Hawthorn is a perennial deciduous fruit tree and tree in the Rosaceae family. Also known as mountain red and red fruit. The scientific name is Crataegus pinna-tifida Bge.

Origin and Distribution

Hawthorn is native to China, North Korea and Soviet Siberia. There have been records about hawthorn as far back as 2000 years ago. For example, it is recorded in "Erya" that "Xiu Yinqiu, the tree is like a plum, and its seeds are as big as a finger, red like napkins, edible, this is hawthorn." In the 3rd century Jin Dynasty, "Guangzhi" recorded "Xiu Muyi" It grows, grows many kinds of crops for salary, and fertilizes the fields.” The first record of medicinal use was in the Liang Dynasty's "Shen Nong's Materia Medica", followed by the Tang Dynasty's "Compendium of Materia Medica", the Ming Dynasty's "Compendium of Materia Medica", "Qunfang Pu", "Nongzheng Complete Book", the Qing Dynasty's "Compendium of Materia Medica" and other books. There are records of hawthorn being used as medicine, but there are few records of cultivation techniques. Hawthorn cultivation flourished in the mid-to-late 19th century. At that time, Henan, Shanxi and other places introduced hawthorn from Shandong. Since the mid-1970s, hawthorn has received widespread attention due to its nutritional and medical health care value. Especially since the early 1980s, hawthorn cultivation has Great development. Hawthorn has strong adaptability and good yield. Generally, the output per hectare of cultivation can reach more than 22.5 tons. It is easy to manage and the fruit is durable for storage and transportation. It is suitable for the development of mountains and desert lands.

Hawthorn plants are widely distributed in the northern hemisphere, Asia, Europe and the United States. In China, Crataegus plants are distributed in many provinces (autonomous regions), with the largest number in North China and Northeast China. The main production areas are Liaoyang and Kaiyuan in Liaoning Province, Yidu, Tai'an, Laiwu and Pingyi in Shandong Province, and Xinglong and Kaiyuan in Hebei Province. Qinglong, Zunhua, Funing, Laishui, Jincheng in Shanxi Province, Linxian and Huixian in Henan Province, Fangshan in Beijing, and Jixian in Tianjin. According to statistics in 1986, the national annual hawthorn output was more than 150,000 tons. Hawthorn cultivation is most popular in China.

Characteristics and characteristics

Hawthorn varieties are different, but their morphological characteristics, growth and fruiting habits, phenology, etc. have the same characteristics.

Morphological characteristics

The hawthorn tree is 6 to 7 meters high. The bark is dark gray. The leaves are solitary, broadly ovate or triangular-ovate, 5 to 11 cm long and 4 to 7 cm wide, with apex acuminate and pinnately split with 5 to 9 lobes. The leaf margins are sharply serrated, the surface of the leaf is dark green, and the underside of the leaf is dark green. Light green; petioles 2 to 6 cm long. The flowers are bisexual, with white petals. There are 12 to 25, up to 44 flowers forming a corymb, shaped like a flower ball. The fruit is nearly spherical, oblate or oblong; the fruit surface is purple-red with many fruit spots; the flesh is pink, purple-red, green and other colors.

Growth and fruiting habits

Hawthorn seedlings begin to bear fruit 2 to 4 years after planting, and enter the fruiting period in about 10 years. The economic cultivation life span can reach more than 100 years, and the yield of a single plant is the same as that of a tree. The size varies. Generally, the yield of a plant is 30 to 50 kilograms, and there are also large hawthorn trees with a yield of more than 500 kilograms.

The buds of hawthorn are divided into flower buds, leaf buds and hidden buds. The flower buds are mixed buds, nipple-shaped, fat and full, with a rounded apex. They are borne between the top of the current-year branch, that is, the fruit-bearing mother branch, or 1 to 4 leaf axils below the top. In the following spring, the fruit-bearing branches with flowers and fruits will germinate. ; The leaf buds are small and pointed, and most of them are located between the middle and upper leaf axils of the developing branches of the current year. They will germinate and produce developing branches with only leaves in the following spring. Cryptic buds are mostly located between the middle and lower leaf axils of the current year's developing branches. They will not germinate in the next year and will be latent. Its lifespan can last for decades. Once stimulated, it will break through the bark and send out leggy branches.

