Introduction　　

The origin of the name of peony, according to the "Compendium of Materia Medica", "Peony is also called graceful, beautiful. This grass has a graceful appearance, so it is named after it." Peony has many aliases. In the flower garden with gorgeous flowers, the ancients promoted peony as the "flower prime minister" (the prime minister among flowers), and because peony is a herb, it is also called grass peony (Cui Bao's "Ancient and Modern Notes"). It has large and colorful flowers, charming and varied, so it is named "Jiaorong" and "Yurong" ("Famous Doctors' Records"). In ancient times, people gave peony flowers to each other when they parted to show their farewell.

Because of the love of the peony, it is also known as "Jiangli" and "Licao" (Ancient and Modern Notes). Tang and Song literati called peony "Lanweichun", Lanwei means the last cup, and peony flowers bloom in late spring, which means the last cup of wine in spring. Peony is a herbaceous flower without hard wooden stems, just like a weak willow in the wind, weak and boneless girl, so it is called "boneless flower" (Zheng Qian Hu Materia Medica). Because its flowers are fragrant, it is called "Luanyi (also known as "Hei Qianyi"), "Liuyi" (Guangya Shuzheng) and "Xinyi" (Wang Yi's Notes on Chuci·Nine Songs). In addition, the ancient names include "Jie Cang", "Baizhu", "Li Shi", "Ting" (Famous Doctors' Records), etc. Abroad, peony is also very popular and has the laudatory title of "Queen of Flowers".

　　Peony has been the flower of love since ancient times, and is now also known as the representative flower of the Chinese Valentine's Day.

Peony flowers are not only beautiful, but also can cure diseases. They reflect the Chinese nation's jade-like peony-like virtues and character, hardworking, pragmatic, light as peony fragrance, and soft as jade. Pink peony is like the colorful clouds in the sky, and also like a shy girl in love. The romantic and implicit peony reflects the face of spring. The customs of Shangsi Festival and the love song of "giving a spoon of medicine" have been passed down from the chanting of the Book of Songs to the Han, Tang, Ming and Qing Dynasties. In ancient times, peony has always been the melody of love and romantic folk songs.

　　The flower language of peony is "beautiful and moving", "reluctant to leave, hard to part". In ancient times, men and women would give each other peony as a gift to express their love or farewell, so it is also called "leaving grass".

　　Root: The root consists of three parts: root collar, tuber, and fibrous root. The root collar (different from "rhizome", the root collar is the root, and the rhizome is the stem) is the uppermost part of the root, with a darker color and buds; the tuber grows from the bottom of the root collar, is fleshy, thick, spindle-shaped or long columnar, 0.6-3.5 cm thick, light yellow-brown or gray-purple on the outside, white on the inside, rich in nutrients, the tuber generally does not directly sprout, but can sprout smaller new buds after breaking, so the broken roots of more than 5 cm collected in autumn can also be reproduced; fibrous roots mainly grow from the tuber, are the main organs for absorbing water and nutrients, and can gradually evolve into tubers. The roots of peony can be generally divided into three types according to their appearance: thick root type, slope root type, and uniform root type. Thick root type, the roots are sparse, thick and straight; slope root type, the roots extend to all sides, uneven thickness; uniform root type, the root strips are appropriately dense and uniform in thickness. The root can be used as medicine.

　　Buds: Clustered on the root neck, fleshy, hibernating underground in winter, sprouting out of the ground in early spring as the temperature rises. When they are first born, they are water red to light purple red, and there are also yellow ones. After growing out of the ground, the color deepens, generally becoming dark purple red, and there are scales on the outside to protect them. Peony buds are mixed buds, which develop into both reproductive organs - flowers and nutritional organs - stems and leaves. Before sprouting, the buds are 2.5-4 cm long. The color and shape of the buds after they grow out of the ground will also vary depending on the variety, ranging from dark purple red to yellow brown. The bud shape can be divided into three types: short round, bamboo shoot, and pen tip. Short round, the bud body is short and the end is blunt round; bamboo shoot type, the bud body is long, the end is sharp, like a bamboo shoot; pen tip type, the bud body is long, the end is gradually pointed, like the tip of a brush. Peony sprouting is one of the most spectacular scenes, because it reflects the germination and vitality of life, so it has a high appreciation value.

　　Stem: Clustered from the roots, about 50-110 cm high, herbaceous, cylindrical at the base, angular at the top, some twisted, some straight, and the sunny parts are mostly purple-red.

　　Leaves: The lower part is a two-time three-pinnate compound leaf, that is, the end of the leaf is composed of 3 leaflets to form a leaf bundle, and there is another leaf bundle on each side. Each leaf bundle on both sides is usually composed of 4 leaflets. The compound leaves in the middle, the 3 leaflets at the end remain unchanged, and the number of leaflets on both sides begins to decrease, from the original 4 to 3, 2 or 1, or even disappear. When it disappears, there are only 3 leaflets at the end, which is called a three-time pinnate compound leaf, and the upper leaf is a simple leaf. The leaf is 20-24 cm long, and the leaflets are elliptical, narrowly ovate, needle-shaped, etc. The leaf tip is long and pointed, the entire edge is wavy, and the leaf margin is densely covered with white bone serrations. The leaf surface is yellow-green, green and dark green, and the back of the leaf is mostly pink green, with hair or no hair. The leaves of peony are also ornamental. The "green dragon" in "red lights shining green dragon" is a praise for the leaves, so it can also be used as a foliage plant.

　　Buds: There are several shapes, including round peach, flat round peach, flat round peach, pointed round peach, long round peach, pointed peach, crooked pointed peach, long pointed peach, flat peach, etc. There are 5 outer sepals, leaf-lanceolate, green, decreasing from bottom to top; there are 3 inner sepals (sometimes increasing to 7), green or yellow-green, sometimes with yellow-white stripes or purple-red stripes, obovate, broadly ovate, round, elliptical or irregular.

　　Flowers: usually bloom alone at the top of the stem or near the top of the leaf axil, and some rare species have 2 or 3 flowers at the same time. The original species has white flowers, with a flower diameter of 8--

11 cm, 5-13 obovate petals, many stamens, yellow filaments, shallow cup-shaped disc, covering the base of the carpel, obtuse apex, 3-5 glabrous or hairy carpels, with a beak on the top; horticultural varieties have rich colors, including white, pink, red, purple, yellow, green, black and complex colors, 10-30 cm in diameter, hundreds of petals, some varieties even have 880 petals, and the flower shape varies. Flowering period is May-June.

　　Fruit: Follicle, fusiform, oval, bottle-shaped, etc., smooth, or with fine hairs, with small protrusions. 2-8 pieces are free, composed of a single carpel, with 1 ovary, containing 5-7 seeds.

　　Seeds: Black or dark brown, large, round, oblong or pointed.

　　The period of time during which various organs of peony are restricted by climatic conditions and undergo corresponding changes in a year is called phenological period. For example, in Beijing, peony sprouts and emerges from the ground from the end of March to the beginning of April. The buds that were nurtured in the underground root neck in June and July of the previous year, after growth and flower bud differentiation, sprout and emerge from the ground after the temperature rises in spring. The buds are mostly beautiful purple-red, and a few varieties are delicate yellow-green, which has high ornamental value. After more than 20 days of rapid growth, the height of the new stem can reach about 2/3 of the plant height, the lower compound leaves are flat, and the young leaves are also purple-red or yellow-green; after the lower leaves are flat, they grow rapidly again, and flower buds appear at the top of the stem in early April; after the buds appear, as the stems and leaves are filled, the flower buds develop, and the flowers begin to bloom in early and mid-May; the flowering period ends in early June, and the single flower blooms for 5-7 days, the single-petal variety blooms for a shorter time, and the double-petal variety blooms for a longer time. The flowering period of the group (from the blooming of early-flowering varieties to the withering of late-flowering varieties) is about 25 days; after the flowers wither, the underground root neck differentiates and develops mixed buds; the seeds mature in August, the above-ground parts die in late October to early November, and the mixed buds on the root neck overwinter in the soil, and sprout again in the spring of the following year. This cyclical change process, which takes years as units, mainly has the following rules: first, sequentiality, each phenological period can only proceed under the condition that the previous phenological period is completed, and at the same time it lays the foundation for the next phenological period; second, all changes in phenological periods are produced under the combined effect of certain external conditions, among which temperature is often the dominant factor; third, because the phenological period changes with the changes in the climate throughout the year, therefore, the phenological changes have their annual periodicity; fourth, the phenological period has its recurrence under certain conditions, etc.

