A Study On The Key Cultivation Techniques Of Second-harvest Grape In Zhejiang

Grape is one of the six major fruit industries in Zhejiang Province. In recent years, the planting area of grape has been rapidly enlarged due to significant economic benefits. Additionally, high price in May and July result in increasing planting area of promoting early-maturing grape. However, unsuitable weather such as plum rains, typhoon, early spring frost, is to blame for decreasing or even total lossing of grape production in some orchards. The second grape, which would be harvested in one vegetable recycle of grape tree, is not only make a sense for increasing yields, the most important is that it can make up for the lack of first grape and relieve the pressure of market. Based on meteorological data in recent 10 years, the grape climatic regionalization indexs include first frost date, active accumulated temperature in the growth period, hydrothermal coefficient of two months before harvesting and precipitation in mature month, were analyzed in order to research the agroclimate suitability of second grape producing in Zhejiang province. And the budbreak rate, flowering branch rate, bearing branch rate, phenological period and fruit quality of 6 different maturation grape cultivars were investigated. Those survery data were used to study the effect of different inducing methods of inflorescence differentiation in winter buds and budbreak induction time, on development and quality of second grape. Finally, the main results are as follows.l.The climatic suitability zoning of the second grape in Zhejiang Province. The first zoning includes Hangzhou, Jinhua, Quzhou, Lishui, Shaoxing and Zhoushan; the second zoning includes Huzhou, Jiaxing, Ningbo; the unsuitable zoning includes Taizhou and Wenzhou.2. Inflorescence differentiation inducing method of winter bud for the second grape. For the same cultivar, the second grape development under the method that leave 7 leaves pinching when the number of unfolding leaf is 9-10 on main shoot, is better than leaving 8 leaves pinching when the number of unfolding leaf is 10-12 in the same district. Especially the second grape bearing branch rate of ’Muscat Kyoho’ and ’Benibarad’ was up to 60%. The winter bud could be induced to break after pinching 35d.3. The best budbreak induction time of winter buds in the first axillary shoots of summer buds. Super-early maturing and early-maturing cultivars should be cut back in the August 5 to August 15 for producing winter fruits, and earlier middle maturing and middle maturing cultivars should be cut back around June 10 for producing autumn fruits. Due to the hot weather, all cultivars shouldn’t be induce winter buds break during June 10 to August 5.4. The quality of the second fruit. Except for’Muscat Kyoho’, the second grape cluster and single berry weight are significantly less than that of first grape. TSS, the content of titratable acid(except for ’Muscat Kyoho’), total anthocyanin and total phenolic in the second grape are higher than that of first grape.