Biofortification of Staple Food Crops: Six Questions

More than half the world’s population suffers from micronutrient malnutrition. Biofortification of staple food crops is a new public health approach to control vitamin A, iron, and zinc deficiencies in poor countries. Biofortification is the development of micronutrient‐dense staple crops using traditional breeding practices and modern biotechnology. It has multiple advantages: it capitalizes on the regular daily intake of a consistent and large amount of the food staples that predominate in the diets of the poor, recurrent costs are low (germplasm can be shared internationally), it is sustainable, and it can reach undernourished populations in remote areas. This paper addresses six questions: 1. Is breeding for high nutrient content scientifically feasible? There is potential to increase the micronutrient density of staple foods by conventional breeding, and micronutrient‐ density traits are stable across environments. In all crops studied, it is possible to combine the high micronutrient density trait with high yield, economically. For example, orange‐fleshed sweet potato lines with high levels of β‐carotene have been identified, and beans with improved agronomic traits and grain type and 50–70% more iron have been bred through conventional means. Transgenic approaches are in some cases necessary, or potentially advantageous, as for example, in the case of Golden Rice. 2. Will farmers adopt new varieties? The biofortification strategy requires widespread adoption by farmers. The visibility of the trait and infrastructural development are critical to adoption. Biofortified crops with visible traits will require that producers and consumers accept this change in addition to equivalent productivity and end‐use features. Crops with invisible traits do not require behavior change, and thus productivity and improved end‐use features will be important. Market networks and information flow will affect uptake once a new improved variety is released. Where infrastructure is strong, such as in Asia, uptake should be rapid; but where infrastructure is poor, such as in Africa, constraints to farmer adoption must be overcome. 3. What is the target breeding level? Retention of the nutrient following processing and cooking, bioavailability and nutrient requirements of target populations is needed to set breeding targets. For example, true retention of β‐carotene in a variety of orange‐ fleshed sweetpotato averages 80% after processing and cooking. The target level set will vary depending on whether people rely upon the sweetpotato as their sole source of β‐carotene or if they eat a mixed diet. If children and women can Biofortification of Staple Food Crops: Six Questions