Fig. 1. Average transmitted irradiance for an alfalfa crop under clear skies on DOY 195 at an LAI of 4.2 (40° solar zenith angle) and at an LAI of 1.0 (20° solar zenith angle) for sample numbers 1, 5, 10, 20, and 40. (a) PAR; (b) UV-A; and (c) UV-B. Error bars are shown for the average transmitted irradiance.