Advancing biotechnology to solve Africa’s food challenges

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As temperatures rise and rainfall patterns change, global plant disease outbreaks are increasing, posing a huge threat to agriculture. Africa, home to 50% of the world’s smallholder farmers, is particularly vulnerable.

Climate change has propelled the spread of a banana fungal disease, just one of many plant pandemics. “We're living on borrowed time,” says Wijnand Swart, a plant pathologist at the University of Free State (UFS) in South Africa. “We're only just discovering what can happen when temperatures reach extremes. Stressed plants are susceptible to secondary opportunistic pathogens, and climate change creates opportunity for new diseases which previously didn't affect plants.

“Coffee, rice, yams, cassava, pumpkin, and wheat are some of the staple crops that will be affected.”

Besides pathogens, there are grave concerns about the vectors that carry them. Swarms of insects are flying to warmer areas, carrying viral diseases with the potential to wipe out entire crops. “Humans are also vectors, carrying spores on their shoes and clothes, making biosecurity the most critical issue,” adds Swart.

Pest outbreaks have increased in frequency, and are responsible for up to 40% of maize, potato, rice, soybean, and wheat crop yield losses worldwide, according to the Food and Agriculture Organisation of the United Nations (FAO). It is a catastrophic situation in a world where food insecurity is already the reality for more than 800 million people.

“Few institutions in Africa are equipped with the resources and human capacity to undertake disease diagnosis and management,” says plant geneticist Eric Danquah, the founding director of the West Africa Centre for Crop Improvement (WACCI). “Despite the technologies, research, and products to help agriculture to maintain integrated management and farming practices, pathogens continue to significantly reduce crop productivity.”

Technological potential

There has been some advances in monitoring systems which have boosted capacity for disease diagnosis. “As far back as 15 years ago in Uganda, someone could take a photo of a plant, send it to a central centre, and get a disease diagnosis. There's excellent research being done in places like South Africa, Kenya, Uganda and Rwanda by researchers who are at the cutting edge of science, but because of a lack of resources and constraints in rolling solutions out to communities, we can't compete with the US and Europe,” he says.

He’s excited about developments, such as widely available apps that can distinguish between similar pathogens, that are leading the way in plant disease technology.

But for him, the future of plant pathology will be the ability to monitor diseases via drones and the use of computer science to monitor soils and predict which crops are at risk of disease.

“There’s also crop pharmacology, where we design fungicides to fight new diseases, find beneficial bacteria that can give plants an advantage, and create designer-made organisms to protect plants from disease,” he says.

Danquah has advocated for science to improve farmer’s lives for decades. In 2018, he became the first African to win the World Agriculture Prize, and is a strong advocate for the benefits of biotechnology.

“Agriculture remains the largest contributor to Africa’s economy, employing two-thirds of the workforce and contributing 20-60% of GDP. However, it faces huge challenges, including low productivity, water scarcity, loss of soil fertility, pests and diseases, post-harvest losses and has the least chance to adapt to climate change shocks”, he says.

Danquah says genetic engineering “can assist breeders to develop crops that better adapt to the threats of climate change.” GM crops like the nitrogen efficient, water efficient and salt tolerant (NEWEST) rice can protect crop yields as global temperatures increase.

He’s confident that with biotechnology, more plants can be modified to adapt to the climate crisis, including desertification, changing rainfall patterns, and an increase in pests and diseases.

Swart cautions that biotech will save yield losses, but smallholder farmers who can't buy into biotech may be left behind. “Imagine what smallholder farmers would be able to achieve with a bit of technology? But getting it to them is the problem.”

Missed opportunity

It’s a view supported by the Africa Union Development Agency-New Partnership for Africa's Development (AUDA-NEPAD). “Biotechnology is a powerful tool to modify genetics in crops and animals that would otherwise be impossible through classical breeding. Harnessing this offers Africa an unparalleled opportunity to circumvent a range of challenges in crop and animal agriculture,” says Jeremy Ouedraogo, head of AUDA-NEPAD’s biosafety programme.