　　Main factors affecting flowering phenology

　　(1) Temperature: In the same region, the early and late flowering period of peony is closely related to the temperature changes in spring. Temperature can affect the entire flowering process. The flowering period can differ by 4-5 days or even 10-20 days in warm or cold spring.

　　(2) Water and rainfall: Water and rainfall have little effect on the flowering period. Adequate watering before flowering or rainfall will help the peony bloom, and the flowers will be large and colorful. However, if there is heavy rainfall, the flowers will be damaged and will wither early. If the soil moisture content is low before flowering, the flowers will become smaller, the color will not be bright, and the flowering period will be shortened.

　　(3) Altitude: Altitude can affect changes in temperature, light, and humidity, thus affecting the flowering period. Generally, the flowering period is delayed as the altitude increases. For example, the peony in Luoyang ended its flowering period on May 14, while the peony in nearby Baiyun Mountain in Man County was just beginning to bloom. The peony in Pengzhou City, Sichuan Province, ended its flowering period, while the flowers in nearby Danjing Mountain were just beginning to bloom. The different altitudes of the cultivation site can be used to extend the viewing period.

　　(4) Light: Light often goes hand in hand with temperature and has a significant impact on plant growth and flowering. Insufficient light before flowering will affect the color of the flowers, making them less bright and colorful. Strong light during the flowering period, coupled with rising temperatures, will shorten the flowering period or burn the flowers. Therefore, setting up a sunshade during the flowering period will extend the flowering period of peonies.

　　1. Life cycle and annual cycle

　　Peony is a perennial herbaceous plant with perennial roots. From seed germination to death, it goes through life processes such as growth, flowering, fruiting, aging, and death. This whole process is called the life cycle, also known as the macrodevelopmental cycle. For seedlings, the life cycle can be divided into three developmental periods. Seedlings bloom in about 4 years. Before flowering is the juvenile period. In the first year after sowing, the plant is 3-4 cm tall, with 1-2 leaves, 8-10 cm long roots, and thicker roots at the top, about 0.4-0.5 cm in diameter. In the spring of the second year, the plant is 7-8 cm tall, and the plants with good growth can reach 15-29 cm, with a plant width of about 30 cm. In the spring of the third year, a few plants have already bloomed, with a plant height of 15-60 cm, and only one taproot is well developed; the plant width is 30-40 cm, and all plants can bloom in the fourth year. After entering adulthood, it grows vigorously and blooms luxuriantly, which is the best viewing period. As long as the environment is suitable, the adult period can last for 20 to 30 years, and then enter the aging period until death. The ramet seedlings enter adulthood directly and gradually age after twenty to thirty years.

　　The annual cycle, also known as the small development cycle, refers to the staged development changes of peony plants in a year as the climate rhythm changes. It is mainly manifested in the alternation of growth and dormancy. Among them, the vernalization stage of the dormancy period and the light stage of the growth period are the most critical. The vernalization stage of peony requires about 40 days at a low temperature of 0℃ to complete. Then the mixed buds can germinate and grow. Peony is a long-day plant. The flower buds must develop and bloom under long days. After the mixed buds germinate, if the light time is insufficient, or under short-day conditions, they usually only grow leaves without blooming or bloom abnormally.

　　2. Growth and development characteristics

　　(1) Flower bud structure and life cycle: Peony buds are mixed buds, belonging to the underground bud type. After germination, they extend out of the ground and grow leaves and buds. Mixed buds are a complex of multiple primordia, consisting of the apical growth point, bud scales, axillary bud primordia in the axils of bud scales, leaf primordia, axillary bud primordia in the axils of leaf primordia, bract primordia, sepal primordia, petal primordia, stamen primordia, and pistil primordia. This bud is called the mother bud, and the axillary bud primordia in the axils of bud scales and leaf primordia are the original bodies of daughter buds. The axillary bud primordia in the axils of leaf primordia and the axillary bud primordia do not produce bud scales and are naked buds; while the axillary bud primordia in the axils of scales have bud scales and form scale buds. In spring, scale buds germinate, and the daughter naked buds extend out of the ground along with the internodes of the mother mixed buds, forming flower branches or branches on the main trunk; their daughter scale buds do not extend out of the ground. After the above-ground part withers in autumn, the daughter scale buds located at the top of the root neck of the peony become "terminal buds". In fact, there is only one terminal bud of peony, which is the terminal bud of the seedling after the seed germinates. The next year, this daughter scale bud will sprout out of the soil, stretch branches, unfold leaves, and bloom. Therefore, the life cycle of naked buds is 2 years, while the life cycle of scale buds is 3 years.

　　(2) Flower bud differentiation: After the peony flowers, the axillary buds of its underground scale buds appear in August. The apical growth point gradually produces bud scale primordia from the outside to the inside. By May of the second year, four growth points covered with bud scales have been formed. In late June, the bud scale differentiation is complete. Then, the apical growth point begins to produce leaf primordia, which have multiple finger-like protrusions, while the bud scale primordia have only 1-3. Leaf primordium differentiation ends from early August to early September.

　　1. Temperature

　　Peony is a typical temperate plant that likes warmth and tolerates cold, and has a wide ecological adaptability range. It can be cultivated in the open field in northern regions and has strong cold tolerance.

In Nenjiang County in northern Heilongjiang Province, the annual growing season is only 120 days, and the lowest temperature is -46.5℃, but it can still grow and bloom normally and overwinter in the open field. It is suitable for cool climate in summer, but it is also quite heat-resistant. For example, in Bozhou, Anhui Province, the highest temperature in summer is 42.1℃, and it can safely overwinter.

　　2. Lighting

　　Peony needs sufficient sunlight during its growing period to grow luxuriantly and have bright colors. However, it can also grow and develop normally under light shade. During the flowering period, the temperature can be appropriately lowered and the humidity increased to avoid burns from strong sunlight, thereby extending the viewing period. However, excessive shade will cause excessive growth, weak growth, and failure to bloom or sparse flowering.

　　Peony is a long-day plant. It differentiates flower buds in the short-day season of autumn and winter, and blooms under the long-day season in spring. Both flower bud development and flowering need to be carried out under long-day conditions. If the daylight duration is too short (8-9 hours), it will lead to slow bud development, accelerated leaf growth, poor flowering, or even no flowering.

　　3. Soil

　　Peony is a deep-rooted plant, so it requires a deep soil layer and thick fleshy roots. It is suitable for loose and well-drained sandy loam. It grows poorly in clay and sandy soil. The soil has high water content and poor drainage, which easily causes root rot. Neutral or slightly acidic soil is suitable, and saline-alkali land is not suitable for planting. It grows better in fertile soil, but it should be noted that the nitrogen content should not be too high to prevent the branches and leaves from growing too long. Phosphorus and potassium fertilizers can be appropriately added during the growing period to promote the growth of branches and leaves and beautiful flowers. Peony should not be planted continuously. In traditional peony concentrated production areas, it is a common phenomenon to plant peonies continuously for many years on the same plot of land, which has caused serious losses. Not only are there serious diseases and insect pests, but also the yield and quality have decreased, and even large-scale deaths have occurred. Therefore, a scientific and reasonable rotation system must be implemented.

　　4. Moisture

　　Peonies prefer high and open terrain and a relatively dry environment, and do not need frequent irrigation. Because of their fleshy roots, peonies are particularly intolerant of waterlogging. Waterlogging for 6-10 hours often causes root rot. Low-lying and humid areas are not suitable for peony production areas. Every flood is almost devastating to peonies. Only peonies that are not flooded in high and open areas survive.

　　The traditional propagation methods of peony are: division, sowing, cutting, layering and other methods. Among them, division is the easiest and most widely used. The sowing method is only used to cultivate broken varieties, produce rootstocks for grafted peonies and produce medicinal materials. The rapid propagation of ornamental varieties is an urgent issue to be solved. Tissue culture has always been the hope. A lot of work has been done both at home and abroad. Although there has been progress so far, it is still a long way from practical application.