Hawthorn has strong branching ability, dense branches, and open branches. After entering the fruiting period, all developing branches with moderate development and substantial growth can form fruiting mother branches. When nutrients are sufficient, after the fruiting branches bear fruit, the lower 1 to 2 lateral buds can form mixed buds that year and become the fruiting mother branches of the next year. The fruiting branches will continue to bloom and bear fruit in the next year. Generally, they can form a forked shape for more than 2 to 4 years. Branching can easily lead to stagnation in the crown, so it should be properly renewed and rejuvenated. Leggy branches can produce several developing branches in the second year. When conditions are suitable, the top buds of some developing branches differentiate into flower buds, and fruiting branches will bloom and bear fruit in the third year. Generally, hawthorn trees have mostly fruiting mother branches that are about 7 cm long. Usually, one fruiting mother branch bears 1 to 2 fruiting branches. Individually strong fruiting mother branches can also bear 4 to 5 fruiting branches, or even more. It has many fruit-bearing branches and is easy to bear fruit year after year. The differentiation period of flower buds is late, starting from August to September, and there is little conflict with fruit development. The differentiation of flower buds stops at the petal stage, and the differentiation of male and female flower primordia is completed before germination the following year.

Phenological period

The growth period of hawthorn is about 180 to 200 days, and it takes 140 to 160 days from flowering to fruit maturity. In spring, the root system begins to move when the local temperature is 6.5°C, and begins to germinate at 8°C. The growth period of the fruiting branches is short, generally only growing for 10 to 20 days before flowering and stopping growth. The flowering period is about 9 to 21 days, and the fruit matures late, usually in September. Harvest in October or even before frost. In Liaoyang, Liaoning Province, buds sprouted on May 7, bloomed on May 26, matured on October 12, and dropped leaves on October 26.

Requirements for environmental conditions

Hawthorn plants have strong adaptability and are not very strict with environmental conditions. The annual average temperature is 2~22.6℃, and the absolute minimum temperature is -1~- 41℃, ≥10℃ accumulated temperature 2000~5000℃, frost-free period of more than 100 days, and annual average precipitation of 170~1546 mm. There are different types of soils, whether it is mountains, hills, plains, deserts, or acidic to weakly alkaline soils. , varieties of hawthorn are distributed or cultivated and perform well.

Hawthorn loves light. In an environment with good lighting conditions, the fruit setting rate can be significantly improved. The fruits are well colored and have high sugar content. Although hawthorn has certain drought resistance, ensuring adequate moisture during the growth period will help fruit enlargement and increase fruit setting rate. Irrigation is necessary when rainfall is low. Poor drainage can easily lead to waterlogging and death of trees. The roots of hawthorn are distributed 40 to 60 centimeters underground, but they can still extend downward when the soil is deep, so hawthorn should be planted in areas with deep soil.

