DR CONGO
By Meise Botanic Garden, INERA DRC & KU Leuven
0° 51' 1.4” N, 24° 27' 55.7” E
Robusta coffee makes up 40% of global production but is often seen as inferior to Arabica. Known for its bold flavours and high caffeine content, it is typically used in instant coffee. However, Robusta’s resilience to heat and disease makes it crucial for tackling climate change. The rainforest of Yangambi in DR Congo holds a rich underexplored diversity of Robusta coffee. Researchers from Meise Botanic Garden and KU Leuven, in collaboration with INERA DRC, discovered unique Robusta varieties with fruity aromas, chocolate notes, and low caffeine. These promising Robusta varieties were then locally cultivated in an agroforestry system, supported by Flanders’ international climate finance.
Sustaining Coffee Production in the Democratic Republic of the Congo
Research and Innovation for the Future
The Democratic Republic of the Congo (DRC) holds immense potential for coffee cultivation, particularly in Robusta (Coffea canephora), a species known for its resilience and disease resistance. However, the sector has faced significant challenges, including political instability, environmental degradation, and a lack of investment. In response, research institutions such as Meise Botanic Garden, KU Leuven, and INERA, with funding from the Flemish government’s international climate finance, have launched projects to strengthen the sustainability of coffee production. These initiatives not only aim to restore and improve Robusta coffee farming in the region but also explore the conservation of wild coffee species and the impact of climate change on coffee plants.
Agroforestry and Genetic Conservation
Key Strategies for Coffee Resilience
The ClimCoff and CoffeeBridge projects, operating in Yangambi (Tshopo Province), focus on integrating coffee cultivation into agroforestry systems. Agroforestry, which involves planting coffee alongside shade trees and other crops, enhances soil health, boosts biodiversity, and increases economic resilience for farmers. Research plots are evaluating optimal planting distances and fertilisation techniques to develop best practices. Furthermore, the projects invest in post-harvest processing infrastructure, ensuring high-quality coffee production and marketability. In parallel, the INERA Coffee Collection in Yangambi, a genetic repository of Robusta coffee, is being rehabilitated, revealing a rich diversity of genetic resources crucial for breeding improved coffee varieties. The collection includes wild accessions and hybrids, with studies confirming the presence of unique genetic fingerprints that could contribute to the development of high-quality and climate-resilient Robusta coffee.
Sustainable Coffee Cultivation in D.R. Congo
Open and read the "Sustainable Coffee Cultivation in D.R. Congo" folder.
The Role of Wild Coffee in Sustainable Agriculture
Wild coffee populations play a fundamental role in sustaining global coffee production, particularly in the face of climate change. However, there are concerns about gene flow between cultivated and wild coffee. A study in Yangambi found that while hybridisation between cultivated and wild Coffea canephora occurs near human settlements, the overall risk of genetic introgression remains limited. This suggests that wild coffee populations in the region still retain high genetic integrity, making them valuable for future breeding programmes. Another study on the genetic diversity of wild Robusta coffee in different forest conditions revealed that while disturbed forests did not show genetic erosion, regrowth forests had lower allelic richness due to founder effects. These findings stress the need for continuous conservation efforts to protect the genetic diversity of wild Robusta coffee in the DRC.
Climate Change and Coffee Adaptation
Insights from Leaf Trait Evolution
Climate change is altering the physiological traits of coffee plants, influencing their ability to adapt to changing environments. Research on African Coffea species has shown that leaf traits, particularly stomatal size and density, have evolved in response to atmospheric CO₂ fluctuations. Early-diverging Coffea species tend to have larger but fewer stomata, while more recent species display smaller, denser stomata, an adaptation that likely improves water-use efficiency under increasing CO₂ levels. Furthermore, leaf size correlates with precipitation, with smaller leaves occurring in drier climates. A separate study analysing understory woody species in the Congo Basin over 60 years found significant changes in leaf traits, with modern leaves exhibiting higher Specific Leaf Area and reduced stomatal density, likely due to rising temperatures and increased CO₂ concentrations. These findings provide valuable insights into how coffee plants and other tropical species may respond to future climate challenges, reinforcing the importance of genetic conservation and adaptive breeding.
UNLOCKING QUALITY POTENTIAL
SENSORY PROFILES OF ROBUSTA COFFEE
While Robusta coffee is often perceived as having a harsher flavour than Arabica, recent research has demonstrated considerable sensory variation within Robusta genotypes. Studies on the INERA Coffee Collection identified unique flavour profiles among wild and hybrid Robusta accessions. While Nutty/Cocoa was the most common descriptor, some genotypes exhibited Fruity, Sweet, and Sour/Fermented notes, characteristics typically associated with higher-quality coffee. The consistency of these sensory attributes over two consecutive harvest years suggests that selective breeding of superior Robusta varieties could expand the market potential of Congolese coffee, offering farmers better economic opportunities while maintaining genetic diversity.