　　Division is the most commonly used method of propagation for peony. This method is basically used for seedling production in peony producing areas. It has three advantages: first, it blooms earlier than the sowing method. Seedlings bloom in 4-5 years, while division seedlings can bloom every other year; second, division is simple and easy to operate, labor-saving to manage, and conducive to wide application; third, it can maintain the excellent traits of the original variety. The disadvantage is that the reproduction coefficient is low. A three-year-old mother plant can only be divided into 3-5 daughter plants, which is difficult to adapt to and meet the needs of modern large-scale production and the rapidly growing domestic and foreign flower markets. This has always been a major problem that has plagued the production of peony seedlings.

　　1. Division time

　　Theoretically, the division of peony can be carried out from the time when the overwintering buds are full to before the ground freezes. However, if the division is carried out at the right time, the ground temperature is still high, which is conducive to the healing of root wounds, and new roots can be sprouted, which enhances the ability to withstand cold and drought, and lays the foundation for the next year's sprouting and growth. Do not divide the plants too early to avoid autumn flowering, which will affect the growth and development of the following year; do not divide the plants too late, because the ground temperature at that time can no longer meet the requirements of peony rooting, resulting in poor growth of new plants in the next year; if the division is carried out late in spring, the buds will sprout out of the soil, because the temperature in spring is gradually high, the air temperature is low, and the transpiration is large. After the division, the roots are injured and cannot absorb water and nutrients normally, resulting in the growth of the broken plants being very weak or even dead. Therefore, there is a saying in the agricultural proverb that "if you divide the peony at the spring equinox, it will not bloom until it grows old." The suitable time for peony division is generally earlier than that for tree peony. The agricultural proverb in Heze, "Peony in July, peony in August (referring to the lunar calendar month)", means that in Heze, peony can be divided from the end of August to late September (from the beginning of summer to the autumnal equinox). In Yangzhou, division is done from late September to early November. After three or four years of growth, the division seedlings can be divided again. If they are not divided for a long time, the roots will become old, the plants will grow weak, and the flowering will be poor.

　　2. Division method

　　When dividing the plant, carefully dig up the fleshy roots, try to minimize root damage, remove the old soil, cut off the old, hard and rotten parts, and split them along the natural gaps with your hands or a sharp knife. Generally, each plant can be divided into 3-5 daughter plants, each with 3-5 or 2-3 buds; when there are few mother plants and the planting task is large, each daughter plant can also have 1-2 buds, but the recovery growth will be slower, and the thick roots should be retained when dividing the plant. If the soil is moist, the peony roots are brittle and easy to break, so you can dry them for a day before dividing them, dry them in the shade after dividing, and dip them in nutrient-containing mud for planting. In the gardens and green spaces, the peony has been planted for many years, and its growth is gradually weakening and it is urgent to divide it. However, it cannot affect the visitors during the flowering period due to reproduction. The method of on-site division can be used. Use a shovel to dig a deep hole next to the peony plant to expose part of the peony root. Then, use a sharp shovel to cut the peony plant, minimize the vibration of the original plant, take out the cut part, and carry out division and planting. The method is the same as above. Generally, it is appropriate to cut half of the original plant. The deep hole dug can be added with an appropriate amount of fertilizer and soil compaction. You can also use the method of dividing the rows or every other plant. In this way, the division can be rejuvenated without affecting the landscape. It only takes 2-3 consecutive years of division. However, because peony is not suitable for continuous cropping, the method of dividing the rows or every other plant cannot be used continuously, otherwise the disease and insect pests will be serious, the growth will be poor, and even the mortality rate will increase greatly.

　　When peony is cultivated for medicinal purposes, peony producing areas mostly use peony heads for division and propagation. In autumn, the mother plant is dug out, and all the thick roots are cut off for medicinal use, while the peony heads with buds are used as propagation materials. First, remove the peony heads without buds and diseased feet, and cut the peony heads into blocks, each with 2-3 strong buds. The thickness of the peony heads is 2 cm. If it is too thick, the taproot will not be strong and will have many forks. If it is too thin, the nutrients will be insufficient. It is best to plant as soon as it is divided. If it cannot be planted in time, do not divide it. The peony heads can be stored in the sand for later use. It is suitable for planting from early August to late September.

　　3. Management after division

　　The planting depth should be about 2 cm when the buds are planted into the soil. Too deep is not conducive to germination and is prone to root rot, yellowing of leaves, and poor growth. Too shallow is not conducive to flowering and is prone to frost damage, and even the rhizome head is exposed to the ground and exposed to the scorching sun in summer, resulting in death. If the root cluster of the ramet is large (with 3 to 5 buds), it may have flowers in the second year, but the shape is small, so it is better to remove them to make the plant grow well. If the root is small (2 to 3 buds), it will grow poorly or not bloom in the second year, and generally needs to be cultivated for 2 to 5 years.

　　The fruit of peony is a follicle, each containing 1-7 seeds. When the seeds mature, the follicles split open and the seeds are released. The fruit maturity period varies from place to place.

For example, in Mudanjiang, Heilongjiang Province, in early September, in Heze, Shandong Province, in early to mid-August, and in Yangzhou, Jiangsu Province, in late August. Seeds should be sown immediately after harvesting. As the sowing time is delayed, the moisture content of the seeds decreases and the germination rate decreases. Seeds have dual dormancy characteristics of the upper and lower hypocotyls. The soil temperature in autumn after sowing causes the hypocotyls of the seeds to break the dormancy state, and the radicle develops and takes root. The better the rooting situation in the current year, the more vigorous the growth in the next year; if the sowing is too late, the ground temperature cannot break the dormancy of the hypocotyls, and the seeds cannot grow well, and the germination rate in the spring of the second year is greatly reduced. After sowing and rooting in autumn, the dormancy of the upper hypocotyls can be broken after a long period of low temperature in winter. When the temperature rises in the spring of the following year and the humidity is suitable, the embryo will emerge.

　　Because the offspring produced by sowing peony horticultural varieties will have separate characteristics and cannot maintain the excellent characteristics of the original variety, the sowing method cannot be used for the reproduction of variety seedlings.

　　1. Seed harvesting

　　When the follicles turn yellow, they can be harvested. If harvested too early, the seeds will not mature. If harvested too late, the seed coat will turn black and hard and it will be difficult for the seedlings to emerge. The fruits mature at different times, so they should be harvested in batches. When the peel cracks and the seeds are released, they can be sown. Do not expose the seeds to the sun, as this will harden the seed coat and affect germination. If sowing is not possible in time, the seeds can be stored in sand for moisture preservation, but they must be taken out and sown before the seeds take root.

　　2. Sowing time

　　Peony seeds must be sown in the same year. For example, in Heze, sowing is done from late August to late September. If it is done later than late September, it will not take root in the same year, and the germination rate will be greatly reduced in the spring of the following year. Moreover, even if the seedlings emerge, they are difficult to resist the spring drought due to their underdeveloped root system and are prone to die. Therefore, Heze has failed in several spring sowing experiments.

　　3. Sowing method

　　Seed treatment: Before sowing, remove the shriveled seeds and impurities, and then use water selection to remove the unfilled seeds. Although the seed coat of peony seeds is thinner than that of peony seeds and is easier to absorb water and germinate, if the seeds are treated before sowing, the germination will be more uniform and the germination rate will be greatly improved, often reaching more than 80%. The method is to soak the seeds in 50℃ warm water for 24 hours, and then sow them after taking them out.

　　Preparation and sowing: The land for sowing and seedling raising should be fertilized with sufficient base fertilizer, and the soil should be deep-turned and leveled. If the soil is relatively moist and suitable for sowing, it can be directly sown in the ridges; if the soil moisture is poor, it should be fully irrigated, and then sown in the ridges. The width of the ridge is about 50 cm, the distance between the ridges is 30 cm, and the seeds are sown at a row spacing of 6 cm and a grain spacing of 3 cm; if there are enough seeds, it is feasible to withdraw the seeds, and the grain spacing is not less than 3 cm; after sowing, cover with wet soil with a thickness of about 2 cm. About 50 kg of seeds are used per 666.7 square meters, and about 100 kg are sown. Cover with mulch after sowing, and remove it after germination in the spring of the following year. It is also feasible to sow in rows, with a row spacing of 40 cm, a grain spacing of 3 cm, and a covering of 5-6 cm; or row and hole sowing, with a hole spacing of 20-30 cm, 4-5 seeds are placed in each hole, and the soil is piled up 10-20 cm after sowing to prevent cold and retain moisture. Harrow it before germination in the spring of the following year.

