Growth region
Chestnut was born and raised in China, with a long cultivation history and rich variety resources and geographical distribution.
Huge. According to incomplete statistics, 1996 national chestnut
Chestnut trees cover an area of1110000 hm 2, with an annual output of 250 million kg. It starts from Hainan Island (18 30' n) in the south and reaches Fengcheng, Liaoning (40 31'n) and Ji 'an, Jilin (4120' n) in the north, all of which are distributed in 25 provinces (cities and autonomous regions) in China. The key producing areas are Yanshan Mountain, Yimeng Mountain, Qinling Mountain, Dabie Mountain and Yunnan-Guizhou Plateau, in which the output of Shandong, Hubei, Henan and Hebei provinces accounts for about 60% of the national output. The low altitude distribution areas such as Changli in Hebei, Tancheng in Shandong and Xinyi in Jiangsu are below 50m. High altitude areas, such as Weixi, Yunnan, reach 2800m, generally distributed between 300-500 m.
chestnut
Chestnuts are called wooden swallows in ancient times. From the Neolithic site in Anbanpo, Xi 'an, the physical remains of chestnuts more than 6000 years ago were discovered.
Feeding history of chestnut trees. Qian 'an, Hebei Province is one of the main producing areas of chestnut.
In addition, chestnuts are widely distributed in China, and through natural hybridization, rich variation types have been formed.
Chestnut is a sweet fruit. According to records, chestnut was widely planted in China before BC and was eaten by people. The producing areas of Li Gan in Tianjin are concentrated in Xiaogang, Xiaoying and other towns in Jixian County. In fact, a large number of chestnut trees grow in the mountainous areas of Beijing, Tangshan and Chengde, and the chestnuts produced in these areas are of good quality. Because chestnuts produced in these areas used to be exported from Tianjin Port, they were named Tianjin Li Gan (known as "Tianjin Chestnuts" in Japan), and were mainly exported to Japan, Australia, the Philippines, Thailand, Singapore, Hong Kong and Macao.
Growth characteristics
Chestnut is a relatively tall tree and fruit tree, and its growth and fruiting have two main characteristics: first, it is strong in light; The second is the result of strong support.
chestnut
Chestnut generally produces fruiting branches from several buds at the top of fruiting branches. Strong fruiting branches not only form yield, but also are the main branches to expand crown and cultivate backbone branches. Shaping and pruning should focus on promoting growth. The top advantage of chestnut makes the growth potential and growth of branches in different parts of the crown have obvious differences. The growth potential of the top upright branches is the strongest, and the strength of the lower branches is weakened in turn. Sagging branches often die of natural causes. The growth of fruiting branches, the number of fruiting branches and the size of chestnut in different parts of the crown are also obviously different. The purpose of shaping and pruning is to balance the growth of various parts and branches, so as to balance the growth and results. Chestnut is dioecious, with strong branches and strong fruits. Flowers and fruits need high light conditions, and various pruning measures should be taken to improve the ventilation and light transmission conditions of each plant and the whole chestnut garden. There are many weak male flowers in the inner room, which should be thinned out. Therefore, one-sided emphasis on the firmness of the inner bore can not achieve obvious benefits.
classify
There are more than 300 varieties of chestnut, the main cultivated varieties. According to its distribution area, it can be basically divided into two groups, namely northern species.
Lifang variety group (local variety group in North China) and southern variety group (local variety group in Yangtze River basin). In addition, there are Dandong chestnut variety group (belonging to Japanese chestnut line) and some dwarf wild chestnuts. The main cultivated varieties are introduced as follows.
chestnut
Huafeng Shandong Fruit Research Institute is a new variety selected from the hybrid offspring of Yeza 12 (Yeli× Chestnut )× Chestnut. The crown of the tree is an open circle. The involucre is oval, weighing about 40g, with an average of 2.9 nuts, each weighing about 8g, and the seed setting rate is 56%. Mature in mid-September. Nuts are neat and beautiful in size, delicate in flesh and sweet, containing 46.92% water, 42.29% starch, 3.33% fat and 8.5% protein. Suitable for frying and storage. Young trees grow vigorously and female flowers are easy to form. 1-2-year-old seedlings can be grafted in the same year, and the results in the following year are 2674.5 kg per hectare in 2-4 years, 6405 kg in 7 years and 4650 kg in 3-7 years.
