Kenyan Researchers Develop Disease-Resistant Cassava Variety to Boost Crop Yield

Kenya Agricultural and Livestock Research Organisation (Kalro) scientists have successfully developed a genetically modified cassava variety that is resistant to two major diseases: Cassava Brown Streak Disease (CBSD) and Cassava Mosaic Disease (CMD). This breakthrough, achieved through modern technology, offers promising solutions for farmers struggling with low and poor cassava yields due to these diseases. The disease-resistant cassava variety will soon be released into the market, providing hope for improved productivity.

Collaborating organizations involved in the research include Virus Resistant Cassava for Africa (Virca Plus), University of Nairobi, International Service for the Acquisition of Agri-Biotech Applications (ISAAA), International Institute for Tropical Agriculture (IITA), and several other non-governmental organizations. These partners united their efforts to combat the challenges posed by CBSD and CMD, which have been causing significant crop damage and reduced yields for Kenyan farmers.

Cassava is a vital food crop in Kenya, particularly thriving in the arid and semi-arid areas that make up approximately 80 percent of the country’s land mass. It is the second most important staple after maize in the Coastal and Western regions. Cassava’s resilience during droughts, when alternative food sources are scarce, makes it crucial for food security. However, the prevalence of CBSD and CMD has hampered farmers’ efforts to attain optimal yields.

CBSD is transmitted between plants by whiteflies and through infected cassava cuttings. Infected cassava roots develop brown lesions, rendering them unfit for human consumption or animal feed. Severe CBSD infections can lead to complete loss of usable cassava storage roots. The new disease-resistant cassava variety, however, holds the potential to prevent up to 90 percent of crop damage, significantly improving yields and the availability of marketable cassava roots.

Recognizing the pressing need for a reliable solution, Kalro initiated the development of this disease-resistant cassava variety. After multiple cropping cycles, field tests, and extensive safety studies conducted over five years, Kalro submitted an application to the National Biosafety Authority (NBA) in 2019 for the environmental release and open field cultivation of the CBSD-resistant cassava. The application received approval in June 2021.

The next crucial step involves national performance trials conducted by the Kenya Plant Health Inspectorate Service (Kephis) before the new cassava variety can be registered and made available to farmers. Although an exact release date is yet to be determined, Prof. Douglas Miano, the lead scientist at Virca Plus Kenya, assures that it will be in the near future.

Since 2011, researchers have been growing and evaluating disease-resistant cassava in three diverse locations across Kenya: Mtwapa, Kandara, and Alupe. Kalro Mtwapa serves as an experimental site due to its high incidence of CBSD and CMD. Kalro Kandara is designated for regulatory and breeding trials, being a disease-free location. Alupe is utilized for yield and trait selection trials.

Several national agencies are jointly working towards the final stages of research on the new cassava variety. The National Environmental Management Authority monitors any potential environmental impacts, the NBA assesses food safety aspects, and Kephis focuses on the suitability of planting materials when the disease-resistant cassava is eventually released to farmers. Dr. Catherine Taracha, Director of Kalro Biotechnology Centre, affirms that the new variety will increase production and contribute to the realization of the anticipated flour-blending policy, which aims to address nutritional challenges in Kenya.