Effects of Ground-covering Reflective Film on Coloration and Quality of Kyoho Grapes

  Objective  Effects of placing a sunlight-reflecting film on the ground on the coloration and quality of Kyoho grapes were studied.

  Method  In a rain shelter at Xiaosong Town, Jian 'ou City, Fujian, 3-year-old Kyoho grape vines were cultivated. In between rows, a silver-white aluminized plastic film was placed on the ground starting from the initiation of fruit color change till maturity. Effects of the film application on color of the grapes on upper and lower parts of a bunch as well as the anthocyanin content, longitudinal and transverse longitudes, shape index, as well as the contents of soluble solids, sugars, and total acid of the fruits during the ripening process were monitored.

  Results  The ground-covering reflective film hastened the grape color formation, evened the color development of individual fruits on a cluster, and significantly increased the anthocyanin content in the peel. The firmness of the grapes increased by more than 67.30%, while the individual fruit weight rose by more than 26.79%. A uniform typical oval or oblong Kyoho grape shape was obtained on the vines. Although a slight increase on the soluble solids in the fruits by the film application was observed, it was not significant.

  Conclusion  Covering ground with the reflective film 30d prior to fruit maturation significantly facilitated Kyoho grape vines in achieving the desirable uniformity on fruit color development and shape formation in a rain shelter. In addition, the application significantly increased anthocyanin content in the peel that could materially intensify the color enhancing the visual and bioactivity quality of the grapes for marketing.