　　1. Cutting method Choose a nursery with high terrain and good drainage as the cutting bed. After the bed soil is loosened, spread 15 cm thick river sand. The river sand should be disinfected with 0.5% potassium permanganate. Vermiculite or perlite can also be used as the cutting medium. Build a 1.5-meter-high sunshade on the bed. According to the experience of Changchun and other places, the best effect of cutting cuttings is to cut cuttings in mid-July. The cuttings are 10-15 cm long. Lead the first node, the upper compound leaf, leave a few leaves; the lower compound leaf, including the petiole, and quickly dip it in a 500X10-1000X10 naphthaleneacetic acid or indoleacetic acid solution for cutting. The cutting depth is about 5 cm, and the spacing is based on the leaves not overlapping each other. After inserting, water thoroughly and cover with a plastic shed. It has been observed that the rooting effect is best when the substrate temperature is 28-30℃ and the humidity is 50%. Keep the temperature in the cutting shed at 20℃-25℃ and the humidity at 80%-90%. Then the cuttings will take root and form dormant buds 20-30 days after taking root.

and watering amount, and gradually remove the plastic shed and sunshade. Cutting seedlings grow slowly and need to be covered with soil on the bed for wintering, and then moved to the open field for planting in the spring of the following year.

　　2. The root cutting method is to use the roots of peony when it is divided in autumn, cut them into 5-10 cm root segments, and insert them into a deep and leveled trench with a depth of 10-15 cm. Cover them with 5-10 cm thick fine soil and water them thoroughly.

　　3. Layering method: In spring, the tender buds that have just sprouted out of the soil are passed through the holes in the pot and introduced into a pot with a diameter of 15-20 cm. As they grow, the soil is gradually filled in and the potting soil is kept moist. They will take root in summer. Before winter, cut off the stems under the pot to form a potted peony.

　　4. Modern tissue culture method Plant tissue culture is a plant aseptic culture technology. It is based on the theory that plant cells have omnipotence. It uses the organs, tissues or cells (such as roots, stems, leaves, etc.) of peony in vitro to induce callus, adventitious buds, adventitious roots under sterile and appropriate artificial culture medium and light, temperature and other conditions, and finally forms a complete plant with the same genetic characteristics as the mother. This technology is also called cloning technology, which achieves the purpose of rapid reproduction and has the value of wide application.

　　There are many types of peony cultivation, including ornamental cultivation, medicinal cultivation, soilless cultivation, promoting and inhibiting cultivation, cut flower cultivation, etc., which are described below.

　　1. Land use requirements

　　The planting site should be a high, dry, well-drained area with a deep, loose and fertile sandy soil. When planting in areas with heavy salinity, the soil needs to be replaced; when planting in low-lying areas, a high platform should be built, and there should be sufficient clean irrigation water. Peony should not be planted continuously. Field cultivation generally rotates once every 3-4 years, otherwise the growth will be weakened and pests and diseases will cause serious damage. When it is not possible to rotate on time due to land limitations, deep plowing should be carried out 1-2 months before planting. The depth is 60-100 cm. 1500-2000 kg of decomposed dry manure or 200-250 kg of cake fertilizer can be applied per 666.7 square meters. Remember not to apply unrotated raw fertilizer.

　　2. Planting period

　　Whether it is sowing seedlings or dividing seedlings, the planting time is from late August (End of Heat) to late September (Autumnal Equinox) in Heze, and from late September (Autumnal Equinox) to early November (Beginning of Winter) in Yangzhou. Generally, it is combined with division.

　　3. Planting specifications

　　The row spacing for ornamental cultivation in the garden can be 1 meter × 1 meter, and the planting points can be arranged in a "pink shape". This planting can evenly and reasonably use the land and is conducive to the uniform growth of the plants, but field operations are sometimes inconvenient. In order to facilitate field management and observation and recording, a "square shape" arrangement method with horizontal and vertical rows is often used. The specifications of the planting hole are about 35cm deep and 18cm in diameter at the top. The pit should be narrow at the top and wide at the bottom. The thick roots are not removed for ornamental cultivation and propagation. For medicinal cultivation, the root-promoting seedlings after root removal are used (the method in Dongyang, Zhejiang), and the hole is about 25 cm bare. If the rooted peony head is directly used for planting, the depth can be shallower.

　　4. Planting method

　　Apply well-rotted dry manure or cake fertilizer to the bottom of the hole. Mix it with the subsoil. Before planting, treat the peony seedlings with a mixture of 700 times thiophanate-methyl and 1000 times methyl isoflavone to prevent pests and diseases. Hold the peony seedlings and place them in the hole with the roots spread out. When the soil is filled to half of the pit, shake and lift the seedlings to make the root system tightly combined with the soil. The height of the seedlings is based on the level of the buds and the ground. After watering, the pit sinks, which is just the appropriate planting depth. If the planting is too deep, the buds are not easy to sprout out of the soil. Even if the seedlings emerge, the growth and development are not vigorous; if the planting is too shallow, the rhizomes are exposed to the ground and are exposed to the sun in summer, which can easily lead to death. Finally, fill the soil until the hole is full, tamp it, and pile up a pile of about 10 cm to prevent cold and pick, and also serve as a mark and protection. Depending on the soil moisture, if the soil is moist, you don’t need to water after planting. Generally, you should irrigate after planting.

　　5. Field management

　　(1) Digging up the soil and leveling the ridge: In the autumn of the previous year, the soil piled up during planting must be leveled in time before the peony buds emerge from the soil to make the ridge surface smooth, so as to facilitate watering and field management. If the operation is done too late, digging up the soil will damage the buds; if the soil is not dug up, the base of the buds will be weakened, affecting growth.

　　(2) Intertillage and weeding: Intertillage and weeding should be carried out frequently throughout the growing season. Deep tillage should be carried out before the leaf curtain completely covers the ground and before and after flowering; shallow tillage should be carried out after flowering. Generally, intertillage and weeding should be carried out about 10 times a year.

　　(3) Fertilization: Peonies like fertilizer and rarely suffer from excessive fertilizer. Especially when the flower buds are translucent and buds are forming, the demand for fertilizer is more urgent. In addition to applying base fertilizer during planting, topdressing can be applied three times a year according to the fertilizer requirements of the peony at different development stages. In spring, after the seedlings emerge from the soil and their leaves unfold, "flower fertilizer" can be applied to promote the plant's vigorous growth and add a large amount of fertilizer for the development of flower buds and flowering. In order to replenish fertilizer in time, use more quick-acting fertilizers and pay attention to appropriately increase the amount of fertilizer.

The composition of phosphorus and potassium fertilizers. After flowering, a large amount of nutrients in the body are consumed, and flower bud differentiation and bud development are required. "Bud fertilizer" can be applied. Whether there is sufficient fertilizer supply in time at this time is directly related to the quality of flowering and growth in the next year. Quick-acting fertilizers should still be applied. Before winter, combined with wintering, "winter fertilizer" can be applied, mainly long-acting fertilizers, mostly fully decomposed compost, stable manure, or decomposed cake fertilizer and compound fertilizer.

　　There are three methods of topdressing: hole application, furrow application and general application. For one- or two-year-old seedlings, because the root system is not well developed, the method of inter-plant hole application or inter-row furrow application is often used. The depth of the hole and furrow is about 15 cm. Fertilizer is applied in it and covered with soil. For plants over three years old, general application is mostly used. After spreading the fertilizer evenly, it is combined with inter-cultivation and weeding, deep hoeing and loosening the soil to mix it with the soil. For one- or two-year-old seedlings, 150-200 kg of cake fertilizer or sesame paste residue (the sauce after making sesame paste) or 1,500 kg of manure can be applied per 666.7 square meters. For plants over three years old, 200-250 kg of cake fertilizer or sesame paste residue can be used per 666.7 square meters, or 2,000-2,500 kg of manure can be used.

　　(4) Watering: Peonies have a well-developed root system that goes deep into the soil and can absorb water from deep layers of the soil. Their fleshy roots are not tolerant to water and humidity, so they do not need to be watered as often as open-field flowers. However, excessive dryness is also detrimental to their growth, and the flowers are small and sparse, and the color is not bright. It can be seen that moderate moisture is an ecological condition necessary for the normal growth of peonies. Therefore, they still need to be watered in a timely manner even when it is dry, especially before and after flowering and before covering the soil for wintering. Sufficient irrigation must be ensured. When it rains heavily, special attention should be paid to timely drainage to avoid damage to the root system.

