Wild Coffee Confirmed on the Upper Boma Plateau, Collected for Genetic Analysis; Or, My Star-Studded Botanical Treasure-Hunt

Wild Coffee Confirmed on the Upper Boma Plateau, Collected for Genetic Analysis; Or, My Star-Studded Botanical Treasure-Hunt

World Coffee Research Initiative in South Sudan 
By Emma Sage, SCA Coffee Science Manager

The Scene:   It was the tail end of the dry season in South Sudan. Our base camp, located in the small village of Jonglei, was dusty and despite being at 1100 meters elevation, was well above 90 degrees Fahrenheit. I had just hiked up all 1100 of these meters, much of which were unshaded, with only the water I could carry. Small huts made of mud and straw sat in the shade of large, broad leaved trees. There was a loud thump next to me and when I looked down I discovered a blushing yellow-green mango. The village was full of mango trees (or maybe, the mango grove was full of village). Somehow, in the most desolate season, these mango trees produce an astonishing abundance of beautiful huge fruit, oozing with sweet juicy nectar for all thirsty residents (and visiting scientists) to consume to their heart’s content. It is an amazing feat and I could not help but stop and revel in the sheer ingenuity of those trees. The mango roots systems must have been extensive and the trees resilient to support such production during the long dry season. A moment short lived, I only marveled as long as it took me to get out my knife and dig into a thirst quenching fruit. I was not there for the mangos; I was there in search of something more elusive, perhaps an even more extraordinary plant, Coffea arabica.

The Intrigue:  Right across the border from Ethiopia (widely regarded as the birthplace of C. arabica), is a small range of mountains in South Sudan known as the Boma Plateau. These mountains are traditionally home to the Transitional Rain Forest ecosystem and sport steep rocky cliffs as well as valleys filled with dense forests of tall, muscular looking trees, scattered palms, vines, and a thick shrubby understory. For years there has been talk of C. arabica varieties that include south Sudanese stock, but there is little evidence of when they were bred, how they were spread across coffee growing regions, or any more specific history. We do know that in the late 1930’s a botanist working in Kenya documented C. arabica, and brought some unidentified stock to agricultural research stations and labs in other countries within Africa. Since then, as far as we know the country’s political climate and civil war has kept any Coffea botanists at bay. That is, until last year, when a group of concerned coffee professionals, led by World Coffee Research (WCR) Executive Director Dr. Schilling, made the journey to the Plateau to confirm the rumors that C. arabica continued to grow in the Upper Boma mountains.

The Project: During the first two weeks of April, I had the opportunity to participate in the beginnings of a joint project with WCR, the Borlaug Institute, and USAID to work with John Garang Memorial University of Science and Technology (JG-MUST) in the Jonglei State of South Sudan. The purpose of WCR’s involvement in this partnership is to provide opportunities for South Sudanese JG-MUST students to gain practical field experience in botany, agronomy and coffee sector development.  This will occur specifically through an evaluation of C. arabica land races occurring in the Boma forest and through the examination of the feasibility of C. arabica coffee sector development in South Sudan. The purpose of this first mission was to collect plant tissue samples for genetic diversity analyses. Because of the close relationship between the SCAA and WCR, I was able to participate in this trip and experience firsthand the search for C. arabica. Half treasure hunt, half botanical fantasia, this trip led us on a journey into some of the most rural wildlands of the newest country on earth, South Sudan.

For those who are not yet familiar, World Coffee Research, is a 501(c)(5) non-profit organization funded by the coffee industry, dedicated to the sustainability and growth of the high-quality arabica coffee supply chain and improved coffee farmer livelihoods through collaborative research and development. We use to know them as the Global Coffee Quality Research Initiative (GCQRI). For more information about WCR projects and initiatives, visit http://worldcoffeeresearch.org/. It recently had its first board meetings and is ready to begin its first year of research!

