I recently came across a 2007 article I had saved from the New York Times. In the article titled, Africa, Prosperity from Seed Falls Short, Celia Dugger wrote about the merits of the New Rices for Africa, or Nericas. ”The seeds are a marvel producing bountiful, aromatic rice crops resistant to drought, pests and disease.” She continued however to describe a situation many improvers face “But a decade after their introduction, the seeds have spread to only a tiny fraction of the land here in West Africa where they could help millions of farming families escape poverty.” We often think reaching everyone who would benefit from an intervention or service is a matter of getting individuals to make the decision to adopt the change. Quite the contrary in West Africa, there “you have farmers who are very willing adopters of new technologies and want to raise yields.” To help diagnosis the problem, it is important to understand that to achieve improved performance at scale you need to consider methods for both spread and scale-up. Spread is focused on methods to increase the rate individuals adopt changes. Scale-up is focused on methods to identify and overcome the structural issues that arise as changes are adopted. When it comes to use of new rices, it is not a spread problem. “Villagers enviously spotted the new rices growing in a neighboring community’s field”. That was enough for them to make the adoption decision. The problem in West Africa is one of scale-up. Ms. Duggar wrote “getting access to seed, fertilizer and small-scale irrigation… is the holy grail of agriculture development” and so overcoming these structural issues is the constraint to wide use of new rices. Most improvers will need to spread and scale-up interventions to achieve their aims so, in future postings, more on the methods to do that and the connection to testing and implementation.