　　(5) Removing side buds: In addition to the main buds on the top of the stem, peony has 3-4 side buds in the axils of the upper leaves of the stem. In order to concentrate nutrients and make the top buds larger, the side buds should be removed shortly after the flower buds appear. To prevent the top buds from being damaged, one side bud can be left first. When the top buds swell and develop normally without problems, the reserved side buds can be removed. Therefore, flower growers have the saying "peony is headed (side buds removed), peony is footed (foot buds removed)". By cleverly using the difference in the flowering period of the main and side buds, the viewing period of peonies can be appropriately extended. You can select some plants of the same variety (varieties with side buds that can bloom normally), remove the main buds, and leave one side bud to bloom, so that the flowering period can be delayed by several days.

　　(6) Support pillars: Peony peduncles are relatively soft. Except for a few varieties with short and strong plant types and varieties with fewer petals such as single-petal, lotus-shaped and golden-stamen-shaped varieties, most varieties have flower heads drooping sideways when blooming, or even the entire plant lying on its side. To maintain a good ornamental effect, after the buds have turned color, support pillars should be set up to make the peduncles straighten, the flower heads stand upright, and the flowers look beautiful. There are two common types of support pillars: the first is the single-pillar type, which is mostly used for varieties with extra-large flowers and soft stems. When tying, insert a thin bamboo into the soil on the back of the flower stem, and then use a plastic rope or hemp rope in the shape of an "8" to tie the upper part of the flower stem to the support pillar 6-8 cm away from the flower head. Do not tie it tightly to the top of the flower stem to avoid making the flower head stiff and losing its beauty. The second type is the bamboo ring type, which is used for general varieties. Loose clusters are surrounded by bamboo rings. At this time, the surrounded flower stems rely on each other to stand upright. The size of the bamboo ring can be adjusted according to the size of the cluster. Generally, two layers of bamboo rings are used, with the lower layer being small and the upper layer being large. Each bamboo ring is tied and fixed with 3 or 4 small bamboo poles inserted in the soil. The above two forms can be used in combination according to the situation.

　　(7) Set up a sunshade and rainproof shed: Peony flowering period coincides with the hot and rainy season. During the flowering period, a sunshade and rainproof shed can be set up to block out the strong winds, reduce humidity, and protect against rain, so as to improve the viewing effect and extend the viewing period. The shed is 2.5 meters high and covered with a sunshade net and plastic film. Setting up a shed can extend the flowering period by 8-10 days.

　　(8) Cut off the remaining flowers: After flowering, except for those left for planting, cut off the remaining flowers in time to avoid wasting nutrients.

　　(9) Cut off the above-ground parts, irrigate with freezing water, and cover with soil for winter: After late October, the above-ground stems and leaves gradually turn yellow and dry. At this time, the dead leaves should be cut off, swept away, and buried deep to prevent the spread of pests and diseases. Then, before the soil freezes in winter, water thoroughly, apply fertilizer, and pile up soil to retain moisture and protect against cold for winter.

　　Peony is commonly used for medicinal cultivation. It is a traditional Chinese medicine. The root bark is scraped off and it is called "white peony". Some wild peony plants, such as Sichuan red peony (P. vitchii) and grass peony (P. obovata), are generally not scraped off when used for medicinal purposes and are called "red peony". Both are used as medicine but have different medicinal effects.

　　Medicinal cultivation is similar to ornamental cultivation, but there are also differences. The planting spacing is 50 cm x 40 cm or 50 cm x 35 cm, that is, 3000-3500 plants are planted per 666.7 square meters. It can be planted in holes or furrows. The seedlings to be planted are ramet seedlings or three-year-old sowing seedlings. If they are ramet seedlings, the new plants should not have too many buds. They can have 1-3 buds and 2 roots. If they have 1 bud and 1 root, 2 plants can be planted in each hole. Too many buds will cause the branches and leaves above the ground to grow too long, affecting the growth of the root system. The purpose of medicinal cultivation is to cultivate good roots, so that the roots develop quickly and grow fully. When the plants show buds, they will be removed completely to prevent them from developing and flowering, so that nutrients can be concentrated on the growth of the roots. It is best to pick the buds on a sunny day without dew. After picking the buds, spray the equal amount of Bordeaux liquid once to reduce bacterial infection.

　　After taking the peony root from the peony plant, remove the whiskers, classify it according to different thicknesses, boil and stir, take out the root and observe, if all the water marks are dried in less than 1 minute, it is the right time (some say take out the root, when there is no water droplets on the root skin, it is the right time), take it out immediately and soak it in cold water for about half an hour or more, and then cover it with a glass

, knife, etc. to scrape off the root bark, wash and dry. It is best not to expose it to the sun, so as not to turn the outer skin reddish brown. It needs to be dried for about half a month. Thick roots need more time, while thin ones need less time. During the root drying process, dry it for a few days, collect it together and keep it for one or two days to make it damp, and then dry it again until the roots break and turn pink and make a sound when knocked. Then they can be graded and packaged for sale. Usually, they are divided into three grades according to the root diameter: first-grade products, with a root diameter of more than 4 cm, second-grade products, 2-4 cm, and third-grade products, less than 2 cm. All require smooth outer skin, white with pink, and uniform thickness. Generally, 1 kg of fresh white peony can obtain 0.5 kg of dry white peony. After 3 years of continuous cultivation, about 900 kg of fresh roots are produced per 666.7 square meters, and 450 kg of white peony is produced (Heze). The method of making white peony in Dongyang, Zhejiang is to remove the root bark first and then boil it. It is a method with local characteristics, but the medicinal effect is the same.

　　Soilless cultivation, also known as hydroponics, is a technology that uses nutrient solution prepared according to the nutrients necessary for plant growth and development to cultivate plants. For the export of potted flowers in the international flower market, soilless cultivation must be used to prevent the spread of pests and diseases. Because it saves water and fertilizer, is clean and hygienic, has fewer pests and diseases, has good product quality, and saves labor in management, it is increasingly widely used.

　　1. Variety selection

　　Most peony varieties perform well in nutrient solution cultivation, and are better than general soil cultivation. Varieties suitable for soilless cultivation include "Purple Butterfly Offering Gold", "Oolong Holding Sheng", "Cinnabar Plate", "Yang Fei Out of the Bath", and "Inkstone Pool Waves".

　　2. Matrix preparation

　　Peony has fleshy roots, and the substrate requirements are good air permeability, fertilizer retention, and water retention. Vermiculite, perlite, ceramsite, and bark can be used as substrates. Mixed substrates have better effects. The proportions are as follows: vermiculite, perlite, and bark are mixed in a ratio of 1:1:1; vermiculite, perlite, and ceramsite are mixed in a ratio of 1:1:1; or vermiculite and perlite are mixed in a ratio of 1:1. In the south, some local substrates can be added, such as carbonized rice husks.

　　3. Cultivation form

　　There are two forms of potted planting and trough planting. For potted planting, the size of the peony plant should be selected according to the size of the flower pot. Clay pots can be used, which have good ventilation and are conducive to plant growth, but they are heavy and inconvenient to manage and use. Plastic pots are commonly used, which have beautiful appearance, light weight, and are easy to use and manage, but have poor ventilation. When planting, a layer of ceramsite is laid on the bottom of the pot to facilitate drainage, and then the peony seedlings are planted, and the mixed matrix is ​​filled in. A layer of ceramsite can be added to the surface to prevent the matrix from splashing out when watering. For trough planting, cement or bricks can be used to build a rectangular cultivation trough with a certain drainage slope on the long axis, about 80-120 cm wide, 200-300 cm long, and 42 cm deep. Plastic film is laid in the trough, and a 40 cm thick cultivation matrix is ​​filled in. The seedlings are planted with a row spacing of 40 cm × 40 cm, and 2-3 rows can be planted. The planting time is the same as the field planting time.

