A new early-maturing chestnut cultivar Bailuxiang

Abstract：Bailuxiang, a new early-maturing chestnut cultivar, was selected from the wild mature seedling chestnut trees in Yanshan Mountain of Xinglong county, Hebei province by Changli Institute of Pomology, Hebei Academy of Agricultural and Forestry Sciences. The mother tree is 70 years old, growing on the hillside. In 2001, the chestnut research group found the mother tree during the field investigation on the superior chestnut in Sandaohe township. The old chestnut seedling tree has the characteristics of early maturity, high yield, high quality and better tolerance of barren soil. After regional adaptability testing at three sites of Hebei province (including Xinglong, Qianxi and Kuancheng) over sixteen years from 2004 to 2020, it was finally selected in 2021. This cultivar is tall, the tree posture is halfspreading, and the tree has strong growth vigor. The biennial bearing branches are grayish brown in color. The size and density of lenticel are intermediate. Leaf color is yellow green. Leaves are ellipse with serrate, spreading, and gradually acute apex. The average length of catkin is 17.3 cm and the numbers of catkin on each biennial bearing branch is 7.8. The shape of bur is ellipse and bur is cruciformcracked. The spine bundle on the bur is hard, the density is intermediate, and the average length of spine bundle is 1.4 cm. The nut color is purple-brown and bright, and the side nut shape is ellipse. The stripes on nut is not obvious, size of hilum is intermediate, and the regularity of nuts is high. The flesh of nut is faint yellow in color, fine-textured and smooth. The nuts are perfect for stirfry purpose. Cooked nut taste is fragrant and glutinous. And the nut average weight is 10.5 g, each bur contains an average of 2.4nuts, with a seed yield of 38.1%. The water content is 49.5%, the total soluble sugar, starch and protein contents are 23.3%, 51.9% and 4.23%, respectively, and vitamin C content is 27.3 mg·100 g^-1 . Nut quality is excellent. It ripens in early September in Hebei area. Annual branches are strong, with an average length of 47.84 cm and a thickness of 0.76 cm. The average bearing shoot numbers on each biennial bearing branch is 3.65, and each biennial bearing branch has an average of 2.16 burs. The cltivar has good adaptability, and is resistant to barren soil, cold climate, drought, red mite and peach borer, and highly resistant to chestnut blight. The nut has very long storage-life. The new cultivar is appropriate to be planted in mountains, hills and beach sand of the chestnut cultivation area of Hebei province and similar areas. It is early fruiting and produces high yield. This cultivar can bear fruits next year after grafting. Trees grafted after four years has a high yield potential of 3 915.0 kg·hm^-2 . Orchards should be chosen on gneiss mountain or beach sandy lands. The spacing in the rows and spacing between rows are 4 m×4 m. The appropriate pollinizers are Yanxing and Yanming. The cultivar is suitable for training the natural open center system or two-layer small canopy sparse system. The new branches of young trees grow vigorously, and the effect of branch pulling and bud carving is excellent, which can achieve early bearing and high yield. The mature trees can adopt rotational and renewal pruning technology.