What are the main improved walnut varieties in China?

  1. Liaoning No. 1

  Source and distribution: Bred by the Liaoning Institute of Economic Forestry through artificial hybridization. Belongs to the early-bearing walnut variety type.

  Economic traits of the fruit: The nut is round, weighing 9.4 grams. The shell surface is relatively smooth, light in color, and the shell thickness is about 0.9 mm. The whole kernel can be extracted. The kernel weighs 5.6 grams, and the kernel yield is 59.6%. More than 90% of lateral buds form mixed buds.

  Growth and fruiting habits: This variety has strong tree vigor, an upright or semi-spreading tree form, and strong branching ability. It is extremely high-yielding. Each female inflorescence bears 2-3 female flowers, and the fruit-setting rate is over 60%. It belongs to the protandrous type. The nuts mature in late September. The average nut yield per tree at 5 years old is 1.5 kg, with a maximum of 5.1 kg. Top-grafted trees at 4 years old average 2.1 kg of nuts per tree. This variety has strong adaptability and cold resistance, and is suitable for cultivation in northern walnut-growing regions.

  2. Xiangling

  Source and distribution: Bred by the Shandong Institute of Pomology in 1978 through hybridization of the early-bearing superior line Shangsong No. 5 x Aksu No. 9. It passed appraisal by the Ministry of Forestry in 1989. It is currently being introduced and cultivated in various provinces of North China and Northwest China. Belongs to the early-bearing walnut variety type.

  Economic traits of the fruit: The nut is oval, medium-sized, with an average single nut weight of 10.6 grams and a maximum of 13.2 grams. The average of the three diameters is 3.4 cm. The shell surface is smooth and attractive, and the shell thickness is 0.99 mm. The suture line is relatively loose, and the whole kernel can be extracted. The kernel yield is 57.6%, the kernel color is light, the flavor is fragrant, and the quality is superior.

  Growth and fruiting habits: The plant grows moderately, with a spreading tree form, a branching angle of about 70 degrees, and a semicircular crown. The leaves are relatively small and green. It belongs to the protandrous type and is a mid-season variety. This variety has strong high-yield potential, but the fruit becomes smaller when fertilizer and water are insufficient, and the tree vigor tends to weaken when it bears too much fruit. Pay attention to applying more organic fertilizer and maintaining an appropriate load to extend the fruiting life. Its cold resistance, drought resistance, and disease resistance are relatively poor, and it has strict requirements for fertilizer and water conditions. Drought and extensive management can shorten its fruiting life.

  3. Daixiang

  Source and distribution: Daixiang is a new walnut variety bred by artificial hybridization of Liaohe No. 1 x Xiangling. It was designated as a superior line in 1997 and passed appraisal and was named by the Shandong Provincial Forest Tree Improved Variety Examination and Approval Committee in 2003.

  Economic traits of the fruit: The nut is large, oblong, with a longitudinal diameter of 4.0 cm and a transverse diameter of 3.6 cm. The average single nut weight is 13.9 grams. The shell is relatively smooth, and the suture line is tight and slightly protruding, not easy to crack. The shell thickness is 1.0 mm, and the whole kernel is easy to extract. The kernel weight is 8.1 grams, and the kernel yield is 58.27%. The kernel is plump, light in color, fragrant in taste, and not astringent. The fat content is 66.2%, and the protein content is 20.7%. The quality is excellent.

  Growth and fruiting habits: The tree is robust, and the crown is dense and compact. The branches are thick, and the internodes are short (average 2.42 cm). The branching ability is strong (1:4.3). The mixed buds are large and plump. Each fruiting branch bears 2-4 female flowers, and the proportion of lateral flower buds is over 95%. It often bears double and triple fruits, and the fruit-setting rate is 70%. The fruiting branches produced from fruiting mother branches are short and numerous, and the fruiting branch rate is 91.2%. It has a strong ability to bear fruit continuously, with high and stable yields. Male flowers are relatively few. It is protandrous, and the fruit matures in early September. Its female flowering period is close to the male flowering period of protogynous varieties such as Lufeng and Zhonglin No. 5, so they can pollinate each other. It belongs to the early-bearing type. It flowers in the first year after planting, bears fruit in the second year, and enters the high-yield period in the fourth year. This variety is dwarfed, so the tree shape should adopt a small-crown sparse-layer form. It is suitable for dense planting orchards and has strong stress resistance. When cultivated in mountainous areas with poor soil, fertilizer, and water conditions, growth is slow, which affects early yield. It is most suitable for development in northern walnut-growing regions with a soil layer more than 1.0 m thick and a pH of 6.3-8.2.

  4. Wen 185

  Source and distribution: Selected by the Xinjiang Academy of Forestry Sciences from the Wensu thin-shell variety group in the Aksu region. It passed appraisal by the Ministry of Forestry in 1989. Belongs to the early-bearing walnut variety type.

  Economic traits of the fruit: The nut is medium-sized, with an average single nut weight of 11.2 grams and a maximum of 14.2 grams. The average of the three diameters is 3.4 cm. The shell surface is smooth and attractive, and the shell thickness is 1.09 mm. There are occasionally exposed-kernel nuts. The suture line is relatively loose, and the whole kernel can be extracted. The kernel yield is 58.8%, the kernel color is light, the flavor is fragrant, and the quality is superior.

  Growth and fruiting habits: The plant grows moderately, and the tree form is relatively spreading. The branching angle is about 65 degrees, and the crown is semicircular. The leaves are relatively large and dark green. It belongs to the protogynous type and is an early-maturing variety. This variety has a strong ability to bear fruit continuously, is especially high-yielding, and has excellent quality. It has relatively strong adaptability and is relatively resistant to cold, drought, and disease. The crown is compact, making it suitable for dwarfed dense planting. Pay attention to thinning flowers and fruits to ensure continuous high yields and no decline in nut quality. It requires good fertilizer and water conditions and prefers to grow in loose soil. If cultivation conditions are poor, the fruit will become smaller and the quality will decline.