WCR’s goals include germplasm preservation for the development of new varieties as well as the development new C. arabica breeding populations. These stem from a great need in the coffee industry to preserve and expand the genetic material within C. arabica. Currently, the genetics of cultivated coffee are restricted (not very diverse) and in biology this leads to vulnerability. In fact, a recent Ethiopian dissertation on coffee estimates that the genetic diversity among current cultivated varieties of C. arabica only represents 10% of the species’ natural genetic variability. The WCR website elaborates: “most varieties today are not likely to be ready to tolerate new disease and insect pressures as well as increased heat and other environmental threats posed by climate change.” A collection from South Sudan will help further the goal of documenting the genetic variation of the species and preserving the collected live germplasm. In the future, WCR will return to the region to collect live gene material for preservation, as well as propagation, and perhaps even variety trials.

The Expedition: On the trip was mission leader Dr. Schilling of WCR, backed by Dr. Aaron Davis, leader of the Rubiaceae Team at Royal Botanic Gardens, KEW, in London, and Dr. Sarada Krishnan, Director of Horticulture at the Denver Botanic Gardens. Other participants included Lindsey Bolger, Director of Coffee Sourcing & Relationships at Green Mountain Coffee Roasters, Solomon Moore, East African correspondent to the Wall Street Journal (look for a story on WCR in the WSJ in the near future) a lecturer in agronomy and two students from JG-MUST, a representative from the South Sudan Jonglei State Ministry of Agriculture, and yours truly Emma Sage, SCAA Coffee Science Manager. Add some hired porters and armed forest rangers (read, guards), a local guide, and you have the crew of botanical Coffea treasure-hunters.

We flew into Juba, the new capital of the South Sudan, where we compiled our group and supplies for the trip. We chartered a small plane to Lower Boma, about an hour and a half by plane, (or four days by car), North East of Juba. After hiring our local help, we walked to the base camp, located in the village of Jonglei in the Upper Boma region of the plateau. From there, for four memorable days we hiked into the mountains to investigate areas where we hoped C. arabica would be growing.

The Treasure Map and its Keeper:  Our very own Coffea genus expert, Dr. Davis, led the charge once we entered the forest, as he is extremely knowledgeable of the natural environment of all Coffea species. Truth be told, the entire trip we were referencing one short paper written in 1942 by one botanist A. S. Thomas. He had written the paper, titled “The wild arabica coffee on the Boma Plateau, Anglo-Egyptian Sudan”. This was effectively our treasure map. In the paper, Thomas had outlined his own journey to the Boma region in the late 1930’s. In it, he described different areas of the plateau where he observed C. arabica to be “locally frequent, growing as a small tree…” He also gave tantalizing insights such as “…it was impossible to assess how much of the variation was due to genetic factors and how much to differences in light intensity.” Of course, we were very interested in the morphological variation of the plants we collected, as this is one indicator of possible genetic diversity. It quickly became clear that it would be impossible to pinpoint the exact locations Thomas visited over 80 years ago. Due to some alteration of the lower forests, land use change, and uncertainty of place names, we found it all but impossible to follow Thomas’ route. Luckily Dr. Davis’ expertise paired with some local information made up for the shortcomings of our treasure map.

Dr. Davis collecting C. arabica specimens in the Upper Boma forest

The Highlights:  One of the more memorable moments of the trip was the first C. arabica plant that was spotted growing wild in the forests near the village of Rumit. This village is home to Kachepo forest people and they assured us that there was coffee ‘all over’ the nearby forest. After some time hiking around the forest behind the village, we wondered if we would ever come across this ‘abundant’ coffee. After deciding to take our trek in another direction, we were backtracking when suddenly one of our hired forest rangers alerted us of a lone coffee tree. Skinny and bare except for a few small leaves at the top of the two-meter tall tree, it stood wrapped with some dead vines and partially hidden by a larger tree. In that moment, we knew that all of our efforts had been realized. Immediately, the group switched from “hiking” mode to “coffee search” mode. In the next hour, we found and documented approximately 15 plants. It was all about tuning our senses to notice the right things in the forest. It was so easy to walk right over C. arabica seedlings. As a botanist and a Westerner overwhelmed by the whole mass of the transitional rainforest, I was of pretty much zero help picking the relatively small coffee plants out of the understory. Really, we would have been lost without our hired forest rangers and local porters, who seemed to be both familiar with the forests of the Boma region as well as the particular growth of the coffee plants.

