Figure 4.

Vertically resolved, diurnal differences in absorbed PPFD (ΔPPFD_A; A and B), net photosynthetic CO₂ assimilation (ΔA; C and D), and the quantum efficiency of CO₂ assimilation (ΔΦ_CO2; E and F) between a mutant with reduced chlorophyll content (Y11y11) and wild-type before canopy closure early in the growing season (DOY 193 LAI = 2.7: canopy A, C and E) and at peak LAI (DOY 230 LAI = 7.5: canopy B, D and F). Color map shows the difference between Y11y11 and wild-type canopies (Y11y11, wild-type values) at each of the vertical canopy regions above ground normalized by the canopy height (z/h). Positive values (yellow/red) represent regions of the canopy where Y11y11 has a larger value than wild type, and blue values are regions where the wild-type values are higher. The two selected days were both cloudless and received similar amounts of total downwelling radiation (Supplemental Fig. S5). Wild-type and Y11y11 canopies were parameterized using genotype-specific chlorophyll contents and leaf area indices. Values are expressed on a ground area basis. WT, wild type.