Understanding the adoption of root, tuber and banana crops in sub-Saharan Africa

Background

There is a constant need for plant breeders to develop new, high-yielding varieties to meet the many challenges of climate change, pests and diseases, soil depletion and changes in consumption patterns. Breeders also need to consider post-harvest characteristics that affect storage, transport and processing. However, insufficient knowledge about decision-making by actors in root, tuber and banana value chains has resulted in some new varieties receiving low levels of acceptance and uptake. Suitability for processing, for instance, is a key issue that has so far been generally neglected in agricultural research.

This project will improve knowledge and understanding of the essential quality traits that promote widespread adoption of roots, tubers and bananas throughout their value chains. The project is coordinated by the French Agricultural Research Centre for International Development (CIRAD) in collaboration with the International Potato Center (CIP) and other international research centers, as well as national agricultural research systems in target countries.

Objectives

The project seeks to improve the likelihood that highyielding clones with enhanced tolerance to biotic and abiotic stresses will be combined with quality traits that meet user expectations. The key objectives are to:

1. define the key user-preferred quality traits for a range of root, tuber and banana food products (including potato and sweetpotato) through conducting surveys with endusers;
2. link these product profiles with biophysical and functional properties of root, tuber and banana products, and develop laboratory-based methods to assess these properties in a quantitative manner;
3. develop high throughput phenotyping protocols for rapid screening of user-preferred quality traits in new varieties; and
4. integrate key user traits into breeding and variety deployment programs.

Approach

The key crops under study are banana, cassava, potato, sweetpotato and yam. Multidisciplinary teams bring together specialists from social sciences and food technology to capture essential traits through surveys conducted with farmers, traders, processors and consumers. The team then studies traits that are important for processing, including the size of roots and ease of peeling, hardness and suitability for grating, performance during the cooking process, quality of flours and doughs, and smoothness of pastes and purées.

Key quality criteria identified through surveys and diagnostic tests are analyzed, with the work organized into five work programs. The first looks at biochemical composition and structure, with the second program characterizing the chemical compounds of interest by developing specific methods for biophysical analysis. Based on these primary quantitative analyses, scientists build databases to establish predictive equations and calibrate phenotyping protocols in program three. In the fourth program, suitable laboratory procedures select the varieties most likely to contain the required traits, using quantitative trait loci, genetic association analyses, and other techniques that reduce the standard cost of phenotyping. Finally, in program five, the most promising clones will be tested under field conditions with prospective end-users.

The project is designed to complement ongoing investments in many other variety improvement programs being undertaken by CIP and other development organizations, and to enhance their impacts.

Expected outcomes

The project will collate new knowledge on traits and preferences for 12 root, tuber and banana products in seven countries across sub-Saharan Africa. The team will develop standard operating procedures for the analysis of these crops and relevant processed products, establishing a database of the relevant metabolites and nutrients, as well as protocols for recording texture, cooking quality, fermentation, etc. It will also produce an operational platform that can be adopted by project partners and other stakeholders to screen for the traits preferred by end-users.

Using these standard laboratory protocols, scientists will be able to evaluate suitable germplasm for the required traits and gain a better understanding of the inheritance of these traits and how to develop breeding programs to improve them. Consequently, breeding programs will be able to release varieties that include the relevant traits, thus ensuring breeding is responsive to the needs of actors along the whole value chain.

In addition, the program will encourage knowledge development and sharing, creating a community of practice among scientists that will enhance future collaboration and ensure continuity into the future.