Based on a collective research project designed to analyze the links between scientific and technological production, development and democracy in Latin America, this paper deals with the performance of the agrarian economy under conditions of scant internally generated technology. We begin by acknowledging that this resource has historically been imported. We frame the objective of analysis in terms of assessing its economic and social implications through an empirical approach to the process of technological diffusion. Two representative experiences of the agricultural structure are examined in the region, namely, peasant productive units in Mexico and capitalist enterprises on the Argentine plains. For the former, we look at the post-war era, examining the content of the technological package contained in the green revolution and its repercussions. In the latter case, we look at present-day agro-business and analyze the propagation of the transgenic soybean known as “Roundup Ready” in the pampas region. In both cases, we consider the positive and negative characteristics within the productive and macroeconomic order, including impact on employment, environment, and social welfare.