Bacterial wilt (Ralstonia solanacearum) is a serious disease of potato. It can be managed with cultural practices, but only if farmers understand the technologies, and the reasons behind them. Face-to-face extension methods, like farmer field school (FFS), can teach these messages to smallholders, but other methods may also be useful. This paper compares FFS with two less- costly methods: “community workshops” and radio, and presents follow up surveys of these three extension methods. Community workshops were almost as effective as FFS for teaching most ideas; radio spots were less effective, especially for ideas that require demonstration, but they reach a much larger audience. The three extension methods gave the most different results for time-consuming technologies, where a more compelling demonstration may convince farmers to adopt a task that adds work to an already busy day. Extension methods should be chosen for the particular context. The more complicated, tedious, and counter-intuitive a new technology is, the more important it may be to use a more intensive extension method and the less likely that a mass media will be successful.
Keywords: Bolivia, Brown Rot, Extension, Ralstonia solanacearum, Training