Incident radiation, fraction absorbed, and total absorbed radiation for each source.

The absorbed radiation was normalized to a PPF of 1000 µmoles per m2 per s for each radiation source. This does not result in exactly equal PAR (in watts per m2) because of spectral differences among radiation sources. The total absorbed radiation for each source is shown in bold. Leaf temperature was held constant at 25°C. Net longwave exchange with lower leaves or surfaces was assumed to be zero.