2.5. Measurement of dry weight
Flower spikes were divided into four portions: basal 30-cm stem, flowers from the basal 30-cm stem, the remaining upper stem that was a newly grown portion after harvest, and flowers from the remaining upper stem. The tissues were dried at 80 C in an oven for three days and their dry weight (DW) was measured.Three spikes were used in each experiment, and experiments were repeated three times.