Fig. 1.

Midday photosynthetic gas exchange measurements taken at the respective growth [CO₂] for ambient (plain bars) and FACE (cross-hatched bars) treatments (390 and 590 µmol mol⁻¹, respectively). Koshihikari (KH) is shown in the white bars and Takanari (TN) in the gray bars. Data are from the 2012 and 2013 field seasons. The measurements were taken at the following growth stages: (1) booting (approximately 1.5 weeks before heading); (2) full heading (3 d after heading, 2013 only); (3) early grain filling (GF) stage (1 week after heading); (4) mid GF stage (2 weeks after heading); and (5) late GF stage (4 weeks after heading, 2012 only). All measurements were taken on flag leaves. Error bars are SEMs. Different letters above each bar indicate significant differences between means at α = 0.05 within each measurement time point. n = 4. (A) Net photosynthetic carbon assimilation rate (A). (B) Stomatal conductance to water vapor (g_s).