After the first plant started to flower, daytime temperature was reduced to 28–29◦C (control conditions) in order to avoid pollen sterility. All plants were harvested at full maturity (at the completion of seed filling) and number of tillers, panicles and seeds as well as seed set (an estimated % of panicle filled with seed), above-ground fresh and dry mass (g) per plant were measured. Tiller numbers were also recorded 2 and 6 weeks after the heating as indicated in the text. Dry mass was taken after drying all above ground biomass for 1 week at 30◦C until completely dry. The LER were measured in the second week after heating began, using a linear variable displacement transducer, essentially as described . Five individual plants from separate blocks were measured at varying times of the diurnal cycle.