Promising Crop Biotechnologies for Smallholder Farmers in East Africa: Bananas and Maize

In contrast to cross-breeding, genetic transformation allows for enhancement of one trait in a variety while retaining other desirable traits or attributes. Host varieties can be hybrids bred by scientists or endemic types maintained by farmers. Varieties that are popular among farmers are those whose traits or attributes are appreciated by farmers. Inserting a gene into a host variety that is already popular among farmers will increase the transgenic variety’s chances of being successful. The large number of distinct banana varieties grown on farms in Uganda suggests that insertion of transgenes into more than one background will be necessary for generating a broad-based impact on the productivity of the banana sector. Scientists at the National Agricultural Research Organization (NARO) have identified several varieties for initial transformation assays in order to represent the range of genomic and use group diversity found among clone sets in Uganda. Each transformation event, however, has an associated cost. In addition, transforming too many varieties within one genomic group could contribute to genetic uniformity for the trait and vulnerability to pathogens that overcome the resistance imparted by the genetic transformation. Choices will need to be made about the host variety or varieties into which the transgene will be inserted. In turn, the choice of host variety will affect the distribution of benefits among communities and farmers within communities. This point can be illustrated using an economic model to analyze the determinants of farmer demand for planting material from seven potential host cooking-banana varieties and then generate two pieces of information related to demand. Taking Nakitembe—the most widely grown variety in the major banana-producing areas of Uganda—as an example, first, client prototypes are identified by comparing the characteristics of farm households with high and low predicted demands for the variety. This exercise illustrates how the choice of host planting material can have social consequences. Second, changes in total industry demand for planting material of a genetically transformed host variety are simulated (a) when resistance traits are inserted, with varying degrees of effectiveness, and (b) when other supporting public investments are made in extension, market infrastructure, and education. The simulation demonstrates how the magnitude of the payoff resulting from research investment depends crucially on other types of investments. About the Authors Svetlana Edmeades is a postdoctoral fellow in the Environment and Production Technology Division of the International Food Policy Research Institute (IFPRI).