‘Shuguang 8’，a new Chinese jujube cultivar with large fruit and high resistance to fruit cracking

Abstract: ‘Shuguang 8’, a new local jujube cultivar with big-fruit, bud mutation and resistance to fruitcracking was selected from‘Jinsixiaozao’resources of Cangzhou, Hebei province. It was initially selectedin 2008 for its early bearing, big fruit, resistance to fruit cracking, high and stable yield, etc. After sixyears regional adapt ability testing a three sites (including Xianxian, Cangxian and Qingxian) from 2009 to2015, it was finally selected in December 2015 and named‘Shuguang 8’. The fruits are long oval and bigshape with 34.87 cm in length and 29.29 cm in diameter, whose leaf color is deep green with a thicknessof 0.38 m, the ratio of length and width is 1.76. The average fruit weight is 14.02 g, it is 2.16 times to thatof the check variety. The jujube stone is flat spindle with weight of 0.49 g. The jujube stone is small, hav⁃ing a wine-colored peel, and flesh texture is loose, succulent, with a pleasant sweet flavor during crispripe period. The edible rate is 96.47%, and the dried rate is 52.1%. The soluble solid content reaches29.99%, the titratable acid and the vitamin C content of fruit are 0.32% and 4 230 mg·kg-1, respectively.The whole growth period of jujube is 95-110 days, the average number of inflorescence and fruit is 2.9per branch, 6 years after grafting, the average yield of‘Shuguang 8’is 27.9 kg. Experimental results showthat the resistant ability of fruit cracking is strong, and only 8.7% of fruits is dehiscent in contrast withcheck variety, which is 58.6% in the same growing period. So it is a good variety not only for flesh butdried eating. In Cangzhou, it ripens in late September, and it is suitable for high and stable yield, fitting toplant the jujube trees in Hebei and Shandong province. In other parts, we can introduce to plant it. Itadapts to sand soil, loam, clay soil and so on, the suitable soil pH range for tree growth is in 5.5-8.2. Itcan be normal growth when the soil salinity is 0.3% and annual precipitation is 400-700 mL. The condi⁃tions of establishment garden are flat land, open terrain, plenty of light, fertile soil, in addition to the goodirrigation and drainage conditions. We can take multi head grafting technique in the top-grafted big trees,usually the trees are open-center shape or the small and sparse canopy shape, the pruning way are mainlybranch-thinning, branch-pulling and so on. The florescence of‘Shuguang 8’is long, we can spray oncejujube flower and fruit protector to improve fruit setting rate when it suffered by continuous high tempera⁃ture weather during florescence. The main pests on jujube trees are jujube red-spider, Apolygus lucorum,Chihuo zao Yang, Peach Fruit Moth, Carposina niponensis Walsingham, Asias halodendri and Euzopherabatangensis Caradja, the main disease on jujube trees are jujube rust, dehiscent fruit disease and Macroph⁃oma kuwatsukai. We can select the high-efficiency, low toxicity, low residual pesticides and the other bio⁃logical agents to pest control and prevention.