Fig. 1. An example of leaf net assimilation (A) vs. photosynthetic photon flux density (PFD) for experimental plots that were either irrigated the previous day (wet) or that were not irrigated the previous day (dry). Wet and dry data sets were collected on three or four leaves on 8 and 11 Aug. 2003, respectively. Error bars are ± standard error. Regression curves are of the form y = y₀ + a[1 – exp(–bx)] with R² > 0.99 for both curves.