　　4. Preparation of nutrient solution

　　Wang Yueying and others from Beijing Forestry University have formulated nutrient solution formulas suitable for three different growth periods by analyzing the nutritional status of peony cultivation soil and determining the nutritional content of peonies in different growth periods: first, it is used from summer to before winter to promote buds and protect roots; second, it is used before flowering, with a high phosphorus content, which promotes beautiful and large flowers; third, it is used after flowering to play a comprehensive fertilization role. This has a high reference value for the preparation of nutrient solution for soilless cultivation of peonies. The mineral element content of the nutrient solution should be between 0.1% and 0.4%.

　　5. Irrigation system

　　There are several irrigation methods:

　　(1) Gravity irrigation facilities: commonly used in general production and cultivation, with simple installation, low investment, convenient management and good use effect. The width of the cultivation trough is 200 cm, and 4 drip irrigation belts can be installed. The size of the nutrient solution storage tank depends on the area of ​​the cultivation trough. Generally, the storage tank can be 150-200 cm higher than the surface of the cultivation trough. The gravity generated by the height difference of the liquid is used to deliver the nutrient solution to the roots of the plants through the drip irrigation pipe.

　　(2) Power irrigation facilities: mostly used for large-scale soilless cultivation. The nutrient solution delivery in the above facilities is changed from gravity delivery to power delivery. An electric pump is added as the delivery power.

　　(3) Micro-tube sprinkler irrigation facilities: Plastic tubes with many micro-holes are laid on the bed surface to spray the nutrient solution onto the cultivation bed.

　　(4) Seepage pipe irrigation facilities: Specially made seepage pipes are buried 2-10 cm into the substrate to allow the nutrient solution to continuously seep outward. This can save water, ensure uniform irrigation, and is also very convenient to operate.

　　6. Cultivation and management

　　After the peony seedlings are planted in the cultivation trough in autumn, they can be irrigated with nutrient solution once every 10 days. Generally, it is prepared into a 1000-fold nutrient solution mother solution, which is diluted when needed. By the end of November, the peony begins to shed its leaves, and the nutrient solution is stopped, and only water is applied. Pour enough frozen water before winter. After budding in early spring, start to irrigate with nutrient solution once every 7 days, and once every 5 days before and after flowering to ensure adequate nutrient supply. After flowering, cut off the remaining flowers in time to prevent fruiting. At different stages of growth and development, the nutrient solution formula should be adjusted accordingly according to the different nutritional needs of the plants, and other management is the same as ornamental cultivation.

　　The cultivation method of using artificial measures to promote the early germination of peony flower buds and blooming earlier than the natural flowering period is called forced cultivation. On the contrary, the cultivation method of using artificial measures to delay the germination of flower buds and bloom later than the natural flowering period is called inhibition cultivation. Both are often called delayed flowering period. On the basis of the natural flowering period in the open field, the flowering period can be reasonably controlled by the means of forced and inhibited cultivation, so that the peony can bloom all year round.

　　The beginning of flower bud differentiation of peony is later than that of tree peony; its early-flowering varieties begin flower bud differentiation at the end of August, while late-flowering varieties start as late as mid-to-late September.

From mid-April, the petal primordium is formed and the development stops, and the flower survives the winter in this state. In the spring of the second year, the flower buds continue to develop and bloom.

　　In order to ensure the year-round supply of cut and potted peony flowers, a combination of promoting and inhibiting cultivation is often used to regulate the flowering period. Selecting suitable varieties and strong seedlings with fully developed flower buds and pure varieties; adopting scientific treatment measures and careful cultivation management are the guarantees for the success of promoting and inhibiting cultivation.

　　1. Forcing cultivation

　　(1) Variety selection: When cultivating peony, we must first select varieties that are suitable for forced cultivation. Generally, early-flowering varieties are selected, which can shorten the time of flowering, such as "Qiaoling", "Mozilou", "Yinhe", "Fenronglian", "Dafugui", "Fengyu Luojinchi", "Meiju", etc.

　　(2) Cold storage: In order to make the peony bloom before the natural flowering period, three or four-year-old strong plants should be selected for cold storage. In the cold storage room, use the soil burying cold storage method, and the buds are slightly exposed. During the cold storage period, check the soil humidity once every half a month. If sandy loam is used, it is best to check the soil humidity just enough to hold it in a ball. Too dry is not good for flowering, and too wet is easy to cause mold and root rot. The humidity in the cold storage room should be maintained at 3°C. Different varieties have different treatment humidity and treatment time. If the plants are refrigerated in early September and then transplanted, at 15°C, they will bloom in 60-70 days, that is, they can be put on the market in December; if they need to bloom in January or February of the following year, they can be refrigerated in October or November.

　　(3) Planting in nutrient soil: Plants that have been refrigerated need to be planted in nutrient soil and regularly sprayed or irrigated with nutrient solution, supplemented with hormone management, and special attention should be paid to spraying fertilizer in the later stage. The nutrient soil can be made of decomposed leaf mold, garden soil and sandy soil in a ratio of 2:3:1, and an appropriate amount of cake fertilizer and phosphorus and potassium fertilizers should be added. Nitrogen fertilizer should be applied after potting. After taking the plants out of the cold storage, they should be placed in a cool place to adapt to the room temperature. When potting, the soil should be 1 cm higher than the buds, and the buds should be slightly exposed after watering.

　　(4) Adjustment of temperature and humidity: After the flowering plants enter the wet room, gradually increase the temperature. The most suitable growth temperature for peony is 20℃-25℃. Above 30℃, it is not conducive to growth. The following temperature control methods can be used: 15℃-20℃ in the early stage, about 10 days; 15℃-25℃ in the middle stage, about 15 days; 20℃-25℃ in the late stage, about 20-25 days. The high temperature should not exceed 28℃, the low temperature should not be lower than 12℃, and avoid drastic temperature changes. The relative humidity of the air should be maintained at 70%-80%, which can be adjusted by watering, spraying, ventilation, etc.

　　(5) Supplementary light: Peonies prefer warm and sunny weather. During the winter and spring seasons when they are forced to grow, supplementary light is particularly important. The number of hours of light should be increased to 13-15 hours per day to allow the flower buds to fully develop and the flowers to bloom beautifully and large.

　　(6) Hormone application: Generally, gibberellin (GA3) is used for treatment. When watering after potting, 2000 mg/L GA3 can be used for treatment to further break the dormancy of the buds. When the buds are 0.4 cm and 0.8 cm in diameter, 600 mg/L GA3 is applied to the buds twice; when the buds are 1.2 cm in diameter, 1000 mg/L GA3 is applied once.

　　(7) Other management: When the buds grow to 5-10 cm, remove the buds without buds to avoid wasting nutrients. In the future, pay attention to removing the lateral flower buds, leaving 6-8 flowers per plant. When the flower buds are about to bloom, watering should be controlled for sale or rental. Do not water the flowers after flowering. Place them in a room at 15℃-20℃, and the flowering period can reach 20-30 days. After the flowers fade, put them back in the room and plant them back in the open field when the temperature is suitable. If used as cut flowers, harvest them as usual and continue to manage them carefully to nourish the roots and promote buds for future use.

　　2. Suppress cultivation

　　For suppression cultivation, late-flowering varieties are often used. The following varieties can be considered: "Yang Fei Emerging from the Bath", "Linglong Jade", "Ice Green", "Zhao Garden Powder", "Inkstone Pool Rippling Waves", "Red Goose Flying Box", "Flower Red Tower", "Silver Needle Embroidered Red Robe", etc.

　　In order to make the peony bloom later than the natural flowering period, two measures can be adopted

　　(1) Cold storage during dormancy: In early spring, dig up the plants that have not yet sprouted and store them in a cold storage at 0℃ for later use, keeping the plants moist. Depending on the time of use, they can be taken out of the warehouse 30-45 days in advance and cultivated normally, and they will bloom in time.

　　(2) Refrigeration during the growth period: The buds can be refrigerated when they are about to open. The refrigeration temperature should be higher, 3-5°C, and the refrigeration temperature should be kept until 2-3 days before the flowers are used, and then they can be taken out of the warehouse for conventional cultivation.

　　The latter method can only be refrigerated in the warehouse for a short period of time, which can be used to extend the normal viewing period. Long-term refrigeration will lead to leggy growth and reduced ornamental value. With the former method, if it is planted in April-August, it will bloom in 30-35 days; if it is planted in March or September, it will bloom in about 45 days. When the temperature is too high in midsummer, shading can be carried out, and water spraying can be used to cool down to prevent the high temperature from causing bud shrinkage and leaf burns.

