C. cathayensis is about 30 meters high, with smooth skin, odd pinnate compound leaves and 5-7 leaflets. Nuts are ovoid or broadly oval, with a large top and a thick shell. There are about 292 nuts in 1 kg, and the seeds are large and often 4-cracked. After astringency removal, they are delicious and can be used for frying or processing candy cakes, and also for oil extraction.
2. Excellent varieties:
Most pecans of round fruit species belong to this type. The nut tip is oval, the top of the fruit is sharp, the left and right halves are skewed and asymmetrical in size, the shell is thick, the inner wall has two big partitions and six small partitions, the shell is easy to peel, and the kernel is often complete.
The nut of flat fruit is oblate, with a slightly protruding top, a round base and a thick shell. The inner wall is divided into three big partitions and then divided into nine small partitions. Because there are many grooves in the shell, it is difficult to peel the shell, and the peeled kernels are mostly incomplete.
Thin-shell species are mainly produced in Lin 'an area, with a shell thickness of 0.08 ~ 0.10cm, a kernel yield of 46% and an oil yield of 72%, with good quality. At present, the number of plants is small, so it should be vigorously propagated and popularized.
3. C.illinoensiskoch
Carya cathayensis and Carya cathayensis belong to different species. Also known as Carya illinoensis, Carya illinoensis. Native to Mississippi River valley and southern Gulf of Mexico. According to Professor Wu Gengmin's investigation, around 1900, American female missionaries were introduced to Jiangyin, Jiangsu, China. At present, the introduction and distribution in China are wide, with many cultivated in Nanjing, Jiangyin, Huai 'an, Hangzhou, Lin 'an, Wenzhou and Xiamen, but no commodity base has been established so far.
Carya cathayensis has a delicious nut kernel and the best quality among walnut trees. It can be eaten raw, fried or made into candy, and can also be used to extract oil. Wood is strong, tough and dense in texture, which can be used for national defense or making exquisite furniture. The majestic tree is suitable for street trees or trees beside banks and reservoirs, which is easy to propagate. Besides grafting, it can be planted in root cutting and is suitable for planting in warm and humid environment in the south.
Because of the tall tree, it is inconvenient to manage, and the late entry into the high-yield period, many varieties of Carya cathayensis can not bloom at the same time, so artificial pollination is needed to improve the fruit setting rate.
Carya cathayensis has not been produced as a processed commodity in China. After being graded, cleaned and shelled by factories in the United States, nuts are mostly used as raw materials for making candy, bread, ice cream or snacks.
5. Harvest, processing and market: Usually, the color of the external involucre of the fruit changes from green or blue-green to yellow-brown, that is, it is mature. If the empty fruit is caused by poor fertilization and other reasons, it is not easy to separate, so that the good and bad fruits can be distinguished. Nuts after debranching should be steamed and dried immediately, otherwise they will go bad easily. Nuts that cannot be treated in time should be thinly spread in a ventilated place indoors and dried in the shade.
At present, the main processed products in China are salt and pepper hickory, hickory candy, etc. Because of limited output, the demand exceeds supply and the market prospect is good.