Development and promotion of biological control approaches for management of coffee berry disease

Coffee Berry Disease (CBD) is an anthracnose caused by Colletotrichum kahawae Bridge and Waller. It is the major disease of Coffea arabica in Africa. It infects all stages of the crop from flowers to ripe fruits and occasionally leaves, but highest crop losses occur when green berries are infected resulting to the formation of dark sunken lesions with sporulation which causes their premature dropping and mummification. It destroys the coffee seed which is the economic part of the crop. Every year, farmers in coffee growing countries in Africa incur crop losses of up to 80% due to CBD if proper management is not done.

In implementing this project, my main aim will be to develop strategies and recommendations of using Biological Control Approaches (BCAs) to promote sustainable coffee production. I will divide the project into 4 main objectives that I will implement over a period of 3 years; to identify Biological control agents of CBD and determine their distribution in space and time, determine the effectiveness of the potential BCAs in control of CBD, determine the field efficacy of screened BCAs on the severity and incidence of CBD, and to upgrade and package the BCAs into applicable products and promote them among farmers. 

I will isolate potential BCAs from soil and plant materials sampled from 300 small scale farms, a representative sample of the 63,000 small scale coffee farmers in Kirinyaga, County in Kenya. The first activity will be to identify the isolated BCAs to species level. I will then characterize the mode of control of the BCAs against CBD using laboratory bioassays. In the laboratory I will also determine suitable formulations, effective concentrations and dosage for the BCA products. This will then be followed by field trials to determine the field efficacy of BCAs, effect on non-target organisms such as other plants, pollinators and other beneficial organisms. In order to have final usable products, I will collaborate with a development partner to formulate and package the BCAs as well as train farmers and create awareness on the effective use of the BCAs.

Successful implementation of this project will benefit the over 700,000 small scale coffee farmers, medium and large coffee estates in Kenya. The products developed will also be available at affordable prices for use by coffee farmers across Africa whose trees are susceptible to CBD.

This project has been partly funded by the Kenyan Government through the National Research Fund. However, the funds received are not enough to fully implement all the objectives. The received funds are being used to implement the first three objectives.So far the activities for the first objective have already been done. We have so far isolated and identifiedEpicoccum sp, Bacillus sp, Penicillium sp and Trichoderma sp as potential antagonists to Colletotrichum kahawae. The organisms were isolated from plant and soil samples collected from 300 coffee farms in Kirinyaga County, Kenya. They were identified using morphological and microscopic techniques and then were evaluated for antagonism against CBD in the laboratory.

At the end of the study, I will have achieved the following: documentation and publication of a checklist of bio control agents for controlling CBD, publication of spatial temporal distribution maps of CBD and BCAs, documentation of mode of action of identified BCAs on CBD, product application information will be generated, sustainable and effective biological control products will be developed, patented and recommended to farmers. Additionally, I will publish 4 papers in scientific publications, my PhD thesis, develop BCA training kits, and contribute to policy briefs.

I am passionate about coffee and its sustainable production due its economic importance and contribution of the sector to poverty alleviation. In Africa coffee is produced in Eastern, Central and parts of West Africa with the largest producer being Ethiopia followed by Uganda, Tanzania and Kenya. In Kenya an estimate of 170,000 Ha of land is under coffee production and is highly characterized by cultivars of Coffea arabica such as SL28 and SL34 which are susceptible to CBD. Coffee plays a key economic role in Kenya contributing up to 20% of the total hard currency. From the total 70% of Kenyans engaged in Agriculture, 30% are employed in the coffee sector. Coffee production in Africa has been declining over the past decade. This is mainly attributed to losses due to insect pests and diseases a situation that has been aggravated by changes in climate. Coffee Berry disease is mainly controlled by heavy and prolonged use of chemicals which are expensive, toxic to non-target organisms, pose risks to human health as well as cause soil and water contamination. Management of CBD has proven challenging due to the ever increasing cost of crop protection products (developing a single molecule will cost approximately USD 200,000 a cost that is usually transferred to farmers), and development of fungicide resistance by C. kahawae as reported in Central Kenya.

There are several successful biological control approaches implemented in other crops across the world. However, in coffee it is still novel with a few cases under research being reported. For instance, the fungus Beauvaria bassiana is used in south Central America to manage coffee berry borer. In Africa studies on biological control of coffee pests are very limited and currently there is no biological control approach for CBD. Biological control is very compatible with integrated pest management strategies aimed at reducing negative effects of chemicals. Biological control could reduce pesticide residues in green coffee, accumulation of chemicals in the environment, mortality of non-target organisms and effects of chemicals on human health. Therefore, there is a dire need to develop disease management strategies that are sustainable and environmentally safe; which can only be achieved through a thorough understanding of the biology and ecology of the BCAs.

I am carrying out this project as my PhD project at the University of Nairobi. Awarding me these funds will go along way in successful completion and attainment of my doctoral degree. To the farmers, bio-control options may be cheaper and sustainable especially if applied as live organisms and are able to establish in the coffee farms. Development of locally available products will be cheaper thus reducing the cost of crop protection and production as a whole. Biological control is compatible with organic farming and interested farmers will be able to produce coffee for specialty niches which will pay premium prices for their coffee thus increasing farmersโ€™ profit margins. Use of these products will contribute to mitigation of climate change as some of the chemicals currently used contain active ingredients that emit greenhouse gases.

Getrude Okutoyi Alworah, Kenya


  1. This is a very good innovative aproach to combating CBD.If succesful it will safe our environment from the massive quantities of chemicals we us to control this disease every year


  2. This is the way to go, i wish there would be more ways to fund this so that it can even go further to roll out to the small scale farmers.


  3. This is very timely and highly sustainable. It is an idea whose time has come. I know you have all the intelligence and will power to execute it. We are with you and behind you the whole way


  4. A brilliant idea to combat one of the most critical crop disease in Kenya. Go go go and claim our heritage- coffee from CBD.


  5. Very informative…well-done my dear Gertrude!!
    Keep soaring higher and stop at nothing until this solution reaches all coffee farmers World Wide….


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