Excellent foreign varieties of walnut

   1, Chandler

Source and distribution of   : originating from the United States, it is the hybrid offspring of Pietro XUC56-224. It is a major early fruiting walnut variety in the United States, which was introduced into China in 1984.

The economic characters of    fruit: the nut is large, the average diameter is 4.4cm, and the average weight of single fruit is 12.86g. The nut is heart-shaped, the shell is smooth and the suture is tight. It is easy to take whole kernel, and the shell is 1.5 mm thick. The kernel rate is 49%, the nucleolus is full, full, the color is creamy yellow, the flavor is fragrant, and the quality of nucleolus is excellent.

   growth and fruiting habits: the tree is moderate in potential, upright in posture, stout in branchlets and medium in internodes. Sprouting late, male first type. Mid-early maturing varieties. The percentage of lateral mixed buds was 80% and 90%. It is suitable to be planted in the areas where the annual average temperature is more than 11 ℃ and the growing period is more than 220d. The grafted tree began to bear fruit in 2 years and formed a male inflorescence 4-5 years later with medium yield.

The variety    has strong adaptability and high temperature tolerance. Sprouting late, resistant to frost and less harmful to black spot. It is suitable to be planted on deep soil with irrigation conditions.

   2, fragrance

Source and distribution of   : selected by Naoki Shimizu from the walnut population in Nagano, Japan, it belongs to the fruit type variety. Hebei Agricultural University was introduced into China and popularized.

   fruit economic characters: the nut is large, the average nut weight is 14.3g; the nut is oval, the fruit shape is large and beautiful, and the suture is tight. The kernel rate is 52%-53%, the kernel color is light yellow, the flavor is sweet, there is no astringency, and the quality of nucleolus is good.

   growth and fruiting habits: the tree is of medium size, the tree posture is half-open, the young tree grows vigorously, and the tree is stable after fruiting. Male first type, mature variety. Generally, only the terminal bud can bear fruit, the fruiting branch is more than 60%, the continuous fruiting ability is strong, the fruit setting rate is more than 85%, the branch rate is 1: 2.3, and the double fruit rate is high. It is highly productive. 3 years after grafting, 5 years of high yield, 278 kg of nuts per 667 square meters. It sprouts and spreads leaves in early April in Baoding, Hebei Province, male flowers in the middle of April, and female flowers in late April. Mature in mid-September. The leaves fell from late October to early November.

   this variety has strong resistance. Anti-freeze, blossom, avoid frost. It has strong resistance to anthracnose and black spot. It is not strict with the soil. It is suitable for large-scale development in North China, Northwest, South-Northeast and Southwest.

   3, Hartley

Source and distribution of   : originated in the United States in 1915, Mr. and Mrs. John Hartley found in their private walnut orchard in the NaPa Valley. It is one of the most widely cultivated varieties in California. It belongs to the variety type of walnut.

The economic character of    fruit: the nut is big, the average weight of single fruit is 13.56g. The nut is broad and flat at base, pointed at the top, heart-shaped. The sutures are tight. The kernel rate is about 45%. 90% are light-colored nucleoli. Hartley is the main variety sold with shell after washing.

   growth and fruiting habits: the tree body is medium to large, the tree posture is half-open, and it grows vigorously on fertile soil. The seed setting rate of lateral buds is about 10%. The initial fruiting age is relatively old, but the yield is very high in the full fruit stage. It belongs to the male type and matures in the middle of September.

   shows high yield in California with light nucleoli and is not vulnerable to apple bark moth and black spot. It is susceptible to deep ulcer of bark, and deep selection is the limiting factor for the cultivation of Hartley when the water content is irregular or the soil is barren. Only when planted in deep, fertile, well-drained soil and reasonably irrigated can it be fruitful. It is suitable for sparse planting with large crown.