Abstract: The experimentwas conducted with Royal Gala apple trees, and the effect of fruit bagging on
leaf net photosynthesis was analyzed. L ight and CO₂ response curves and daily change of photosynthesis in
leaves of fruit-bagged tree were studied. Results showed that bagging had no effect on the photosynthesis of the
leaves on the exterior canopy. But it reduced the maximal net photosynthetic rate and CE of the interior leav2
es. At the same time, bagging also could make a weaker light environment for the interior canopy, and short
ened the effective time of leaf photosynthesis. W ith fruit2bagged trees, the maximal Pn value of leaves in the
interior canopy was 16.5 μmol·m^-2 ·s^-1 , only 68% asmuch as the control. The daily average Pn value of
the leaves on fruit-bagged tree was 5.25 μmol·m^-2 ·s^-1 , significantly lower than that of the control, thus
decreasing the ability of carbon assimilation. So, the weakness of photosynthetic capability in interior leaves
could be refered to as one of the reasons thatmaking fruit-bagged quality to become worse.

Key words: Apple, Bagging, Net photosynthesis