A new seedless table grape cultivar Biyu

Abstract: Biyu is a new seedless grape cultivar selected from the crossing of Jingxiu×Red Globe in 2006. Through artificial crossing technology, 665 seeds were got in 2006 and sowed in 2007. It was ini-tially selected in 2010 for its good appearance, good quality and strong adaptability. After regional adaptability trial in different sites, it was finally selected in 2018. We applied for the registration as a new cultivar and got identification certificate from the Forest Fine Cultivar Examination and Approval Committee of Gansu province in 2020. Biyu has moderate growth vigor and the mature canes are yel-low-brown and the average length of internodes is 6.2 cm. The leaves are near round and have five cracks and smooth. The cultivar has hermaphrodite flower and the first inflorescence is usually borne on the 3rd or 4th node. The bud eye germination rate was 75.4% and the bearing cane rate was 85.2%.The average number of panicles per fruit cane was 2.0. The inflorescence is conical-shaped and the bunch weight is 278.5 g averagely with the length and width being 16.2 cm and 12.5 cm, respectively.The berry is green-yellow in color and near round shape, average weight is 3.7 g, and the longitudinal diameter and transverse diameter are 1.82 cm and 1.78 cm, respectively. The berries are soft with mid-dle juice and pleasant sweetness and sourness. The content of soluble solids is 20.6%, the average total sugar content is 16.10%, the average total acid is 0.52% and the average vitamin C is 3.92 mg·100 g^-1.The time from bud break to leaf fall stage is about 195 d, and the berry maturity date is at late August in Lanzhou area. The cultivar has some good characteristics including early-ripening fruit, high and stable yield, and strong disease and cold resistance. The young vines in the second year after planting can bear berries, and in the third year they will reach the full bearing stage, also within four years, the yield will reach 14.5-16.0 t·hm -2. After comprehensive screening, the planting spacings are 1.5 m between vines and 3 m between rows, respectively. In order to produce high quality fruit, the cultivar uses the Y shape frame and short spur pruning technique. The cultivar is productive, so fertilizer and water management should be strengthened. Meanwhile, nitrogen-phosphorus compound fertilizer was applied after berry  setting, and potassium fertilizer is reasonably used during color- turning and berry expansion period. The grape clusters should be sprayed with spectroscopic fungicides before bagging, and then bagged after the liquid was dried. For prevention of pests and diseases, the control of downy mildew, powdery mildew and gray mildew should be focused by taking steps with combining with the physical and chem- ical control technology in vineyards. Biyu has a wide adaptability, which can be cultivated in the most areas of Gansu province.