　　Peony(5 photos)

　　At present, the sales of cut flowers account for about 60% of the total sales in the world flower market. Peony cut flowers have become popular in the world flower market because of their large and colorful flowers, long stems, water resistance, and easy storage and transportation. A certain amount of peony cut flowers are exported every year, and the development prospects are very promising. The following measures should be taken for cut flower cultivation:

　　1. Select varieties suitable for cut flower applications

　　The existing varieties are all bred for garden cultivation, and there are no varieties specifically bred for cut flower production.

Some varieties suitable for cut flower applications can still be selected. Varieties suitable for cut flower production should meet the following conditions:

　　(1) The flowering rate is high, the flowers are abundant, the pedicels and petioles are stiff, the branches are long, and the leaves are small.

　　(2) The flowers are neatly shaped, colorful, fragrant, with round buds that are not prone to cracking.

　　(3) The petals are hard and well-layered, the flower diameter is medium, the flowers open upward, and the buds secrete little sugar.

　　(4) Cut flowers grow well in water and have a long water-growing period.

　　(5) The plants grow vigorously, have strong growth potential, strong sprouting ability, strong resistance to stress, few diseases and insect pests, and are resistant to storage and transportation.

　　After experiments, 8 varieties for cut flowers were selected according to the above standards, namely "Da Fugui", "Qingyunhong", "Gaoganzi", "Liantai", "Qiaoling", "Qihualushang", "Zhongshengfen" and "Zihongkui".

　　Famous Japanese cut flower varieties include "May", "Huazhu no Dian", "Chijinpan", "Boyun", etc., and famous European and American cut flower varieties include "Fosiva maxima", "Nanette", "Alice Crousse", etc.

　　When choosing cut flower varieties, attention should be paid to the combination of flower color and flowering period to ensure that they can be supplied to the market throughout the year or for multiple seasons.

　　2. Field management

　　(1) Choose a place with high and dry terrain, convenient irrigation and drainage, sufficient sunshine, thick soil, sheltered from the wind and facing the sun, and neutral or slightly acidic sandy loam as the land for cut flower cultivation. Peony likes fertilizer, so apply a large amount of organic fertilizer, pay attention to increasing the content of phosphorus and potassium fertilizers, and do not apply too much nitrogen fertilizer, so as not to cause excessive growth and affect the quality and quantity of cut flowers.

　　(2) For peony cut flower cultivation, it is advisable to plant about 2,500 plants per 666.7 square meters. The plant spacing can be 40 cm x 60 cm. Rationally irrigate and fertilize, and prevent and control diseases and insect pests.

　　(3) When the cut flowers are in full color, keep the lower 2-3 compound leaves and cut them off to allow photosynthesis to continue and promote flower bud differentiation. Spray 200 mg/L of gibberellin (AG3) solution 15-20 days before flowering to help the flower stems elongate and the flowers become brighter in color.

　　3. Post-harvest management

　　(1) Cutting at the right time: When the flower buds are translucent, keep the lower 2-3 compound leaves and cut off the flower branches. The best time to cut is from early morning to 10 am. If the cutting task is large, it can also be done in the evening. After cutting the flower branches, put them in a bucket of clean water immediately to prevent water loss.

　　(2) Grading and packaging: Remove the leaves and grade the flower branches in a low-temperature room. Cut off the two compound leaves on the top and the single leaves near the flower buds. Cut off the remaining compound leaves from the base of the petiole. Wash off the sugar liquid secreted on the flower buds with clean water. The flower branches are divided into five grades according to their length: 50 cm, 55 cm, 60 cm, 65 cm and 7 cm. Wrap each flower bud with soft paper first, and then put it in a corrugated paper tube. According to the variety and the length of the flower branches, 10 branches are tied into a bundle, and then cut at the base according to the length requirements. The base is immersed in 4 mmol/L STS (silver thiosulfate) solution for pretreatment for 10 minutes; then dip it in the fungicide solution at a medium speed, and when it is dried until there are no water droplets on the leaves, the bundled peony cut flowers are packed and shipped out.

　　(3) Storage and preservation: Based on the research on the post-harvest physiology and preservation technology of cut flowers, in order to extend the life of cut flowers, three major problems must be solved, namely, supplying necessary nutrients, preventing duct blockage, and inhibiting the synthesis of ethylene.

　　Peony cut flowers cut at the bud stage are treated with STS for 24 hours, then dry-stored in a cold storage at 0-2℃ for 3 months. After being taken out and treated with preservative liquid, they still have a water-cultured lifespan and ornamental value similar to that of fresh cut flowers.

　　The main diseases of peony are peony gray mold, peony brown spot and peony red spot.

　　1. Scarab

　　Pest types and damage: There are many types of beetles that harm peony, such as the black velvet gill beetle, apple beetle, yellow hair gill beetle, etc. The adults harm the leaves and flowers of peony; the larvae are grubs, with a nearly cylindrical body that bends into a "C" shape, milky white, with a yellow-brown head, 3 pairs of thoracic legs, and no abdominal legs. They feed on the roots of peony, and the wounds caused create conditions for the infection of Fusarium, leading to the occurrence of root rot.

　　2. Scale Insects

　　(1) Pests and damage: Scale insects are also known as scale insects. There are several species of scale insects that harm peony, such as the cotton scale, Japanese wax scale, Changbai shield scale, mulberry white shield scale, peony round scale, arrow-pointed shield scale, etc.

　　Scale insects suck the body fluids of peony, causing the plant to grow weak and the branches and leaves to turn yellow.

　　(2) Prevention and control methods

　　① Strengthen quarantine and strictly prevent the introduction of insect-infested seedlings

　　② Protect and utilize natural enemies.

　　③ Spray the insecticide during the peak hatching period. The surface of the newly hatched insects is not yet covered with wax and is easy to be killed.

　　Peony(3 photos)

　　You can spray 40% omethoate 1000-1500 times liquid, or 50% malathion emulsion 800-1000 times liquid, or 50% phoxim emulsion 1000-2000 times liquid. Spray the medicine evenly and spray the whole plant. Spraying the medicine after the wax shell is formed is ineffective.

　　④ Use furandan liquid to irrigate the root zone. The plants absorb the medicine and the insects are poisoned after sucking the plant body fluid.

　　⑤ When you find that individual branches are damaged by scale insects, you can use a soft brush to brush them off, or cut off the infested branches and burn them.

　　3. Aphids

　　(1) Damage situation Peonies are often damaged by aphids. When peonies sprout in spring, aphids fly over and suck the sap from the leaves, causing the affected leaves to curl and turn yellow. When the seedlings grow up, aphids often gather on the tender shoots, pedicels, and backs of leaves, causing the stems and leaves of the seedlings to curl and shrink, and even causing the entire plant to wither and die.

　　(2) Occurrence pattern: Aphids reproduce quickly and cause serious damage under high temperature and dry conditions. Aphids can reproduce several generations or even 20 to 30 generations a year. Aphids secrete nectar, which can hinder the physiological activities of the stems and leaves of the affected plants. At the same time, their nectar is a good culture medium for pathogens, often causing sooty mold disease, etc. Aphids can also spread viral diseases.

　　(3) Prevention and control methods

　　①Remove overwintering weeds.

　　② Protect and utilize natural enemies, the main natural enemies include Harmonia axyridis, Coccinella septempunctata, Coccinella lutea, Tortoiseshell ladybird, aphid fly and lacewings.

　　③ Spray 1000-1500 times diluted 40% dimethoate emulsion, or 1500-2000 times diluted 80% dichlorvos, or 1000-1500 times diluted 50% aphidicide emulsion.

　　Peony

There are about 35 species of Paeonia, distributed in the temperate zones of Europe and Asia. They are divided into two groups according to their growth habits and flower disc shapes. The first is the peony group, which is a deciduous shrub or subshrub with a cup-shaped or disc-shaped flower disc, leathery or fleshy, completely covering the carpel or covering the base of the carpel. There are three species (excluding variants), namely peony, yellow peony and purple peony. The second is the peony group, which is a perennial herb with an undeveloped flower disc that covers the base of the carpel and is not very obvious. There are about 30 species of Paeonia group plants, mainly distributed in the temperate zones of Europe and Asia. There are two other species produced in America, and some people list them as a separate group, called the American peony group.

