Efficient cultivation techniques of Carya cathayensis

American pecan, also known as American thin-shell pecan, thin-shell pecan or long pecan, is a deciduous tree of the Carya family. American pecan fruit is actually called green root fruit or longevity fruit in the market, which has been sold well in Jiangsu, Zhejiang and Shanghai in recent years, and has a tendency to expand to the north. Carya cathayensis can not only produce delicious and nutritious nuts, but also produce high-quality wood, but also can be used as a street tree for greening and beautification.

Carya cathayensis is native to North America. As early as the beginning of the 20th century, China introduced a small number of tree species from the United States. At present, in the vast areas from the Great Wall in the north to Yunnan and Jiangxi in the south, there are reports of successful introduction and cultivation of Carya cathayensis, and many areas have received good economic and ecological benefits.

pragmatic value

1. Dried fruit and shell

American pecan is one of the world-famous high-quality dried fruits, which is deeply loved by consumers in the United States and European countries. It has large nuts, thin shell, high kernel yield (50%-70%), easy kernel extraction and high yield (1500-2250 kg / ha, 100-150 kg / mu). The nuts are delicious, non-astringent, nutritious (72% oil, 11% protein, 13% carbohydrates), high in amino acids and rich in vitamins B1 and B2. Nuclear oil contains 73% monounsaturated fatty acids and a calorific value of 32 kcal / kg, which can reduce the incidence of coronary heart disease after consumption. It is an ideal health product and food additive. The price of nuts is $60.7 / kg in the United States and about 80 yuan / kg in China. Its shell is a kind of advanced polishing material after crushing, and its price is similar to that of nucleolus.

2. Wood

American pecan is one of the three high-quality hard broad-leaved timber species juxtaposed with American black walnut and black cherry. Its wood has fine structure, high mechanical strength, beautiful texture and color, and has a wide range of uses, especially for making high-grade furniture and plywood veneer, as well as tool handles, pianos, gyms, sporting goods and interior decoration. In the United States, American hickory furniture and handicrafts have always been a symbol of elegance and wealth.

3. Afforestation and beautification

The American pecan tree is tall and upright, beautiful in shape, with a life cycle of 80 years and 100 years, and its fruit and leaves shine against each other. It is an excellent tree species for courtyard beautification and urban greening. Pecans can be found in many farms, manors, parks, schools and churches in the United States. There are 80-year-old American pecan street trees on Taiping North Road in Nanjing, China, which have excellent greening and beautification effect and are deeply loved by the public.

Variety classification and selection

1. Classification

Pecans are divided into eastern, western and northern varieties according to climate and geographical location. The eastern varieties are suitable for high temperature and humid climate with strong disease resistance, the western varieties are suitable for relatively dry climatic conditions, saline-alkali tolerance and weak disease resistance, and the northern varieties are suitable for the climate of short growing season with strong cold and drought resistance and good nut flavor. In China, it is roughly divided into southern varieties and northern varieties. The southern varieties are resistant to high temperature, humidity and cold, so they are suitable for cultivation in the south of the Yangtze River, such as Moneymaker, while the varieties in the north are resistant to cold and drought, which are not only suitable for cultivation in the area between the Yangtze River and the Great Wall, but also suitable for cultivation in the south of the Yangtze River, such as Pawnee.

2. Character

The shapes of American pecan nuts are round, oval, oval and obovoid, and most of them are oval. There are different sizes of fruit, about 60 grains / kg of large fruit type and 140 million grains / kg of small fruit type.

3. Select

In the south, we can choose the southern type or the northern type, mainly considering the disease resistance of the varieties, while in the north, we must choose the northern type varieties, mainly considering the cold resistance, drought resistance and frost-free period.

Cultivation environment

1. Climatic conditions

Carya cathayensis is generally distributed in the area of 2642 degrees north latitude, and the main commercial cultivation area is in the range of 28,36 degrees north latitude. The frost-free period in the natural distribution area is 140,280 days, the frost-free period in the main producing areas is more than 220days, the annual accumulated temperature of ≥ 10 ℃ is 3300 ℃ ~ 5400 ℃, and the minimum accumulated temperature for cold degree is 500℃. The annual precipitation is 1000-1600 mm in the southeast of the distribution area, and 500-800 mm in the western and northern regions.

Carya cathayensis is the most suitable environment with an average annual temperature of 15 ℃ ~ 20 ℃. The northern varieties can tolerate the low temperature of minus 29 ℃, the southern varieties can only tolerate the low temperature of minus 18 ℃, and the extreme high temperature is 46.5 ℃. It is reported that pecans are suitable to be planted in most areas south of the Great Wall and across the east and west of China. In addition, the American pecans planted in the north have better nut flavor and wood than those in the south. At the same time, northern varieties can grow better in the south, with larger fruits and full kernels.

2. Soil conditions

Pecans like sandy loam or loam with deep, loose, humus-rich, moist and well-drained soil, which is not suitable for acidic soil that is too sticky. Carya cathayensis does not have strict requirements on soil pH value, and can grow well in the range of pH 5.8-8.