Murang’a: Poor management and control of common coffee diseases are to blame for poor production and low quality of cherry. A plant pathologist working with Coffee Research Institute (CRI) Getrude Alworah has said farmers have to intensify efforts in combating two most destructive diseases that have been affecting coffee production in the country.
According to Kenya News Agency, Alworah spoke during the Coffee Farmers Open Day held in Murang’a on Saturday, highlighting coffee berry disease (CBD) and coffee leaf rust (CLR) as prevalent issues that have significantly reduced coffee yields and compromised cherry quality. The event gathered agricultural experts, researchers, and coffee stakeholders aimed at equipping farmers with strategies to curb the spread and impact of these diseases.
Alworah detailed that coffee berry disease, caused by the fungus Colletotrichum kahawae, affects developing berries, resulting in black lesions and premature fruit drop. The disease thrives in cool, wet conditions, particularly during the flowering and early fruiting stages, and is a primary cause of low yields among Arabica coffee growers in the country.
To address CBD, Alworah recommended the planting of disease-resistant coffee varieties such as Ruiru 11 and Batian, developed by CRI to withstand fungal attacks. She mentioned that these varieties not only minimize losses but also require fewer chemical inputs, making them suitable for both small- and large-scale farmers. She also emphasized the importance of timely and proper fungicide application, advising farmers to apply copper-based fungicides before rain, when the disease is likely to spread.
Alworah stressed the significance of following the correct fungicide dosage and seeking professional guidance for effective results. Regular pruning and canopy management were also highlighted as crucial measures, as overgrown coffee trees with dense foliage create humid conditions conducive to fungal growth. Farmers were urged to prune coffee bushes regularly and manage shade trees to enhance airflow and sunlight penetration, naturally suppressing disease development.
Field sanitation was noted as equally vital, with Alworah encouraging farmers to maintain clean coffee fields by removing fallen berries, pruned branches, and other plant debris that may harbor disease-causing organisms. Proper disposal of infected plant material reduces the chances of reinfection and disease persistence in subsequent seasons.
Regarding coffee leaf rust (CLR), caused by the fungus Hemileia vastatrix, Alworah warned that it was increasingly common, especially in lower altitude areas. CLR manifests as orange-yellow powdery spots on the underside of coffee leaves, leading to premature leaf fall, reduced photosynthesis, and lower yields. Similar to CBD, using resistant varieties like Ruiru 11 and Batian is one of the most effective ways to manage CLR.
Alworah explained that high humidity, often due to excessive shading, encourages the spread of rust spores. Farmers were advised to manage their shade trees properly by thinning and pruning them to lower humidity and allow sunlight to reach the coffee plants. Weekly farm inspections were recommended for early disease detection, enabling quick action such as removing affected leaves or applying targeted treatments before infection spreads.
She urged farmers to utilize training and extension services, work closely with local agricultural officers, and attend forums like the coffee expo for continuous learning. The event was seen as a timely intervention, especially as climate change continues to make coffee bushes more vulnerable to diseases. With the right knowledge and practices, farmers now have renewed hope in restoring productivity and protecting the future of Kenya’s coffee industry.