Tillering is generally recognized as one of the most plastic traits affecting accumulation of biomass and ultimately grain yield in many field crops. Kim et al. (pp. 69–78) study five hybrids of Sorghum bicolor, derived from a common genetic background and with similar phenology and plant height but contrasting tillering. They find that genotypic differences in tillering are associated with differences in the carbon supply–demand balance within a plant, and the results provide avenues for phenotyping mapping of populations to identify genomic regions regulating tillering.
