The paper analyses the evolution of maize production during the last two decades in southern Mali, a region known mainly for its cotton. Maize production actually took off during the first half of the 1980s as a result of a voluntary programme bringing together technical support, effective input provision and a guaranteed price under compulsory state-controlled cereal trading. In 1986, while adoption of intensive maize cropping was in progress, the implementation of structural adjustment policy, through cereal market liberalization and abolition of input subsidies, at first led farmers to return to traditional intercropping with decreased fertilizer use. Maize has again been providing an increased contribution to food security, from the beginning of the 1990s and in particular after the 1994 currency devaluation. Farmers are adopting more intensive maize single cropping at the expense of millet and sorghum. Our case study emphasizes the need for long-term assessment of the impact of technical innovations, along with changes in market incentives. State market control has helped introduce technical innovations which farmers readopt after market liberalization, provided input provision remains effective.