As it was expected, when 0.5 mmol L−1CA solution was applied at 30 DAFB, the russet formation of ‘Golden Delicious’ apple was significantly inhibited since the young fruit stage (Fig. 2). In fact, we tried CA concentrations including 0.05, 0.5 and 5 mmol L−1in 2012, and found that all concentrations had significant inhibition while 0.5 mmol L−1was the most effective. In 2013, we tried more narrow concentrations from 0.14 to 0.71 mmol L−1, and the results turned out that 0.56 mmol L−1was the most effective (data not showed). Thus, we believe that CA concentration at about 0.5 mmol L−1 is the best in inhibiting fruit russeting of ‘Golden Delicious’ apples