Organizations intending to introduce new crop technologies to farmers might benefit from the findings of a new study of HarvestPlus’ project to introduce vitamin A orange sweet potato (OSP) in Africa. That project, Reaching End Users (REU), promoted OSP in Mozambique and Uganda between 2006 and 2009, leading to OSP adoption rates of over 60 percent among project households and nearly doubling average dietary intake of vitamin A.

The new study attempts to tease out the factors responsible for the REU’s impact in both countries and highlights the role of farmers’ access to OSP vines that they plant afresh at the start of the growing season. “Several factors including nutritional information and other demand creation activities play important roles in getting farmers to adopt a new crop. The most important contributor that we found in this instance was vine access,” says Daniel Gilligan, one of the study’s authors.

Despite varying socio-economic conditions between Mozambique and Uganda, the study found strikingly similar results in the contribution of vine access to OSP adoption and consumption in both countries. “We were able to compare across interventions and across countries and speak to which component of the intervention was more cost-effective. We quantified the contributions of each of the pathways to improving intakes,” notes J.V. Meenakshi, another co-author.

The study adds to the growing literature on constraints to adoption of worthwhile agricultural technologies. For organizations involved in or planning on promoting such new technologies, the findings can inform decision making on which pathways to strengthen for maximum impact. For other researchers, the data sets on which the study’s analysis is based are now available at

HarvestPlus, which expanded operations to promote OSP in Uganda following the REU pilot continues, with funding from USAID, to invest in strategies to improve farmers’ access to vines. These include expanding the network of vine multipliers, and promoting new methods, such as the Triple S technology which allows farmers in drought-prone areas to produce planting material from OSP roots. HarvestPlus is also working with local tissue culture labs to ensure that OSP vines that are distributed to farmers are free of viruses. Nearly 300,000 Ugandan households are currently growing and eating OSP.

For a summary of the REU project, download the brief.

Additional Resources 
Farmers Speak: Orange Sweet Potato (video)