Save and Grow: Cassava

9. Let farmers decide

Incorporating sustainable natural resource management into smallholder production systems requires a shift in research and extension from “teaching” to “learning”.

Cassava growers will need to be convinced that ecosystem-based “Save and Grow” farming practices are better than those they are already using, and – very importantly – that they have short-term economic benefits. It is important, therefore, that cassava growers be involved in all stages of agricultural research and technology development, and that they test and validate practices aimed at improving the productivity and sustainability of their production systems.

Chart: Mixed cropping generates higher net income than monoculture
Mixed cropping generates higher net income than monoculture

Farmer participatory research (FPR) emerged in the 1990s in response to the failure of top-down agricultural research to deliver significant improvements in the well-being of low-income farmers in risk-prone environments. The difference between FPR and the traditional “technology transfer” approach is that extension workers do not promote or recommend any particular practice or technology. Instead, they provide a menu of options that farmers can test in trials in their own fields, with help from research or extension staff.

The International Center for Tropical Agriculture has used farmer participatory research extensively in Asia for the development and transfer of cassava production technologies. With FPR, members of a farmers’ group, or farmers in a particular village or district, diagnose the main problems encountered in cassava production and consider possible solutions.

The farmers then design and conduct trials of 3 to 5 alternative treatments, along with one traditional practice. At harvest time, all farmers in the area are invited to a field day where they view the trials and discuss the results. During the field day, staff present the average results of the various types of trials, as well as the production costs, gross income and net income of each treatment. Based on this information, farmers can select those treatments that they consider most suited to their own conditions.

An independent impact assessment found that, in Thailand, 100 percent of the farmers who participated in trials had adopted improved varieties, and 98 percent the use of mineral fertilizer. In one province of Viet Nam, improved technologies and agronomic practices boosted average per hectare root yields from 8.5 tonnes in 1994, when the trials began, to 36 tonnes in 2003.

The Asian trials have also shown clearly that farmers prefer those treatments which produce both sustainable yields and the highest net income.

Farmer field schools (or FFS) encourage a process of group-based learning, and were originally developed by FAO in the late 1980s to promote integrated pest management (IPM) in Asian rice fields. At field schools, farmers are able to deepen their knowledge of agro-ecosystem processes, and test practices that control pests and diseases and improve the sustainability of crop yields.

In Africa, the spread of new strains of the viruses causing cassava mosaic disease and, more recently, cassava brown streak disease, have served as an entry point for promoting IPM and eco-friendly production. Field schools link up with programmes that distribute disease-tolerant cassava varieties and test them in multiplication fields. This learning-by-doing approach provides the opportunity for farmers to develop strategies to manage disease problems more effectively, while improving their cassava production practices.

In the Democratic Republic of the Congo, an FAO project trained facilitators to assist 30 field schools in Kinshasa province, where yields of cassava had been declining owing to pest attacks, diseases and soil nutrient depletion. Through training in the use of healthy planting material, mulching and intercropping, the field schools helped farmers achieve yield increases of up to 250 percent.

In Gabon, pest and disease pressure, the lack of improved varieties, and the use of inefficient farming methods kept smallholder cassava root yields below 8 tonnes per ha. Through field schools, some 750 growers improved their skills in the selection of healthy planting material. Many began using higher-yielding varieties with resistance to cassava mosaic disease, as well as improved practices, such as avoiding cultivation in wet soils and planting stakes along the contours of sloping land to limit damage from root rot. They also learned the importance of regular weeding, planting in rows and optimizing planting densities.

An evaluation in 2012 found that, thanks mainly to the use of high yielding varieties, IPM and resource-conserving cultivation practices, the farmers had increased their cassava yields threefold. In one province, yields reached 30 tonnes per hectare.


Save and Grow: Cassava (FAO, 2013) can be purchased from

Save and grow: Cassava - cover

Save and Grow: Cassava A guide to sustainable production intensification (FAO, 2013)
ISBN 978-92-5-107641-5
140 pp. 182 x 257 mm, paperback

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