In the past, I worked in complex humanitarian interventions, supporting farmers to reestablish agricultural production as soon as possible. But my frustration grew at our apparent inability to implement more sustainable approaches. In my current position at the International Potato Center (CIP), we collaborate with government and non-governmental organizations (NGOs) to support the distribution of sweet potato vines of the nutritious beta carotene-rich orange-fleshed varieties. With climate change leading to unpredictable rainfall patterns, droughts can become cyclical, so farmers often struggle to maintain their vines after the initial distribution. Repeated distribution of vines is not sustainable and undermines efforts to build resilience. Triple S (storage in sand and sprouting) is a root-based approach for households to conserve and multiply planting material from one season to the next.

In Tanzania, women farmers living in areas with a long dry season have praised the Triple S technology. They can spend a long time searching for vines at the start of the rains. Triple S allows them more control over access to vines and timing for planting.

Triple S builds on farmer practice and is particularly important in areas with a long dry season.

• Farmers select healthy roots to store in layers of sand in a container, which may be an old plastic basin, or purpose-built pit.
• Over the dry season, farmers monitor the roots, removing any rotten ones and de-sprouting if necessary.
• Six to eight weeks before the start of the rains, farmers plant out the sprouting roots in a seed bed and irrigate.
• By the time the rains start, farmers have good quality vines for planting.
• Over three harvests, each seed root can produce 30-40 cuttings, so 100 seed roots (stored in sand in two small basins) can produce an estimated 12,000 cuttings, enough to plant almost 0.4 hectare of field.

With support from the CGIAR Research Program on Roots, Tubers and Bananas (RTB) Scaling Fund, we have worked with partners in northern Ghana and southern Ethiopia to develop and implement a scaling strategy. Triple S PLUS is an innovation package used to scale the innovation.

Components include:

• Good agricultural practices.
• Use of different types and sizes of storage container.
• Local multiplication and sales of planting material.
• A multimedia gender responsive communication strategy for training and extension to encourage the uptake of Triple S.

In northern Ghana, large international NGO nutrition-sensitive agriculture programs distributing sweet potato planting material incorporated Triple S as part of their strategy to ensure sustained access to improved orange-fleshed sweet potato varieties. They have used demonstrations, videos and radio programs to teach male and female farmers how to use Triple S to conserve planting material from one season to the next and to have sufficient planting material at the start of the rains.

Better quality planting material planted earlier will contribute to improved yields for food and income.

In southern Ethiopia, Ayelech Alemu Tefera explained, "Triple S has become very important for us; it helps us to keep our sweet potato planting material and is good as a source of income. We have been trained about this technology by CIP. We know how to set up Triple S, how to select the roots to differentiate between healthy and rotten roots. We have become experts in the technology and we are eager to work on a large scale. Our only concern is marketing."

This underlines the need to ensure that enabling market and policy conditions are also considered when thinking about scaling a technology.

In Mozambique, we have seen how post-flood and -cyclone recovery efforts can provide an opportunity for the dissemination of improved, nutritious sweet potato varieties. Triple S goes one step further to ensure that if farmers like those varieties, they have the knowledge and skills to conserve them.