Sustainable intensification of smallholder farming is a serious option for satisfying 2050 global cereal requirements and alleviating persistent poverty. That option seems far off for Sub-Sahara Africa (SSA) where technology-driven productivity growth has largely failed. The article revisits this issue from a number of angles: current approaches to enlisting SSA smallholders in agricultural development; the history of the phenomenal productivity growth in the USA, The Netherlands and Green Revolution Asia; and the current framework conditions for SSA productivity growth.

This paper takes the viewpoint of a social scientist and looks at agricultural scientists' pathways for science impact. Awareness of these pathways is increasingly becoming part and parcel of the professionalism of the agricultural scientist, now that the pressure is on to mobilize smallholders and their productive resources for (global) food security and for reducing persistent rural poverty. Significant new thinking about pathways is emerging and it is useful to present some of this, even if it is not cut-and-dried.

Rural extension is a process of work and accompaniment with the producer aimed to sustainable development of their skills. In Mexico, a series of extension models have been adapted, that goes from the US, implemented in the early 1980’s, to the hub model or innovation node (platform - demonstration module - extension area) applied since 2010 under the MasAgro Program. The aim of this paper is to analyze the various processes of extension in Mexico.