Tech to the rescue of cassava in Sub Saharan Africa

In Africa, where an estimated 300 million people rely on the tuber as a primary food source, the effects of especially two diseases, the Cassava mosaic disease and Cassava brown streak disease, have been more pronounced and devastating, as witnessed in stunted plants and barren lands. The diseases render the plants inedible and unsellable, causing up to 100 percent yield losses. Farmers are also forced to destroy the crops to tame further spread of the disease. 

Traditional interventions have not been effective. The whiteflies, for example, have been developing resistance against chemical weapons. To test the diseases and the new variants, scientists, grappling with limited testing capacity, have been taking samples of the ‘sick plants’ abroad for analysis with results taking months to arrive, at which point it becomes too late to rescue the crop.

But technology is now coming to the rescue of farmers and crops in the form of a portable DNA sequencer that detects any disease in a record 20 minutes, allowing scientists to recommend timely interventions like the planting of resistant varieties. It has made a significant difference in saving farms and more than doubling of yields. 

Dubbed MinION, the innovation has been introduced in East Africa by scientists working under the Cassava Virus Action Project.

The initiative that is working to invest in the capacity of local scientists to embrace technology to find low cost and rapid solutions to solve the needs of smallholder farmers in Sub Saharan Africa has so far trained over 350 scientists from Kenya, Uganda, Tanzania, Democratic Republic of Congo and Sierra Leone.  

The project chose to specifically focus on cassava as the pilot crop, because compared to other high calorific crops like maize, it can withstand difficult weather conditions like drought and produces relatively high yields. This makes it an ideal crop that can be used as a source of calories, especially when unpredictable weather patterns affect production of cereal crops.

“A lot of advancements have been made in the past few decades in molecular technologies. We are now moving from an era where DNA sequencing had to be done in big laboratories that are expensive to set up and maintain to portable devices that allow for DNA/RNA extraction and sequencing at point of need,” said Brenda Muga, a scientist working under the Cassava Virus Action Project. “In the cassava project, for example, we are able to identify the various virus strains in the field and then [advise] the farmers before we leave. As we increasingly embrace these technologies, African scientists will transform the continent by solving some of the age old problems, especially on food that needs urgent interventions.” 

The success of the project in reaching rural farmers and bringing technologies that address their problems to their doorsteps has demonstrated the pivotal role science and technology continue to play in focusing on the underserved population, with solutions that may have hitherto taken time and processes to reach them, which further fans existing problems. This is particularly true in agriculture and food systems in the developing world, where pests and diseases are blamed for up to 40 percent of food losses.

“Growing demand for food is a key driver for innovation and technology. By using innovations like the ones we are working with, we are able to ensure that farmers are informed early enough on the threats so that they do not have to wait six months only to realise that they have lost their yields given that sometimes the plants do not show symptoms despite the roots being affected,” Muga added. “Technology is a key component in all aspects of food production from the use of drones for precision agriculture, mobile apps for providing information on when to apply different practices and even to point farmers to available markets.”

Dr. Laura Boykin, a biologist who works with genomics and supercomputing to tackle farmers’ problems and who has collaborated with the East African scientists in the cassava project, maintains that in order for technology to have real impact it has to be placed in the hands of those who understand the problems and are passionate about solving them, a philosophy that has guided the cassava intervention.

“The reason this project has been successful is because it has always been about the people. It has been driven by African scientists. We have built a lot of capacity for young African scientists and democratised technology by placing it in the hands of those who need it the most, those that are solving real problems,” she said. 

With a target of reaching 10 million farmers in 2025, the cassava project is now looking at building the capacity of more African scientists, while sequencing other crop diseases and pests, including potato, maize and rice. 

“Genome Sequencing is crucial in understanding viruses and diseases. It has been relied on by scientists to understand diseases like Ebola and recently the emerging COVID-19 strains,” said Dr. Boykn, adding that, “it is hard to understand genomes if you do not do sequencing. That has been the same concept in understanding these viral diseases in cassava and our mission is to replicate this to other crops in order to address one of the largest contributors of food insecurity in Sub Saharan Africa.” 

Image: Eco-livelihoods.