Huaguang Shandong Fruit Research Institute was bred by crossing 12× chestnut. The crown of this tree is round. The involucre is oval, weighing 43g, containing nearly 3 nuts on average, with an average single seed weight of 8.2g and a seed setting rate of 55%. Mature in mid-September. The size of nuts is neat and bright, the flesh is delicate and sweet, and the water content is 45.73%.
Cultivation management
Whether chestnut trees can strengthen autumn and winter management in time after fruit picking has a great influence on the yield in the coming year.
Fertilize reasonably and give enough "grain". Generally, every 100 kg of chestnut needs to consume 4.5-5 kg of pure nitrogen, 4.5-5 kg of potassium and 0/.5-2 kg of phosphorus respectively.
Li Jin After the fruit was picked, the "vigor" of the tree was seriously damaged. Therefore, fertilizer should be supplemented in time to quickly restore the vitality of the tree, increase nutrient accumulation and improve the cold resistance of chestnut trees in winter. Fertilizers should be mainly organic fertilizers. Generally, for trees with an age of 8- 10, 50-60 kg manure, 0.5 kg urea, phosphate fertilizer 1 kg and 10 trees with an age above, the amount of fertilizer applied should be increased or decreased according to the fruit yield.
chestnut
Irrigation to fight drought and give enough "drinking water". Chestnut roots are widely distributed horizontally, but their vertical distribution ability is weak. After the fruit is harvested, the tree loses a lot of water, and the drought is more serious in autumn and winter, which is easy to make chestnut trees suffer from drought. Therefore, conditional chestnut orchards should be watered once in time after fruit picking to supplement the water in the trees, and then irrigated in time if there is drought.
Cultivate the soil and give it enough "wear". Cultivating soil on the tree base can ensure the growth of tree roots and enhance their cold resistance. 165438+1in the middle and late October, each tree should be covered with a layer of fine soil with 2-4 loads of decomposed farmyard manure as the center under the crown. Dig it out when the temperature rises in the next spring, which is convenient for ventilation, takes root and reduces weeds.
Pest control and "health care". In autumn, the main pests that harm chestnut trees should be treated with pesticides in time. After fruit picking, attention should be paid to cleaning up the garden in time, cutting off dead branches and branches with serious pests and diseases, removing branches and leaves with pests and diseases falling off the ground, and burning or burying them centrally.
chestnut
Reasonable pruning, surgery "beauty". In autumn, chestnut sap is still flowing, and the temperature is relatively high. At this time, pruning can not only make the wound heal quickly, but also avoid the sprouting of clustered branches near the wound. For chestnut trees at the initial stage of fruiting, only dense branches and long branches with inappropriate positions are pruned; For the trees in full fruit period, thinning is the main method, combining expansion and contraction, maintaining tree shape and coordinating the relationship between vegetative growth and reproductive growth; It is advisable to recover the branches of aging trees in a planned way to renew and rejuvenate them and prolong their fruiting life.
Technical methods of pest control
Chestnut weevil and peach fruit borer have become the main pests of chestnut in Tongbai Mountain area in recent years. Two kinds of pests overwinter as larvae every two years 1 generation, and 3 ~ 4 generations a year, which are harmful from July to September every year. In larval stage, chestnut fruit was fumigated with 56% aluminum phosphide and 98% methyl bromide for 48 hours, and the mortality rate was 90% ~ 100%. When spraying 20% acetamiprid wettable powder 2500 ~ 3000 times during the egg stage of chestnut weevil, the moth-eaten rate decreased by 95%.