But this remains a challenge. It’s nearly three decades since commercial planting of biotech crops began, but the global genetically modified organism (GMO) footprint remains relatively small. Only 29 countries grow GMO crops, while 43 import them for food feed, and processing, according to ISAAA.

In 1998, South Africa became the first African country to plant biotech crops, beginning with insect-resistant cotton, followed by maize and soybeans. Only six other African countries have approved GM crops: Sudan, eSwatini, Ethiopia, Malawi, Nigeria and Kenya. It is under development in 11 other states.

Sudan, Malawi, and Nigeria grow GM cotton, while field trials of several other GM crops — cassava, cowpea, banana and Irish potato are taking place in Mozambique, Kenya, Uganda, Ghana, Burkina Faso and Rwanda.

These countries belong to the Open Forum on Agricultural Biotechnology (OFAB), established by the African Agricultural Technology Foundation (AATF) in 2006 as a platform for advancing stakeholder interactions on agriculture biotechnology, and supported by AUDA-NEPAD.

Useful regulatory systems are essential to the future of agriculture. “The delay in the rollout in biotechnology is due to several factors”, says Hennie Groenewald, executive manager at Biosafety SA. “We’re still having the same tired conversation about the safety of GMO when it has been proven to be safe and sustainable, so even when countries have the scientific expertise, the bureaucracy of establishing a regulatory framework is an obstacle.”

Ouredraogo points to “a lack of political will as the overriding factor, a lack of appropriate regulatory tools such as biosafety laws, and a lack of functionality because of inappropriate provisions, even when the regulatory tools are in place.”

Groenewald says the high cost of commercializing a commodity product in South Africa presents a major hurdle. Only large agricultural biotechnology companies have the adequate resources, and have little incentive to produce local crops for the benefit of smallholder farmers.

This monopoly has also led to a ‘lack of public trust due to exploitation by multinational companies’, says Ouedraogo.

Danquah offers a more optimistic perspective. “GM technology is increasingly becoming more accessible and less expensive, allowing the development of GM crops at reduced cost with the seeds made available as a public good and not-for-profit to farmers”, he says. He cites the work of scientists from the International Potato Centre (CIP) who have bio-engineered four locally-grown potato varieties in Uganda, Kenya and Rwanda, with three resistance (3R) genes that are “virtually 100 percent resistant to blight”.

Biotechnology advances

Plant pathogens are a significant challenge in agriculture despite efforts to control them. Bacteria and viruses continue to evolve to cause more devastating effects.

Biotechnology has moved far beyond GMOs, with CRISPR-based genome editing considered one of the most powerful technologies for producing crops that are more drought resistant, can fight weeds and disease, and produce bigger yields.

“One of the most effective and sustainable ways to manage plant pathogens is to use genetic modification and genome editing to expand the breeder’s toolkit. We also have transgenic plants that carry sequences derived from plant viruses. We cannot afford to ignore the new solutions that genetic modification provides to manage plant pathogens,” says Danquah.

Far more precise than the foreign transfer of genes, CRISPR/Cas9 is a tool that can be used to precisely cut and remove or replace a specific genetic sequence.

There are currently several gene-edited plants under development; notably bananas, cassava, maize, sorghum, wheat and yam that are both food and cash crops for smallholder farmers.

Ouedraogo is excited about their potential, and the yield advantages of genetic engineering over non-biotech crops. “Heat stress, drought and flooding induced by climate change affect agricultural production, reducing both the quantity and quality of agricultural produce. Modern biotechnology has shown its worth by minimising or totally avoiding the impacts of such stresses,” he says.

“Now we have banana crops resistant to bacterial wilt, pod borer resistant cowpea, and maize hybrids developed by integrating insect resistance and drought tolerance genes.”

But while several countries, including the US, UK, China, and Argentina, have eased regulations for gene-edited crops, only Eswatini, Kenya and Nigeria have published biosafety guidelines for the regulation of gene editing. In 2021, South Africa classified genome-edited plants as genetically-modified crops.

“We want to support sustainable innovation, but we'll only be able to harness the potential for small scale farmers if there's better infrastructure, and more locally relevant crops, that will bring down the cost,” says Groenewald.