‘CN 13’, an early ripening nectarine cultivar

‘CN 13’comes from multi-generation crosses between Chinese landrace nectarine, introducedforeign nectarine and Chinese white peach cultivars. 94-1-47, the female parent, is a middle-season,white-flesh, freestone nectarine with middle acid.‘CN 4’, the pollen donation, is an early season, yellowfleshnectarine with good flavor and keeping quality. The anthers from flowers of male parent were collect⁃ed in bell stage and dried on clean paper in room. The corollas of female parent were removed in balloonstage in spring of 1999. Then, artificial pollination was followed and all the branches were bagged. Twoweeks later, bags were removed. All the trees were managed as normal. In middle July, near maturing, allfruits from artificial pollination were harvested and cleaned in room. After that, the seeds were extractedunder clean bench and stratified in temperature of 2-4 °C on 2 layer of moist filter paper in petri dishes. InDecember, when germinated, the seeds were potted in sterile nutrient media. The hybrid seedlings werecultured in greenhouse till transplanted to selective nursery in the next spring. In middle April of 2000, allthe seedlings were planted with density of 1.0 m×4.0 m. Based on evaluation of main economic charactersof fruits over 2 years, the seedling numbered‘99-47-17’was picked out for its’big round fruit, bright col⁃or, good eating quality, and stable high yield. It was named‘CN 13’in 2014 and licensed in 2016. The ma⁃tured fruit is round and most of the white background covered by shining red. The fruit flesh is white, melt⁃ing, juicy, which tasted sweet. Anthocyanin below skin is middle. The contents of soluble solid, total sugarand total acid in flesh juicy are 13.70%, 10.92% and 0.22%, respectively. The eating quality is very good.The stone is oval, brown and cling to the flesh. The flower is showy and the anther is dark red with muchpollen. It is fertile and very fruitful. In Zhengzhou, middle China, the first flower of‘CN 13’comes intobloom mostly appears in late March and the flowering period can last 5-7 days. The fruit matures in lateJune, about 90 days after blooming. The tree is middle vigorous and semi-opening in canopy. The sprout⁃ing and branching ability are moderate. The new branches are green and dark-red on sunny side. The aver⁃age internode length is about 1.97 cm. The leaf is green and lanceolate in shape with 2-4 reniform glandsalong the petiole. The flower is pink, showy with 5 petals. The tree of‘CN 13’is middle or strong vigorous.The flower buds normally appear from the 1st-3rd internode, even in the first year after planted.‘CN 13’has strong early fruit ability. The yield of 3-years-old tree in middle density could reach over 22.5 tons perhm2. The middle length flower branches are suggested to leave for fruit.‘CN 13’is fertile, so it is not nec⁃essary to bring in pollen donation. Previous testing is distributed mainly in the north China, more testsneed to be done in south China. According to the soil fertile and local rainfall, select a suitable plantingdensity. The V-shaping or quad-V shaping are recommended for the north and the south separately. Forpoor soil, base fertilizer is necessary before planted. In the beginning two years of planted, the shape prun⁃ing is the first priority so as to build a strong and manageable tree architecture. In full fruit period, stabilizethe growth vigor in middle level through fertilizer and yield control. For the canopy, good light penetrationis very important for the flower bud formation and fruit quality, so summer pruning must be done routinelyto keep it free from water branch and let the lower and inner shoots get enough sun shine.