　　Peony plants produced abroad are all important species of flowers, among which the most important four are: fern-leaf peony, with blood-red flowers, native to Bulgaria and the Caucasus; yellow peony, with light yellow flowers, or light green to white, native to the area between the Black Sea and the Caspian Sea; yellow peony, with yellow flowers, native to the area between the Black Sea and the Caspian Sea; red peony, with white to dark red flowers, native to southern Europe.

　　There are eight species and six varieties of peony plants produced in the country, among which the one commonly called peony is the main original species of the modern peony variety group. The eight species of peony are: grass peony, beautiful peony, peony, multi-flowered peony, white peony, Sichuan red peony, Xinjiang peony and narrow-leaved peony.

　　Flower type classification characteristics of peony

　　1. Single flower type: the flower is composed of a single flower

　　1.1 Melaleuca subtype: The petals increase naturally towards the centripetal, are arranged neatly, are similar in shape, and gradually become smaller from the outside to the inside; the stamens are only attached to the ovary, and decrease accordingly as the number of petals increases until they disappear. The flower shape is flat.

　　① Single-petal type: 2-3 rounds of broad petals, with normally developed stamens and pistils, usually refers to the original species type.

　　② Lotus type: 4-5 whorls of broad petals of similar shape and size; normal stamens or individual stamen petals transformed into broken petals, lanceolate petals or whisker-like petals scattered among the stamen group; normal pistils.

　　③ Chrysanthemum type: more than 6 petals, gradually getting smaller from the outside to the inside, normal stamens, fewer in number; normal pistils, more in number or

　　reduce.

　　④ Rose type: The number of petals increases greatly, gradually decreasing from the outside to the inside, and all stamens disappear; the pistils are normal, degenerate and become smaller, or disappear completely.

　　1.2 Subclass of the genus Louzi: The outer petals are wide and in 2-3 whorls; the stamens are centrifugally petalized, and the pistils are normal, petalized or degenerate. The flowers are raised or towering (except for the golden stamen type).

　　① Golden stamen type: The outer petals are wide, 2-3 rounds, the stamens and anthers are enlarged, the filaments become thicker, and the stamens are bright golden yellow; the pistils are normal.

　　② Tugui type: The outer petals are broad, 2-3 whorls, the stamens are completely transformed into whisker-like petals, needle-like petals or lanceolate petals, slightly larger from the outside to the inside, standing upright inside the outer petals; the pistils are normal or transformed into tongue-shaped petals, the color of the tongue-shaped petals or the color of the petal tips are often the original color of the stigma.

　　③ Golden ring type: The outer petals are wide, 2-3 rounds, and most of the stamens are petalized. The petals are tall, but a circle of normal stamens remains between the petals and the outer petals; the pistils are normal or petalized.

　　④ Crown type: The outer petals are broad and flat, in 2-3 whorls, with a small number of whisker-like petals, needle-like petals, lanceolate petals or broken petals growing in a ring close to the outer petals. Above them are tongue-like petals or lanceolate petals transformed from stamen petals, which are upright, raised, clustered inside the outer petals, with a small number of stamens in the center, or degenerated into a short state; the pistil is normal or petalized or degenerated.

　　⑤ Hydrangea type: Most of the stamens are transformed into tongue-shaped petals, similar to the secondary outer petals. When in full bloom, the whole flower is plump and shaped like a hydrangea. The central stamens are very few or degenerate; the pistil becomes smaller or degenerate.

　　2. Terraces: refers to the phenomenon that when a plant blooms, the center of the flower (or inflorescence) or the growth point between the flowers will differentiate into flower buds and bloom again. Another flower (upper flower) will form in the center of the flower (lower flower), and the upper flower will overlap with the lower flower, thus increasing the degree of double petals. Some varieties are even composed of 3 or even 4 flowers overlapping.

　　2.1 Melaleuca subtype: The single flower at the base (lower flower) has the basic characteristics of the single-flower Melaleuca subtype. Melaleuca terrace type (primary terrace type): The pistil of the lower flower is normal or slightly petalized; the pistil and stamen of the upper flower are generally normal. The whole flower is relatively flat.

　　2.2 Subclass of Louzi: The lower flower has 2-3 whorls of petals, stamens are petalized, pistils are petalized or degenerate. The whole flower is tall.

　　① Colorful petal platform type: the pistils of the lower flowers are petalized, and the stamens are multi-petalized; the stamens and pistils of the upper flowers are normal or slightly petalized.

　　② Layered terrace type: The pistil of the lower flower changes into a petal that is the same as a normal petal, and the stamen changes into a petal that is shorter than a normal petal; the stamen of the upper flower also changes into a short petal, and the pistil changes into a petal or degenerates. The whole flower has a distinct layered structure.

　　③ Ball-shaped flower: The stamens of the lower flower become petals, elongated and widened, and are no different from normal petals, and the pistils become petals and also become normal petals; the stamens of the upper flower become petals and are often difficult to distinguish from normal petals, and the pistils become petalized or degenerate. The whole flower is ball-shaped.

　　Peony is not only a famous flower, but also has roots for medicinal purposes. The roots are fresh, crisp and juicy, and are used as medicine. Red peony and white peony are processed differently. According to analysis, peony roots contain paeoniflorin and benzoic acid, and their uses vary from species to species. White peony in traditional Chinese medicine mainly refers to the root of peony, which is an antispasmodic, analgesic and menstrual medicine. It is effective for women's abdominal pain, stomach cramps, dizziness, gout, diuresis and other diseases. Generally, the roots of cultivated peony are used as white peony, because their roots are large and straight, and the quality of the processed finished products is good. Wild peony is sold only as red peony because of its thin roots. The red peony in traditional Chinese medicine is the root of grass peony, which has the effects of dispersing blood stasis, promoting blood circulation, relieving pain, and purging liver fire. It is mainly used to treat irregular menstruation, phlegm stagnation and abdominal pain, joint swelling and pain, chest pain, rib pain and other symptoms.

　　There are hundreds of ancient prescriptions that use white peony as the main drug, such as "Guizhi Decoction" uses peony to nourish the skin and the body's defense system; "Huangqin Decoction" uses peony to nourish the qi in the abdomen; "Zhi Gancao Decoction" uses peony to nourish the blood and the yin fluid. In the clinical practice of obstetrics and gynecology, peony is widely used. For example:

　　Peonies are large and gorgeous, with rich varieties. They are often planted in large areas in gardens. When they bloom, they are very spectacular. They are the main flowers in modern parks or flower beds. They are planted in strips along paths and roadsides, or cultivated at the edge of woodlands, and are matched with dwarf and creeping flowers. Sometimes single plants or two or three plants are planted to appreciate their special varieties and colors. There are also special gardens called peony gardens that are completely composed of peonies. Peonies are also important cut flowers, or inserted in vases, or used as flower baskets. If the buds are cut when they are about to bloom and placed in a cold cellar, they can be stored for several months. The main cut flowers are double-petal varieties; single-petal vases will fall and wither in a few days. The ancients commented on flowers: Peony is first, peony is second, and peony boasts that peony is the king of flowers and peony is the flower phase. Because it blooms later, it is also called "Palace Spring".

　　The seeds of peony can be pressed to make oil for soap making and mixed with paint for coating. The roots and leaves are rich in tannins, which can be used to extract tannins and can also be used as local pesticides to kill soybean aphids and prevent wheat stalk rust.

　　The main flower stories include the four phases of wearing flowers in their hair.

　　The main places for viewing peony are: Bozhou (the largest Chinese herbal medicine trading market in China), Yangzhou. In addition, there are: Heze (Caozhou Hundred Flowers Garden), Luoyang (National Peony Garden), and Beijing (Jingshan Park).

　　1.Peony is a perennial tuberous herb; tree peony is a deciduous shrub and a woody plant.

　　2. Peony leaves are narrower, with dark green on both sides; Peony leaves are wider, with green and slightly yellow on the front.

　　3. Peony flowers are mostly grown at the top of branches. The smaller buds grown in the leaf axils generally cannot bloom normally, but a few rare varieties can bloom, with a flower diameter of about 10-30 cm; peony flowers are grown at the top of the branches, mostly solitary, with a flower diameter of about 15-30 cm; 4. Different flowering periods: Peonies generally bloom in mid-to-late April, while peonies bloom in early to mid-May, with a difference of about 15 days in their flowering periods.