Fig. 6. Dawn to dusk trends in mean leaf net assimilation rate (A) of fully expanded sunlit spring wheat leaves for day after 50% emergence (DAE) and development stages given for 5 d during the (a–e) 1993 and (f–j) 1994 growing seasons. Measurements were simultaneous with and sampled as described for g_s in Fig. 2. Symbols in legend, source of variance, and results from ANOVA same as described in Fig. 1. The above illustration was derived from measurements of as many as 3540 leaves.