CBSD stakeholder

CABI has joined forces with the Zambian Government in a bid to help curb the spread of devastating Cassava Brown Streak Disease (CBSD), which can lead to total loss of the crop – considered a staple food source for millions of residents.

Representatives from CABI’s centres in Lusaka and Nairobi, Kenya, met with officials from Zambia’s Ministry of Agriculture (MoA) and His Royal Highness Senior Chief Kaputa to agree work collaboratively on a plan to help fight CBSD in Zambia.

Also working, as part of a campaign to raise awareness and act against CBSD, are the Zambia Agriculture Research Institute (ZARI), Department of Agriculture (DoA) and Dziwa Science and Technology Trust (DSaT).

Dr Noah Phiri, CABI’s Regional Representative, Southern Africa, Dr Chapwa Kasoma, Post-doctoral Fellow ISM- Zambia, and Dr Ivan Rwomushana, Senior Scientist, Invasive Species Management at CABI, attended the stakeholder meeting following a CABI-published evidence note highlighting the impact of CBSD on cassava – Zambia’s second most important crop after maize.

The evidence note states that CBSD, a fairly new viral disease in Zambia, threatens the development of Zambia’s cassava sub-sector.

This includes increased demand for the tubers from Zambia Breweries, Zhongkai international, Itabwa Investments and Sun Bird International who need over 50,000 tonnes of annual cassava feedstock for brewing, mining, confectionary and biofuel production.

The document also highlights how CBSD originated from the coastal regions of East Africa close to the mid-20th century and has spread to central and southern Africa.

The exact origin of CBSD in Zambia is not certain, but being a landlocked country with eight neighbouring countries, there are speculations of the disease having originated from some of her neighbours.

CBSD, the evidence note reports, was first diagnosed in cassava samples collected from the North-western province during routine pest surveillance. Subsequently, CBSD prevalence was confirmed in Kaputa and Chienge districts at 32.3% incidence, and has since spread to other districts.

Estimated losses due to CBSD in Zambia are around 55% of total cassava production, equivalent to monetary losses of over US $500,000.

CBSD media

A media orientation event preceded the stakeholder conference on Cassava Brown Streak Disease to help journalists better report the issue affecting farmers in Zambia (Credit: Elias Chulu – MUVI TV).

The stakeholder meeting followed a training workshop aimed at Zambia’s media – of which more than 30 attended – who can play a vital role in the dissemination of information to help raise awareness amongst smallholder farmers of the issue that currently has no cure.

During the stakeholders meeting, the Minister of Agriculture Mr Reuben Mtolo Phiri said cassava ranks high among the staple foods and is a strategic crop for food security and livelihoods in Zambia. He expressed the Government’s commitment to curbing the spread of CBSD in the country together with other strategic partners at the meeting, as well as learning lessons from other countries that have successfully handled the disease.

The Minister added that more people depend on maize in sub-Saharan Africa as Cassava ranks high among the staple foods in Zambia and added that the Government is committed to helping to curb CBSD in the country.

Meanwhile, Senior Chief Kaputa disclosed that 16 camps in Kaputa are affected and that they are worried that CBSD is spreading rapidly in the province and the appeal is that experts continue with the advocacy.

The Royal highness also appealed to the Office of the Vice President to help the people of his Chiefdom through the Disaster Management and Mitigation Unit (DMMU).

Dr Noah Phiri said, “We are concerned with the arrival of CBSD. It poses a major challenge causing yield loses of up to 100 percent in susceptible varieties and has become the leading biotic constraint to cassava production in Southern Africa.

“Our work in partnership with ZARI and the Department of Agriculture and other stakeholders is vital if we are to reduce the impact of this devastating disease.”

Dr Ivan Rwomushana reiterated that Zambia, as a member country of CABI can leverage wide ranging expertise and best practices in the sustainable management of the disease, and that the PlantwisePlus programme was committed to support the farmers on this journey.

Dr Kasoma presented an update on what CABI has done so far including a survey of CBSD, and dissemination activities. She also presented the evidence note.

The CABI evidence note further reveals that farmers in the affected regions report substantial losses in cassava production due to severe hard rots in harvested roots and reduction in root quality caused by pitting and constrictions.

A 2021 survey conducted by CABI to assess the prevalence and impact of CBSD in Zambia’s traditional cassava growing regions revealed widespread root damage symptoms from 51% of respondent farmers.

Dr Kasoma also presented the Concept Note, which was validated by workshop participants. The Concept Note outlines what needs to be done to provide availability of, and access of farmers to clean cassava planting materials.

Veronica Mwaba, Founder and Director of DSaT, speaking at the training workshop for journalists, said, “Many jobs will be lost especially those that rely on cassava, hence the need for us to make a follow up on the steps that are going to be taken to save the cassava crop in Zambia as it is cultivated on our soil.”

Ms Mwaba said she is keen to hear from researchers regarding new and improved ways to prevent CBSD as well as how to manage it to stop further damage to crops.

The campaign to raise awareness moving forward will include farmer gatherings, plant health rallies, SMS and radio shows.

The meeting also agreed on a response plan to curb the spread of the disease, including better diagnostics, phytosanitation at the farm and community level and the development of a seed system to ensure farmers can get access to improved and disease-free planting materials. CABIs PlantwisePlus will seek to support Zambian farmers towards the attainment of the Country’s vision to manage the CBSD menace.


Additional information

Main image: Stakeholders who met to discuss how to mitigate the impacts of Cassava Brown Streak Disease in Zambia (Credit: Joseph Banda – Digital Media).

Cassava Brown Streak Disease Evidence Note

The evidence note ‘Cassava Brown Streak Disease (CBSD) An Evidence Note on Impacts and Management Strategies for Zambia’ is available to read online here:

Relevant blog

See also the blog ‘Evidence note highlights impacts and management strategies for Cassava Brown Streak Disease in Zambia.’


The work on management of CBSD in Zambia is a major component of CABI’s PlantwisePlus programme. PlantwisePlus is supported by contributions from the UK Foreign, Commonwealth and Development Office, the Swiss Agency for Development and Cooperation, the Netherlands Ministry of Foreign Affairs and the European Commission (DG INTPA).

We express sincere gratitude to our partners, ZARI and the DoA of the Ministry of Agriculture in Zambia, in our concerted effort to manage CBSD in Zambia.