International agricultural research is often motivated by the potential benefits it could bring to smallholder farmers in developing countries. A recent experimental literature has emerged on why innovations resulting from such research, which often focuses on yield enhancement, fail to be adopted due to either external or internal constraints. This article reviews this literature, focusing on the traits of the different technologies and their complexity and distinguishing between yield-enhancing, variance-reducing, and water- or labor-reducing technologies.
More than 250 million Africans rely on the starchy root crop cassava (Manihot esculenta) as their staple source of calories. A typical cassava-based diet, however, provides less than 30% of the minimum daily requirement for protein and only 10%–20% of that for iron, zinc, and vitamin A. The BioCassava Plus (BC+) program has employed modern biotechnologies intended to improve the health of Africans through the development and delivery of genetically engineered cassava with increased nutrient (zinc, iron, protein, and vitamin A) levels.