Figure 9.

Theoretical (○) and measured (●) hydraulic resistance of a single maize leaf as a function of the leaf length (including the sheath). The leaf was progressively cut back from the tip and the resistance was recorded after each cut. The leaf parameters for the theoretical curve were: R_x = 6.0 × 10⁴ MPa s⁻¹ kg⁻¹ m⁻¹ and R_m = 4.5 × 10⁴ MPa s⁻¹ kg⁻¹ m⁻¹ and a stalk plus node resistance of 1.68 × 10⁴ MPa s⁻¹ kg⁻¹. The R_x and R_m values of the leaf sheath had to be set to 1.8 times the values for the leaf blade to fit the last two points.