Main varieties

As a fruit tree, C.pinnatifida var.major N.E.Br., a variant of hawthorn, is widely cultivated. It has the most cultivated varieties; the main cultivated varieties are: ① Northern Henan is red. Produced in Huixian, Linxian and other places in Henan. The fruit is nearly spherical and large in size, about 100 per kilogram. The peel is bright red to purple, the flesh is soft, mostly pink, and tastes sour and slightly sweet. The fruits mature in early October, resulting in high and stable yields and are mainly used for processing. ②Autumn Venus (Big Venus). Produced in Laiwu and Fei County, Pingyi, Shandong, Anshan, Liaoyang, Liaoning and other places. The fruit is nearly spherical, with an average fruit weight of 5 to 10 grams. The peel is bright red, the flesh is delicate and strong, moderately sweet and sour, and is used for fresh eating or processing. It matures in late September and is an excellent variety in Shandong and central and northern Liaoning provinces. ③Exposure. Produced in Yidu, Linqu and other places in Shandong. The fruit is oblate and round, with an average fruit weight of 9 to 9.5 grams. The peel is dark red, the flesh is pink, the flesh is dense, the taste is sour and slightly sweet, and it is suitable for drying. It matures in early and mid-October, has high and stable yields, is drought- and alkali-resistant, and has good quality. ④ Yan flesh is red. Produced in Longhua, Xinglong, Chicheng and other places in Hebei Province, it is the main variety grown in the mountainous areas of western and northern Hebei Province. The fruit is obovate in shape and weighs 7.6 grams per fruit. The peel is dark red and shiny, the flesh is thick, pink, dense, moderately sweet and sour, and of good quality, suitable for fresh eating and processing. It matures in early October and is resistant to drought and cold. ⑤Red-flesh cotton. Produced in Fushan, Laixi and other places in Shandong. The fruit is oblate, with an average fruit weight of 12 grams. The peel is dark red, the flesh is thick, pink, dense and sour. It matures in mid-to-late October, is storage-resistant and suitable for processing. ⑥Soft seeds. Produced in Xifeng, Kuandian, Liaoyang and other places in Liaoning. The local name is Seedless Shanlihong. The fruit is nearly spherical, weighing 1.5-2 grams per fruit, with bright red skin, pink flesh, thin and soft flesh. The seeds are small, soft and edible. Ripe in mid-September, eaten fresh or processed. ⑦Little Venus. It is produced in Longhua, Hebei, Fangshan, Beijing and other places, and is also cultivated in Liaoning. The fruit is bright red. A single fruit weighs 9 grams, with pink flesh, moderate sweetness and sourness, and good quality. It matures in early October and is suitable for fresh eating or processing. ⑧Hawthorn. Produced in the Changbai Mountains, Greater and Lesser Khingan Mountains in Northeast China and Liaoning Province. The fruit is oblate and spherical, and a single fruit weighs 2.5 to 3 grams. The peel is light red, the flesh is pink and white, the flesh is soft and slightly soft, with moderate sweetness and sourness. It matures early and can be harvested in August, making it suitable for processing. It has strong cold resistance and can withstand low temperatures of -41℃.

Other excellent varieties include: red-meat Liaohong, Xifenghong, Ji’an purple-meat, and Luanhong; sweet and slightly sour varieties include Shandong Tianhongzi; and Hanlu, which contains higher medicinal ingredients. Red, noodle, yellow fruit type sweet hawthorn, etc.

Key points of cultivation techniques

Propagation

Grafting is often used for propagation. Rootstock seedlings are usually cultivated through three methods: returning seedlings to the nursery, root seedlings and sowing seedlings.

① Nursery nursery means taking advantage of the tendency of hawthorn trees to develop root tillers. In the autumn of the first year and the spring of the following year, wild root tillers with a diameter of 0.3 to 0.5 cm are transplanted to the nursery for intensive cultivation. They will be budded in the autumn and released from the nursery the next year; ② Burial Root seedlings take advantage of the hawthorn root system's tendency to produce adventitious buds. Roots with a diameter of 0.3 to 0.6 cm are selected and cut into 15 to 18 cm long root segments. They are cut in the nursery in autumn or spring. After the germination survives, they are grafted in the autumn of the same year. It comes out of the nursery every year; ③ Sowing and raising seedlings is to collect wild hawthorn seeds, sow them in the nursery and grow them into seedlings, and then graft and cultivate them. Due to the hard shell of hawthorn seeds and the physiological dormancy of the embryo, water and air cannot easily penetrate into the seed kernel, so it is difficult to germinate. The seedlings often do not emerge in the year after sowing, but only emerge in the second year. Therefore, it is necessary to extend the seed stratification time so that after two winters and one summer, the seeds are stored in the sand in the autumn of the year they are collected, and sown one year apart in the spring of the third year to ensure neat emergence; dry and wet methods are also used to crack the seed husks by removing the seeds. Put it into 70℃ hot water, stir and soak for 1 to 2 days, then take out the seeds and put them on the stone slab or cement floor to expose in the sun during the day, and still put them in the water at night. Repeat this for 7 to 10 days, and the seed shell will crack. Finally stratified storage. Sow the seeds when they germinate in the following spring, and seedlings can emerge that year. After grafting, they will emerge from the nursery in 2 to 3 years. Bud grafting and branch grafting are commonly used for grafting. The T-shaped bud grafting method is often used for bud grafting, and can be carried out in spring, summer, and autumn. The optimal period is July to August; split grafting is commonly used for branch grafting, and the optimal period is before and after budding in spring.