The ongoing research conducted in the DRC highlights the importance of agroforestry, genetic conservation, and climate adaptation in securing the future of coffee production. By integrating scientific insights with practical applications, projects like ClimCoff and CoffeeBridge are providing sustainable solutions that benefit both farmers and the environment. Furthermore, the genetic diversity found in wild and cultivated Robusta populations offers a valuable resource for breeding improved coffee varieties that can withstand climate change while delivering superior cup quality. As global coffee production faces mounting challenges, the lessons learned from these initiatives can serve as a blueprint for sustainable coffee cultivation worldwide.
KNOWLEGDE KNOWS NO END.
References
Bollen, R., Rojo-Poveda, O., Verleysen, L., Ndezu, R., Tshimi, E. A., Mavar, H., Ruttink, T., Honnay, O., Stoffelen, P., Stévigny, C., Souard, F., & Delporte, C. (2024). Metabolite profiles of green leaves and coffee beans as predictors of coffee sensory quality in Robusta (Coffea canephora) germplasm from the Democratic Republic of the Congo. Applied Food Research, 4(2), 100560. https://doi.org/10.1016/j.afres.2024.100560
Bollen, R., Verleysen, L., Katshela, B. N., Kambale, J.-L., Ebele, T., Ruttink, T., Vandelook, F., Honnay, O., & Stoffelen, P. (2024). Sensory profiles of Robusta coffee (Coffea canephora) genetic resources from the Democratic Republic of the Congo. Frontiers in Sustainable Food Systems, 8. https://doi.org/10.3389/fsufs.2024.1382976
Depecker, J., Asimonyio, J. A., Miteho, R., Hatangi, Y., Kambale, J.-L., Mwanga Mwanga, I., Ebele, T., Dhed’a, B., Stoffelen, P., Vandelook, F., & Honnay, O. (2022). The association between rainforest disturbance and recovery, tree community composition, and community traits in the Yangambi area in the Democratic Republic of the Congo. Journal of Tropical Ecology, 38(6), 426–436. https://doi.org/10.1017/S0266467422000347
Depecker, J., Verleysen, L., Asimonyio, J. A., Hatangi, Y., Kambale, J.-L., Mwanga Mwanga, I., Ebele, T., Dhed’a, B., Bawin, Y., Staelens, A., Stoffelen, P., Ruttink, T., Vandelook, F., & Honnay, O. (2023). Genetic diversity and structure in wild Robusta coffee (Coffea canephora A. Froehner) populations in Yangambi (DR Congo) and their relation to forest disturbance. Heredity, 130, 145–153. https://doi.org/10.1038/s41437-022-00588-0
Hatangi, Y., Nshimba, H., Stoffelen, P., Dhed’a, B., Depecker, J., Lassois, L., & Vandelook, F. (2023). Leaf traits of understory woody species in the Congo Basin forests changed over a 60-year period. Plant Ecology and Evolution, 156(3), 339–351. https://doi.org/10.5091/plecevo.104593
Hendrickx, A., Hatangi, Y., Honnay, O., Janssens, S. B., Stoffelen, P., Vandelook, F., & Depecker, J. (2024). Leaf functional trait evolution and its putative climatic drivers in African Coffea species. Annals of Botany, 134(4), 683–698. https://doi.org/10.1093/aob/mcae111
Verleysen, L., Bollen, R., Kambale, J.-L., Tshimi, E., Katshela, B. N., Depecker, J., Poncet, V., Assumani, D.-M., Vandelook, F., Stoffelen, P., Honnay, O., & Ruttink, T. (2023). Characterization of the genetic composition and establishment of a core collection for the INERA Robusta coffee (Coffea canephora) field genebank from the Democratic Republic of Congo. Frontiers in Sustainable Food Systems, 7. https://doi.org/10.3389/fsufs.2023.1239442
Verleysen, L., Depecker, J., Bollen, R., Asimonyio, J., Hatangi, Y., Kambale, J.-L., Mwanga Mwanga, I., Ebele, T., Dhed’a, B., Stoffelen, P., Ruttink, T., Vandelook, F., & Honnay, O. (2024). Crop-to-wild gene flow in wild coffee species: The case of Coffea canephora in the Democratic Republic of the Congo. Annals of Botany, 133(7), 917–930. https://doi.org/10.1093/aob/mcae034
