The literature on innovation in agriculture is dominated by two approaches: the induced innovation model and what might broadly be termed a political economy or ‘institutional’ analysis. In the 1980s, however, two major developments, one on the supply side and the other on the demand side, have radically altered the context of innovation in all sectors of the agro-food system. The traditional organisation of the food system around specific crops and product complexes is thus being undermined by changing technologies and shifting demand patterns. The efficiency of biocatalytic fermentation, an ancient method of food and drink production, promises to be enhanced in several ways by genetic engineering. Recent acquisitions of seed firms and plant genetic research companies by large chemical and pharmaceutical corporations represent a important dimension of the restructuring of the agro-food system by biotechnologies. The potential of biotechnologies to transcend species barriers is accompanied by a related capacity to overcome industrial barriers to entry between hitherto separate sectors.