Planting

It can be planted in both autumn and spring. It can also be planted in the rainy seasons of summer and autumn, especially in arid mountainous areas. The planting density can be 3 meters × 4 meters in row spacing in areas with poor soil, and 4 meters × 5 meters in areas with fertile soil. To facilitate orchard operations, wide and narrow rows can also be planted in strips.

Soil Management

Hawthorn roots are prone to sprouting, which affects the growth of the tree. They must be removed frequently to reduce the consumption of nutrients and water and promote the roots to extend deep into the soil, but the thick roots must not be damaged. . In addition to base fertilizer, top-dressing fertilizers can be applied before flowering and during the rapid fruit expansion period. Before flowering, quick-acting nitrogen fertilizers are mainly used, and during the fruit expansion period, nitrogen, phosphorus, and potassium mixed fertilizers are applied. At the same time, top-dressing fertilizers for older trees should be strengthened in the later period to make up for the large number of fruits. If the nutrients are insufficient later, young trees should be fertilized in the early stage to increase the fruit setting rate. In general, using 30 to 70 ppm of gibberellin during the flowering period can also increase the fruit setting rate. Irrigation can be carried out before germination, flowering and fruit expansion in spring. It is best to choose beans, peanuts, potatoes, melons, etc. as intercrops.

Pruning

The hawthorn tree shape can be a natural open shape or a modified main trunk shape, preferably a sparsely layered main trunk shape with low trunk and short crown. Try to keep the inside of the crown as ventilated and light-transparent as possible. The proportion of fruiting branches should account for about 50%, the average thickness should be about 0.45 cm, more than 5 fruits per inflorescence, and the leaf area index 4-5. Most of the saplings have medium to long fruiting mother branches. After 1 to 2 years of fruiting, they should be retracted and pruned to cultivate the fruiting branch group to prevent the fruiting parts from moving outward. At the same time, attention should be paid to thinning out overly dense and redundant branches; the trees in the fruiting period should focus on Retract and thin out the fruiting branches to maintain a strong tree vigor, so that developing branches and fruiting branches can be formed both inside and outside the crown. Pay attention to retaining the long branches in the vacant parts and cultivate them into groups of fruiting branches. Aged trees should have their main and side branches return. shrink, promote new shoots, and cultivate new crowns.

Harvesting

When the fruit turns red and the fruit spots are obvious, it can be harvested. Use scissors to cut off the fruit handle or pick the fruit by hand to keep the fruit intact. You can also use a bamboo pole to knock or shake the branches to shake off the fruit. Some fruits will be damaged. The ethephon-induced fall method uses 40% ethephon 1,000 times sprayed one week before harvesting and then uses a machine or hand to shake the trunk, which can shake 90% of the fruits. It is best to combine artificial harvesting with ethephon-induced fall. The harvested fruits are piled under the trees for several days to dissipate heat, covered with straw curtains or mats during the day, and then packed in baskets after cooling.

Storage

Hawthorn fruit is easier to store. The key is to maintain appropriate temperature and humidity. The general temperature is 0~5℃. If the temperature is 0℃, the relative humidity should be 85~95%; if the temperature is above 0℃, the relative humidity should be 80~85%. Storage methods include cellaring, vat storage, basket storage and burial. The burial method is to dig a circular pit with a depth of 1 meter and a diameter of 0.7 meters in a shady place. Lay a layer of fine sand 15 to 20 centimeters thick at the bottom of the pit, and then select undamaged fruits and pile them on the sand to a thickness of about 50 centimeters. Then cover it with 15 to 20 centimeters of fine sand, and finally fill it with soil or pile it into a mound. Store it from October to November and can store it until May of the next year. The method is simple, the effect is good, and it does not need to be buried after burial. manage.