Our indispensible local help displaying a C. arabica plant

Another day, we headed to a village called Kaiwa, home to a different tribe, the Murle people. There, we met a woman we had heard had great knowledge of the wild growing coffee plants. Her name was Nyamaron, she was conservatively over 70 years old, and was the mother-in-law of the Paramount Chief of the region. She told us that she frequently walked into the forest and collected coffee cherries or leaves for which to make a beverage with. She led us across the lower mountains and into the more dense forests on the steep mountainside about an hour away from the village, locally named the Ngelecho forest. Not long after entering the forest, she began to point out trees to us. There was a trail, but the plants were almost never right on it. This woman clearly had extensive knowledge of the region and each coffee plant, including some hanging precariously off the side of an embankment. On that particular trip we only found about five individual plants, but apparently this was because it was a very far walk to get to the region where more plants grew. Unfortunately, it was our last day in Upper Boma and we were not able to go further into the forest with Nyamaron.

Over the course of the trip, we collected leaf samples from about 75 individual C. arabica plants. Dr. Krishnan identified a possible three different populations, meaning groups of plants that were geographically grouped and could be related to each other. We also came across some locally cultivated plants in the small villages we visited in the Upper Boma region. The people in these villages informed us that they had planted these trees from seedlings found in the forest. Since we do not know the exact location that they originated, it is possible they are of different populations. We will know more after Dr. Krishnan completes her genetic and statistical analyses of the plants.

Village in the Upper Boma mountains

Big Ideas and the Next Steps: This trip was only the beginning of the WCR initiative in South Sudan. We still have many questions, but we are on the right track to begin answering them. Important to remember is that ultimately, until we have the genetic analysis of these coffee trees, we do not know exactly how ‘wild’ they are.They were certainly growing on their own and seemed unadulterated in the deep forests of the Boma Plateau, but we cannot assume that they are indigenous to (originating in) the region. Comparing markers (discrete code segments) of the genome of the plants we collected within this region and then to known cultivars and landraces, including those from Ethiopia, will allow us to understand how closely this coffee is related to indigenous landraces originating in Ethiopia. Once the plants have been analyzed for how genetically different they are from say, stock from Ethiopia, Drs. Krishnan and Davis will be able to determine more about how they fit into the phylogeny, the evolutionary history of the C. arabica> species.

Regardless of the ‘wild’ status of these populations, if they have differences from other C. arabica plants, we can rejoice in their diversity! The WCR goal of germplasm preservation is off to an amazing start with this mission. After we know more about the genetics of these plants, WCR will be able to target specific plants for a live genetic material (seed or cuttings) collection from the region, which is technically known to scientists and plant breeders as the ‘germplasm collection’. This germplasm could either be preserved through freezing or through propagation. Variety trials are another form of germplasm conservation and could be a part of the immediate future of this work in South Sudan. WCR states that evaluating the plants for yield, pest resistance, high cup quality and climate-change-tolerance will be done during the first 4 years of this project. In this way WCR and partners hope to determine if these landraces from the Upper Boma region contain any beneficial or unique traits that could be useful to the specialty coffee industry in the future.

Finally, an important area of interest lies in the potential for coffee sector development in this and other regions of South Sudan. Since we now know that C. arabica can grow on its own in this region, it may be possible to cultivate coffee there commercially in the future. As the world supply of C. arabica continues to hold steady in comparison to the demand for high quality coffee, another goal of WCR is productivity enhancement of specialty coffee. Ultimately, WCR wants to be able to increase the supply of quality coffee with greater product differentiation potential (individuality). Let’s be honest, what would be more exciting than a new origin for C. arabica in South Sudan? No pressure, WCR. We look forward to learning more about this mission as it fits into WCR goals, and the SCAA will continue to follow this project as it progresses.