Scientists have developed a way of creating ‘fruit-tree portfolios’ that help farmers grow a range of trees that produce nutritious foods, improving their intake of important micronutrients.

In much of the world, the achievement of dietary recommendations is falling short and will continue to do so unless strategic interventions are made to transform agricultural production to include a greater diversity of readily available, nutritious foods.

The need to focus much more on food quality through ‘nutrition-sensitive’ agriculture has increasingly been recognised in global policy frameworks and commitments. Within this new agenda, increasing tree cultivation has an important role to play because around 74% of fruits produced globally are harvested from trees, which also produce nutritious leafy vegetables, nuts, seeds and edible oils.

Moreover, the deep and extensive roots of trees make them more tolerant to drought than annual crops, meaning they can provide food in dry periods when other sources are not available. Tree foods have, thus, the potential to complement and diversify the predominantly staple-based diets of rural households through the year.

‘A sufficient intake of fruits can alleviate micronutrient deficiencies and reduce the risks of associated diseases,’ said Stepha McMullin, lead author of a study on the subject published in Food Security journal. ‘In many parts of sub-Saharan Africa, however, the production and consumption of fruits are inadequate on average and, in particular, in specific seasons.’

To better incorporate fruits into local food systems and meet the challenge of seasonal availability, McMullin and team from World Agroforestry (ICRAF) developed a methodology based on ‘fruit-tree portfolios’, which selects in partnership with farmers the fruit-tree species for production that are suitable socio-ecologically and important nutritionally. The study was conducted under the Fruiting Africa and Food Trees projects, both funded by the European Commission and International Fund for Agricultural Development.

The approach involves a variety of scientific tools, including surveys and discussions with farmers, that allow triangulation of data sets. It also provides an example of how agriculture can be used to promote nutritionally-rich foods, particularly, for smallholders who rely predominantly on food from their own farms.

The research team found that the portfolio approach can be adapted to different locations with diverse agro-ecological conditions, as illustrated by the varying environments of three sites they studied in Kenya. The tools applied were flexible enough to develop portfolios for each site that were unique, owing to variations in species’ suitability, fruit-tree phenology and farmers’ preferences.

The portfolios could also be designed to include intra-specific diversity by promoting different varieties of fruit species with offset harvest seasons. For example, mango — rich in vitamin A and highly favoured by farmers and consumers —has several early- and late-maturing types that could be grown to extend seasonal availability.

The portfolios can help reshape local food systems to contribute to national and global goals on nutrition, such as Sustainable Development Goal no. 2: ‘End all forms of malnutrition by 2025’.

The approach makes use of location-specific data to not only capture the socio-ecological dynamics of smallholders’ food-production diversity but uniquely includes individual food-consumption data to better understand dietary gaps. Such individual-level consumption data are imperative for making informed decisions at country, regional and global levels but available information is often limited.

For example, the data available are often based on national food supplies rather than individual-level information disaggregated by location, gender, age and intra-household food allocation. A key point identified by the authors of the Global Nutrition Report 2017 was the need to fill this gap in the data. In the portfolio approach, the research team did this at context-specific, local levels in Kakamega and Siaya counties, Western Kenya and Machakos County, Eastern Kenya.

‘Our study has demonstrated a methodology that can be applied to varying contexts, highlighting the relevance, and the need to make use of, location-specific data’, said McMullin. ‘In forthcoming applications, the approach could be strengthened by including individual food-consumption data at different points in the year to capture seasonal production variations and other time-dependent patterns and by monitoring inter-seasonal stability in fruit-tree phenology. This would support stronger recommendations for species that target year-round gaps in harvests and nutrients in local diets, building greater resilience into production systems.’

The information gathered using the portfolio approach can also complement global initiatives to collate data and make it publicly available through platforms such as the FAO/WHO Global Individual Food Consumption Data Tool.

Download the journal article

McMullin S, Njogu K, Wekesa B, Gachuiri A, Ngethe E, Stadlmayr B, Jamnadass R, Kehlenbeck K. 2019. Developing fruit tree portfolios that link agriculture more effectively with nutrition and health: a new approach for providing year-round micronutrients to smallholder farmers. Food Security. https://doi.org/10.1007/s12571-019-00970-7. pp 1–18.

This story was produced with the financial support of the European Union and IFAD. Its contents are the sole responsibility of World Agroforestry and do not necessarily reflect the views of the European Union and IFAD.

World Agroforestry (ICRAF) is a centre of scientific and development excellence that harnesses the benefits of trees for people and the environment. Knowledge produced by ICRAF enables governments, development agencies and farmers to utilize the power of trees to make farming and livelihoods more environmentally, socially and economically sustainable at multiple scales. 

ICRAF is one of the 15 members of the CGIAR, a global research partnership for a food-secure future. We thank all donors who support research in development through their contributions to the CGIAR Fund.