Comparative Study on the Effect of Ethephon Treatment on the Growth of Two Grape Varieties Kyoho and Shine-Muscat

[Objectives] This study aimed to study the effect of ethephon treatment on the growth of two main grape varieties Kyoho and Shine-Muscat. [Methods] Two-year-old Kyoho and Shine-Muscat grape plants transplanted in the film-covered steel-framed greenhouse were used as the test materials. They were pruned horizontally and linearly. In the late growth period, the new shoots were sprayed with ethephon (1 500×). During the germination period, 10 plants were randomly selected for each variety to investigate the germination situation. Before flowering, 20 new shoots with uniform growth were randomly selected for each variety to investigate the growth. During the fruit maturity period, 10 clusters of fruits were randomly selected for each variety to determine the related indices of fruit quality. [Results] After the treatment with ethephon, the germination, new shoot growth and fruit quality differed between the two varieties. Overall, the thickness of main stem, main vine and new shoot of Shine-Muscat was greater than that of Kyoho, and the length of new shoot of Kyoho was significantly greater than that of Shine-Muscat. [Conclusions] The growth of Shine-Muscat was more robust. There was little difference in the ear weight of natural fruit setting between the two varieties. Shine-Muscat showed high sugar and low acid contents than Kyoho.