of the whole index carries a stage label. Of this country's 73 papers, 24 carry one. The breakdown below is about those 24 papers only — the rest were never candidates for it.
One paper can carry several labels, so the breakdown adds up to more than that number.
Which field
Only 75.9% of the whole index carries a field label. Of this country's 73 papers, 51 carry one. The breakdown below is about those 51 papers only — the rest were never candidates for it.
One paper can carry several labels, so the breakdown adds up to more than that number.
What language
"undetermined" means the upstream record carried no language. We did not guess one.
Knowledge is not evenly spread
Counting only papers whose author affiliation is known, the largest is Indonesia with 22,248. Yemen has 73 — a factor of 305.
That gap does not follow where coffee is grown. Research gathers where the means to do research are, not where the coffee is. Making that visible is why CHIZU exists.
Other countries
Indonesia 22,248United States 17,988Brazil 10,857United Kingdom 5,569China 4,887India 3,542Germany 3,185Italy 3,111France 3,072Japan 2,822Colombia 2,489Spain 2,363