RTB: Root and Tuber Innovations for Better Harvests and Livelihoods

CIP is the lead center of the CGIAR Research Program on Roots, Tubers and Bananas (RTB) and most of CIP’s work is planned and reported through RTB, which brings together diverse partners to jointly conduct research, develop solutions, and share knowledge across crops and centers. The spirit of cross-crop learning and collaboration that lies at the heart of the program has enhanced the research for development of CIP and an array of partners.

For its second phase, which began in 2017, RTB has placed more emphasis on scaling the technologies and approaches that research centers develop. This is spearheaded by the program’s Flagship Project 5 on ‘Improved Livelihoods at Scale,’ which is facilitating the design and implementation of strategies for scaling innovations to achieve the greatest possible impact. 

Sweetpotato vine distribution in Rwanda. Improving farmer access to quality planting material is one of RTB’s areas of cross-crop research.
A grant from the RTB Scaling Fund is helping CIP and partners take the Triple S method to scale in Ethiopia and Ghana.

One of the mechanisms created for this is the RTB Scaling Fund, which in 2017 awarded its first grants to three teams of scientists as part of a broader effort to help take promising innovations to scale. Grantees included a team led by CIP researcher Margaret McEwan that is working on a method for conserving sweetpotato roots to produce planting material.

Known as Triple S, which stands for ‘Storage in Sand and Sprouting’, the method involves storing sweetpotato roots in sand during the dry season and planting them in seedbeds six to eight weeks before the rains are expected, which allows farmers to produce enough vine cuttings to plant when the rains resume. Triple S has been successfully tested in varied agroecologies and used by farmers across nine sub-Saharan African countries. CIP and partners are using the RTB Scaling Fund grant to train trainers and run gender-responsive mass media campaigns with the aim of getting 45,000 farmers in Ethiopia and Ghana to take up the technology.

Seed system toolkit

The difficulty of producing sweetpotato vines for planting in areas with long dry seasons is indicative of obstacles that root and tuber farmers face in obtaining or maintaining quality planting material. Root and tuber crops and bananas are clonally propagated, meaning farmers plant tubers, suckers, stalks, or vine cuttings, which are commonly referred to as ‘seed’. This presents several challenges for farmers, including low seed multiplication rates, bulky and perishable planting material and rapid seed degeneration, which leads to low crop yields.

Cassava stalk distribution in Nigeria. Clonally propagated crops present common seed challenges for smallholder farmers. Photo: IITA
Graphic of farmer potato transactions in Ecuador produced through impact network analysis.

“Because these crops share similar challenges and opportunities, a method or technology developed for one can often be used for another crop,” said CIP researcher Jorge Andrade-Piedra. He explained that RTB consequently brought together scientists from different research centers and disciplines to work on seed issues. “RTB facilitated the creation of an informal community of practice where we came up with common research questions that led to the development of cross-crop approaches.”

Jorge and Margaret led collaboration by researchers from all the RTB centers to develop a seed system toolkit. Those tools enable practitioners to understand and systemically diagnose problems in clonally propagated seed systems and determine how to effectively intervene in them. In 2017, technologies from that toolkit began to be validated in 14 projects with RTB crops, in Asia, Africa and South America.

One of them, a gender-responsive, cross-crop seed system framework, has been used to assess the effectiveness of rapid-multiplication technologies for seed potato production in Africa and to identify bottlenecks in potato seed systems in India. The framework is also being used to analyze sweetpotato seed systems in Ethiopia, farmer sourcing of cassava planting material in Nigeria, and banana planting material in Uganda, among other research.

Another tool, ‘impact network analysis,’ has deepened researchers’ understanding of farmer seed exchange networks and how they facilitate the spread of pathogens. A survey to estimate the structure of the networks of farmer seed and ware potato transactions in Ecuador allowed researchers to identify priority nodes for disease monitoring and training in disease management.

“It is great to see CIP scientists so engaged with RTB, contributing across our full range of crops. Many RTB seed system interventions have been suboptimal, but since there was no systematic framework for comparison or intervention design, few lessons where drawn on what works. I thus expect that the seed system toolkit will be widely used in RTB and beyond. It’s going to save time as researchers can draw on existing tools rather than develop their own, and by building an evidence of what works, it should broaden the impact from seed system interventions,” said Graham Thiele, RTB Director.

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