Pests and diseases control

The main pests and diseases of hawthorn are: ① Heart-eating insects. There are white heartworms and pear heartworms. Prevention and control include removing the infested fruits and burning them intensively; spraying pesticides such as fenitrothion and trichlorfon during the peak spawning period; Tao Xiao can be controlled by ground application. ② Scarabs. There are apple-haired chafers, small blue-and-white chafers and white-star chafers. Eating flowers and fruits. Use manual trapping or light trapping, or spray pesticide powder on the ground. You can also spray bumethane emulsion, monocrotophos, 1605 and other chemicals. ③Scale insects. There are Salituo brown bulbs and Sophora japonicas that stick to the branches and suck sap. The small larvae also damage the leaves. The control method is to spray diesel emulsion, lime sulfur mixture, fenitrothion, carbaryl and other chemicals. ④ Powdery mildew. Damages leaves, shoots and fruits. Control is to spray 5 degrees lime sulfur mixture before germination, and spray 50% wettable carbendazim 600 times during the growth period.

Economic value

Hawthorn fruit is rich in nutrients, containing carbohydrates, protein, fat, organic acids, calcium, iron, phosphorus and multiple vitamins. It is more nutritious than citrus, apple and other fruits. The content of main nutrients is high, especially the content of vitamin C, which is second only to dates and kiwis. It is 1.7 times that of apples and 2 to 3 times that of citrus. The calcium content reaches 850ppm; it also contains a large amount of red pigment and pectin. And a variety of medicinal ingredients, including vitamin C and flavonoids, which have anti-cancer effects. Hawthorn has been used as medicine for thousands of years. In recent years, it has been discovered that the roots, leaves, flowers, and seeds can be used as medicine and can be made into granules (Mai'antong Tablets) and tablets (Jianxuelipide Tablets, Xinmaitong Tablets). There are many types of hawthorn processing, such as hawthorn juice, hawthorn wine, hawthorn sauce, canned hawthorn, candied haws, hawthorn preserves, hawthorn paper (fruit peel), hawthorn candy, dried hawthorn slices, hawthorn jelly, etc. The products are sweet and sour, and have good color, fragrance and flavor.

Hawthorn germplasm resources

A general name for plants that have certain genetic material and are valuable in hawthorn production and breeding. There are about 1,000 species in the genus Crataegus. Widely distributed in the northern hemisphere. North America has the most species, with about 800 species; Europe and Africa have about 60 species. There are 17 species that have been identified in China (as shown in the table). Although there are many species of Crataegus, only a small number are used as fruit trees in cultivation (var.geholensisSchneid.) Long-haired variant (var.psilosaSchneid.) Hairless variant (var.maiorN.E.Br.) Jiangsu large-fruited variant in southern, Shandong, and Shanxi , Shaanxi, Ningxia, Inner Mongolia, Hebei, Heilongjiang (C.pinnatifidaBge.), Heilongjiang, Jilin, and Liaoning. There are only a few species of hawthorn distributed in China, and the others are mainly for garden viewing.

The large-fruited variety of hawthorn is the main cultivated target for fruit tree production and is mainly distributed in the Liaohe River Basin and Yellow River Basin in China. The remaining species are mostly used as rootstocks, medicinal or ornamental.

Figure 1. The chromosome number of Hawthorn is x=17. The chromosome ploidy of species and varieties of Crataegus produced in China includes diploidy, triploidy and tetraploidy. Among them, 2n = 2x = 34 include: hawthorn (Figure 1), hairless hawthorn, Hubei hawthorn, Yunnan hawthorn, wild hawthorn, hairy hawthorn, Liaoning hawthorn, light-leaf hawthorn, Gansu hawthorn (Figure 2), Central China hawthorn, etc. The cultivated varieties (series) include Liaohong, Xifenghong, Dajinxing, Soft Seed, Autumn Haw, Qixia Shushahong, Linxian Yuankang Haw, Baiquan 7901, Heze Dashan Haw, Yidu Changkou, Shandong Dahuang Noodle Haw, Chengou Dahong Hawthorn, Jianchang Hawthorn, Fushan Hawthorn, Qianshan Hawthorn, Qixia Venus Mian, Lulong Duanzhi, Pingyi Hawthorn, Yehe Hawthorn, Liaoyang Harvest Red, Anshan Big Venus, etc. 2n=3x=51 include Liaoning Hawthorn, Mopan, and Yubei Red. 2n=4x=68 includes Altai hawthorn (Figure 3).

