One of the biggest challenges is to ensure food security in the face of a dramatic increase in the world population and climate change. Yield in temperate cereals as barley and wheat is determined by a combination of different traits, among these are number of spikes, number of grains per spike and the size of the grains. These traits are negatively regulated, so that an increase in one of these traits often results in the decrease in other traits. Thus, yield increases become more difficult to achieve. Recent insights into the genetic and molecular regulation of meristem development suggests that the same genes or regulatory modules can regulate the development of different shoot meristems. For example, genes that regulate inflorescence development also control the development of axillary shoots, and thus tiller and spike number. By combining novel technologies such as single-cell sequencing with genome editing and transgenic approaches we will identify new potential targets regulating specific meristems in barley. This knowledge will allow us to modify developmental processes to break pleiotropy and to improve yield.