By Howard Bryman
Previously unknown populations of potentially drought-resistant wild robusta coffee have been discovered by a team of Ugandan, Dutch, and French scientists in endangered forests in Uganda. The researchers hope the discovery will be helpful to the coffee industry by aiding in the development of drought-resistant cultivars.
As coffee is also a product of critical export value to the country of Uganda, another potential benefit of the discovery is to underscore the value of its rainforests, discouraging further deforestation and motivating the government to provide greater protections.
The study, conducted over a five year period from 2014-2019, involved research on wild robusta samples collected by Catherine Kiwuka amid her work towards a PhD at Wageningen University. The previously unknown genotypes were phenotyped for drought tolerance, revealing the climate-resistant potential of certain populations.
"[The drought-resistant varieties] can be used in breeding programs, such as crossing them with the existing varieties," Kiwuka's promotor professor Niels Anten, professor in crop & weed ecology of Wageningen University & Research, told STiR Magazine. "Many of the currently used varieties have been bred for disease resistance. Thus, by crossing the material found by Catherine with this material, one could potentially combine disease resistance with drought tolerance."
Key species from the study were found in the acutely threatened Zoka forest in Northern Uganda, of which only about 10 square kilometers remain.
"Mostly it is conversion to agricultural land that is threatening the forests," said Anten.
Other samples taken from areas further south are in danger of disappearing as they grow increasingly genetically mixed with commonly cultivated varieties, highlighting the need for conservation and protection of the critical genetic resources in wild coffee populations.
Improving the drought resistance of coffee crops would be of particular benefit to the millions of smallholder Ugandan farmers that are involved in the production of coffee and that tend to lack the means to install irrigation systems to deal with dry conditions.
Anten added that while drought-resistant crops may contribute to an improved quality of life for Ugandan farmers, this would ideally come as only one part of a package of efforts including education on better agronomic practices such as pruning or mulching and agroforestry techniques, and providing greater and more direct access to global markets.
"Providing them more drought tolerant material could help," said Anten. "Though I also want to emphasize that much more is needed than simply providing better varieties."
While robusta coffee is generally regarded by global markets as being of lower quality than arabica, Ugandan robusta is considered exceptional, measuring up more closely to the quality of arabica. Roughly 7 million 60-kilo bags of coffee, Uganda's leading agricultural source of revenue, has been produced for the year 2019/20. The government has previously announced a goal to increase annual exports up to at least 20 million bags within the next 10 years.