A new red-flowered nectarine cultivar Zhongnong Zhenzhu 5

Zhongnong Zhenzhu 5 is a medium-ripening and red-flowered nectarine cultivar developed from the cross between Zhongnong Zhenzhu and Zhongnong Honghua Zhenzhu 1 in 2013 at the Juxian Institute of Peach Breeding Nursery. Initially, 156 natural seedlings were cultivated in a greenhouse and subsequently transplanted to a breeding nursery in May 2014. The seedlings began fruiting in 2016, and their botanical and economic traits were documented over a two-year period (2016—2017). In 2017, the selection code 2013-664, recognized for its exceptional overall characteristics and red flowers, was identified as a promising candidate for further evaluation. It underwent regional adaptability testing in Rizhao and Linyi City from 2018 to 2022. Officially designated as Zhongnong Zhenzhu 5, it received licensing from the Ministry of Agriculture and Rural Affairs in 2022 under the code GPD peach (2022) 210019. The tree is characterized by moderate vigor and a semi- open growth habit, with a strong branching capability. The sunny side of the young branches displays a reddish-brown color, while the reverse side is green. The average internode length of the young branches is 2.5 cm, featuring doubleflowered buds. The leaves are elliptical-lanceolate, with a nearly right-angled base and a medium tip angle, measuring 11.7 cm in length and 3.2 cm in width, accompanied by a petiole length of 0.8 cm. The flowers resemble roses, showcasing red petals and fuchsia anthers, producing abundant fertile pollen and demonstrating a high self-pollination setting rate. The fruit is oblate, with over 80% of its surface exhibiting a deep red hue. The average fruit weight is 95 g, with a maximum weight of 113 g. The flesh is white, firm, and moderately juicy, with red pigmentation surrounding the stone, and offers a sweet flavor. Key fruit quality metrics include an average soluble solids content (SSC) of 13.7%, total acidity of 0.16%, flesh firmness of 14.9 kg · cm- 2 , and a harvesting duration exceeding 7 days. The fruit demonstrates good storage and transportation capabilities, with a shelf life of 8-10 days. In the Rizhao area, flowering occurs in late March, and fruit ripening takes place in early August, with a development period of approximately 120 days, similar to its parent, Zhongnong Zhenzhu. The defoliation period occursin early November, resulting in a total growth period of approximately 260 days. This cultivar exhibits high resistance to aphids and stable yields, making it suitable for cultivation in peach-producing regions of Shandong province and its surroundings. The tree begins to bear fruit in the spring following planting, with yields reaching up to 2500 kg per 666.7 m² by the fourth year. Pruning is recommended during both dormant and growing seasons to manage tree shape and vigor. Ridge cultivation with a‘Y’ shaped tree system and spacing of (1.5-2.0) m × (3-4) m is advised. While the cultivar can achieve high yields through self-pollination, fruit thinning is essential to enhance fruit quality and maintain appropriate tree vigor, with a recommendation to retain one fruit every 8- 10 cm on the same side along a branch. The yield should be managed at 1500 kg per 666.7 m2 .