African food security: research on climate resilient potatoes taking root

Professor Torrance in Sub-Saharan Africa

Half of the countries in Sub-Saharan Africa have a poverty rate higher than 35%. Of the many factors that contribute to such a concerning statistic is the increasingly unreliable rainfall of countries such as Kenya and Malawi due to climate change, an issue that will only worsen. Professors Lesley Torrance and John T Jones, of the School of Biology, have been addressing this concern by applying their research on stress biology and disease diagnostics to the development of stress resilient and early maturing varieties of potato. 

Potatoes are crucial to global food security, a measure of the availability and accessibility of food. They are rich in fibre and many of the vitamins needed for a healthy life, including C and B6, while also being fat free. Potatoes also benefit food security because they are a source of income and employment; in Kenya there are 800,000 potato farmers and more than 2.5 million people employed in the potato value chain. Unsurprisingly, then, potatoes are designated as a key food security crop by the governments of Kenya and Malawi. However, the existing varieties of potato that are farmed – in Malawi 70% of the crop is produced from just two varieties – yield only a quarter of the crop obtained in other countries. This is partly due to low input potato systems, a shortage of disease-free seed and high pest and disease incidence. To produce tubers, potatoes require the cooler night-time temperatures found in the highland regions (>1500 masl). The work on heat tolerance done in this research has allowed the development of potato genotypes that can be grown more widely outside the highland regions.  

Torrance and Jones’ research has the potential to greatly impact the agriculture of Sub-Saharan Africa, mostly because they have focused on understanding the needs of its potato farmers. They found that farmers need potatoes that grow quickly to meet consumption demands, and that cook quickly to reduce fuel costs. By incorporating this knowledge into their plans, Torrance and Jones were able to ensure their research had the maximum positive impact. Added to these criteria was the need for the new varieties to be more heat tolerant, to enable more widespread growth in warmer regions climates, and resistance to pathogens such as Potato Virus Y (PVY). 

The QuickGro team in Malawi 

Of the 60 potato varieties initially trialled by Torrance and Jones, twelve were found to successfully combine all the desired traits. These twelve were introduced to Sub-Saharan Africa in 2019, and within the subsequent year they had been grown in new areas of Kenya and Malawi with considerable success. The Zomba District Agricultural Development Officer agreed when he wrote that ‘Heat tolerant potatoes were liked by farmers and will be beneficial to extend production to warmer regions such as Zomba’, ‘early maturity will enable rotation with other crops’, and ‘moving production to new areas will benefit farmers economically’.  

The introduction of new varieties is only the latest stage of what has been a long-established and sustained series of projects. In 2014, for instance, Torrance and Jones introduced to Kenya the Mayan Gold variety, which saw huge demand due to its virus resistance and quick cooking time. The same year, they introduced four new varieties to Malawi that had a 53% yield advantage over existing varieties.  

Not only have Torrance and Jones introduced new varieties of potato to Sub-Saharan Africa, but they’ve improved the existing stock. This work included a clean-up and return of tubers of the ‘Violet’ and ‘Rosita’ varieties in Malawi, which together comprise 70% of the planted crop. This initiative was combined with a drive to improve inspection standards for potato stock, which involved collaboration with multiple regulatory bodies to conduct a training programme in Malawi for more than 50 technicians and government inspectors, and eventually the development of a region-wide response to new crop pests in Kenya at the invitation of its government.  

Torrance and Jones’ work with potato genotypes has impacted the agricultural sector of Sub-Saharan Africa on multiple levels. From the introduction of new, stronger varieties tailored to the specific needs of local farmers, to the strengthening of existing varieties and inspection procedures, their impact has been invaluable to the fight against poverty in the region. Their work has improved local efforts to achieve food security, poverty reduction and economic growth, giving their research a truly nation-wide impact. 


This work contributed to the University of St Andrews’ REF 2021 submission.

The Research Excellence Framework (REF) is a system which assesses research at UK Higher Education Institutions by discipline, based on three elements: outputs, impact and environment. This blogpost is based upon an impact case study that contributed to St Andrews’ outstanding results this REF cycle. Visit REF to view the submitted case study in the UKRI’s impact case study database.


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