Despite a huge population increase since the 1960s, the green revolution more than doubled world grain production and averted large-scale famine. Food crop productivity will have to be further raised, however, because the world population is still increasing rapidly. Among several parameters associated with the increase in yield potential, genes that control plant height and tiller number (in cereal crops) have recently been identified. In addition, a promising strategy to generate semi-dwarf varieties has been developed. Recent advances in plant genome analyses and plant biotechnology will realize a second green revolution through the genetic engineering of food crops.