Apparent quantum yield of photosynthesis of double cropping rice in red earth hilly region of China

The photosynthesis rate-light response curve of double cropping rice in the red earth hilly region is a non-rect-angular hyperbola function．The average values and standard deviations of the apparent initial quantum yield of flag leaf，second leaf and third leaf from the top are 0.0536±0.023，0.0511±0.023，0.0488±0.025，respectively．That is，they descend gradually from the flag leaf to the lower leaves．The optimal temperature of photosyn thesis of rice in this area iS from 27℃ tO 30℃ ．