Figure 2 Cultivation varieties of hawthorn can be divided into two major varieties, yellow and red, according to the color of the fruit. The skin and pulp of the yellow varieties are yellow, and a few of them have reddish skins. Yunnan hawthorn varieties belong to this category. The red variety group has red skin and different flesh colors, and can be divided into red-fleshed varieties, pink-fleshed varieties and green-fleshed varieties. The flesh of red-fleshed fruits is red to purple, such as Liaohong, Xifenghong, Tianshui, Ziyu, Dajinxing, Kaiyuanhong from Liaoning, Luanhong from Hebei, etc. The flesh of pink-fleshed fruits is pink to pink-white, such as Liaoning's Lushan Red, Shandong's Dajinxing, Hongcao Mian, and Qixia Jinxing Mian, Henan's Yubei Red and Linhong (Linxian), Shanxi's Zezhou Red, and Shanxi's Zezhou Red. Yanguohong (Jiangxian County) and so on. Green-fleshed fruits have green to white flesh, such as Mopan hawthorn from Liaoning, Dahao, Changkou, and white-flesh cotton from Shandong.

Figure 3 The cold resistance of various hawthorns varies.

Hawthorn, hairless hawthorn, and long-haired hawthorn can withstand low temperatures of -40 to -50°C. Large-fruited hawthorn can withstand low temperatures of -33°C. Due to its large fruit shape, strong taste, storage resistance and strong adaptability, all the excellent varieties cultivated for production belong to this species. Yunnan hawthorn likes ecological conditions of high temperature and humidity, and has poor cold resistance. In northern areas, it cannot survive the winter in the open air. Although the fruit shape is large, the flavor is not as good as that of large-fruited hawthorn.

Hawthorn, also known as Shanlihong, is an excellent rootstock for hawthorn cultivation in the north. Shrub-type Hubei hawthorn, also known as monkey hawthorn, Gansu hawthorn and Inner Mongolia dwarf hawthorn are all suitable for use as dwarf rootstocks in different regions. Work in this area is still under study. Some types of hawthorn can be used not only as rootstocks for cultivated hawthorns, but also as rootstocks for apples, pears, quinces and loquats, but they are not widely used in production.

General hawthorn seeds are not easily permeable to water, and the embryos are dormant, making them difficult to germinate (see seed treatment). Only the seeds of Altai hawthorn can germinate after a winter of stratification treatment. Extremely useful rootstock germplasm resource. The seed core of soft-seed hawthorn in Liaoning is incompletely developed, very thin and soft, and can be eaten together with the pulp. It is a valuable germplasm for cultivating seedless or soft-seed hawthorn. After the 1980s, China began to carry out character identification and evaluation research on hawthorn germplasm resources.

Although there are over 1,000 described species of the genus Crataegus, most scholars believe that many of them cannot be regarded as species, but are variations or hybrids of some species. The situation is complex and confusing and requires further study and clarification. This situation of high variation is beneficial for the utilization of fruit tree germplasm resources, but it has not received due attention. For example, in the United States, where the species is most widely distributed, it is generally only used as an ornamental plant. There are also species with particularly large fruits. For example, the soft hawthorn (C.mollis Schneid.) has extra large fruits with a diameter of 3 cm; the spotted hawthorn (C.punctata Jacq.) also has a fruit diameter of 2.3 to 3 cm. The Italian hawthorn (C.azazolus L.), native to West Asia and the Mediterranean region of Europe, has few thorns on its tree body and has yellow, red and white fruits with an apple aroma. It is cultivated locally for food and is worthy of attention.