Scientists treated cassava as the crop you ate when everything else failed. A Sierra Leonean breeder named Alfred Dixon spent his career making it the crop you planned for. Cassava already fed hundreds of millions of Africans. It grew on poor soils and survived drought. What it could not survive was mosaic virus, bacterial blight, and yields too low to carry a growing city. The first high-yielding, mosaic-resistant Tropical Manioc Selection lines had been released at the International Institute of Tropical Agriculture in Ibadan in 1977, under S. K. Hahn. The plant was fixed in the plot. It still had to be fixed for the farm. Dixon took over the cassava programme in 1994. Colleagues started calling him Dr. Cassava. He coordinated improvement across West, East, Central, and Southern Africa and is credited with more than 400 varieties bred for different soils, seasons, and cropping systems. Nigeria later renamed one of its top releases, formerly TMS 980581, Dixon. He also pushed the unglamorous half of the work: seed systems, so farmers received clean stems instead of a research paper. He did not replace the staple Africa was already growing. He bred the one in the field until it could carry the harvest.