Effects of different concentrations of mepiquat chloride on grape’s second crop

Effects of different concentrations (Drug multiplier was 0,750 and 375 times) and the application amount per 667 m2 (0, 40, 80 g） of mepiquat chloride on grape’s second crop were studied with summer black, yellow rose and black rose grape. Result showed that the second flowers of each grape variety and the number of fruiting branches on grape side shoot enlarge as the application amount per 667 m2 of mepiquat chloride enlarge Mepiquat chloride has a promoting effect on grape’s second crop, and the treatment with 250 g/L mepiquat chloride 375 times can increase the rate of fruiting branch and flowers on each branch significantly. The fruiting branches of summer black, yellow rose and black rose are 61.52%, 91.11% and 50.44% respectively after using 250 g/L mepiquat chloride 375 times. The second flowers on each branch of summer black, yellow rose and black rose are1.60, 2.04, 1.04 respectively after using 250 g/L mepiquat chloride 375 times. Yellow rose and summer black are sensitive to different concentrations mepiquat chloride. It is suggested that using yellow rose and summer black as materials, and artificial topping combining chemistry topping to form a year of two harvest cultivation of grapes in Guangdong.