Selection of Grape Varieties Suitable for Double Cropping a Year in Northern Greenhouse

With the development of the greenhouse grape cultivation area,the supporting greenhouse grape varieties appear to be single.At present,there are few researches on the selection of grape varieties suitable for two-harvest-a-year cultivation in greenhouses.In order to meet the needs of fruit growers for the diversity of greenhouse grape varieties,experimental studies had been carried out.Through three consecutive years of two-harvest-a-year production of six grape varieties of‘Jingxiangyu’,‘Ruidukemei’,‘Xiangfei’,‘Jingyan’,‘Zaomanao’and‘Hanxiangmi’,the first crop of greenhouse grapes matured from May to July,and the second crop matured during the New Year s Day and Spring Festival.Through the investigation and analysis of their phenological periods,fruit economic characteristics and economic benefits,it was found that the four varieties of‘Jingxiangyu’,‘Ruidukemei’,‘Xiangfei’and‘Jingyan’performed well under greenhouse cultivation conditions,and thus can be used as supporting fine varieties for large-scale promotion.