Basic introduction

Scientific name: poinsettia

English name: Poinsettia

Family and Genus: Euphorbiaceae Euphorbia.

Alias introduction

Ivory, pepper, Christmas flowers, poinsettia, poinsettia.

Distribution of origin

Tasco, originally from Mexico, was used as a pigment and medicine by the Aztecs (a branch of American Indians) long before it was introduced to Europe. 1825 by Joel, the first American ambassador to Mexico? Poinsettia was introduced to America. Guangdong, Guangxi and Yunnan provinces all have open cultivation, and the plants can be as high as 2 meters.

The origin of the name

Robert? RobertBuist gave this plant a scientific name, which is now "Poinsettia". At the same time, "Poinsettia", which evolved from the surname of Poinsettia, has been used as the English name of Poinsettia ever since.

morphological character

Evergreen shrub, 50 ~ 300 cm high, with white milk on its stems and leaves. The stems are smooth, the shoots are green and the old branches are dark brown. Simple leaves alternate, elliptic, entire or undulate-lobed, sometimes violin-shaped, and the top leaves are narrowly lanceolate; The leaves are hairy, thin and have obvious veins; The leaves near the inflorescence at the top are bract-shaped, and the plants are red when flowering, which is the main ornamental part. The cups are arranged in an umbrella shape and are terminal; The involucre is light green, with teeth on the edge, 1 ~ 2 rhubarb glands; Male flowers stipitate, without perianth; Female flowers are solitary and located in the center of involucre; The natural flowering period is 65438+February to the following February. There are white and pink varieties. I like warmth, humidity and plenty of light. Not tolerant to low temperature, it is a typical short-day plant. Direct strong light and insufficient illumination are unfavorable to its growth. Avoid stagnant water and keep the basin soil moist. Short-day treatment can advance flowering. Poinsettia likes humid and sunny environment, with strong phototropism and low requirements for soil, but sandy loam with slightly acidic fertility, humidity and good drainage is the best. The cold tolerance is weak, so the greenhouse cultivation in East China and North China must be moved into the greenhouse before frost, otherwise the temperature will be low and the leaves will be yellow and deciduous. The room temperature in winter should not be lower than 5℃, but 16- 18℃. Strict requirements for water, too wet soil, easy to cause root rot, fallen leaves and so on. Poinsettia leaves easily. Too high temperature, too wet soil or too strong or too weak light will cause leaves to fall.

biological property

I like a warm, humid and sunny environment.

The optimum growth temperature of poinsettia is 18 ~ 25℃, April ~ September and September ~ April 13 ~ 16℃. In winter, the temperature is not lower than 10℃, otherwise the bracts turn blue, the basal leaves turn yellow and fall off, and the phenomenon of "falling feet" appears. When the temperature rises in spring, branches can continue to sprout from the stems.

Poinsettia is sensitive to water. As long as the water supply is sufficient during the growth period, the stems and leaves grow rapidly, and sometimes the internodes lengthen and the leaves narrow. On the contrary, the lack of water in the basin soil or the alternation of dry and wet will cause the leaves to fall off. Therefore, the control of water is directly related to the growth and development of poinsettia.

Poinsettia is a short-day plant. The growth period of stems and leaves needs sufficient sunshine to promote the rapid growth of stems and leaves. In order to make the bracts turn red in advance, the sunlight care should be controlled within 12 hours to promote flower bud differentiation. If it is illuminated for 9 hours every day, the bracts will turn red after 5 weeks.

The soil is loose and fertile with good drainage. Potted soil is a mixture of cultivated soil, humus soil and sand.

Common varieties

A common variety is Ecke“s white "with milky white bracts. Rosette with pink bracts. Yipin yellow (Lutea), bracts pale yellow. Crimson poinsettia has crimson bracts. Triploid poinsettia (eckespointc- 1) has leaflike bracts and is bright red. Double poinsettia, gray-green leaves, red bracts, double. HenriettaEcke has bright red bracts and double petals. The outer bracts are flat and the inner bracts are erect, which is very beautiful. The bracts of spherical poinsettia ("Slamingsphere") are blood-red, double petals, and the bracts are curled up and down into a ball, which grows slowly. The leaves of mottled poinsettia are grayish green with white stripes and bright red bracts. Mrs. Pollack, with broad leaves, leaflike leaves and blood-red bracts. The new varieties listed in recent years are festive, short, with large bracts and bright red. Red, bracts wide, crimson. It worked. The leaves are like buildings, and the bracts are red. The orange-red bracts are very large. Pearls with yellow and white bracts. Pichacho is a dwarf species with dark green leaves and crimson bracts, which does not need hormone treatment.

Present situation of commercial production

At present, Paul Ecke of America, Fischer and Dümmen of Germany are the three largest poinsettia breeding companies and seedling suppliers in the world, among which Paul Ecke of America is the oldest and largest poinsettia breeding company in the world. Paul Ike's varieties are widely planted in any country in the world. In the United States, the annual output of poinsettia is about1200,000 pots, and 75% of the varieties come from Paul Ike Company. In Europe, the output of poinsettia is about1200,000 pots per year, and 40% of the varieties come from Paul Ike. In Asia, the annual output of poinsettia is about 20 million pots, and Paul Ike's varieties account for about 80%. At present, the varieties used in commercial production mainly include Freedom Series (Freedom? Family freedom? Red, free? Pink, free? Early red; Enduring series? Enduring in the family? Red, enduring? Pink, lasting? White, enduring? Marble; Peter in the Peter series? Marble, Petra? Pink, Peter star? Red, Peter Starr? White; Winter rose series (winter rose? Winter roses in the family? Dark red, winter rose? Morning marble, winter rose? Morning powder, etc. In addition to the prestige of major domestic varieties? (Eckadire), velvet red velvet? (Elkada), Millennium Perfi? Early Millennium, etc.

Daily maintenance

Poinsettia, also known as Christmas flower and old pepper, is a color-changing foliage plant native to Central Africa. Its flowers are so small that they are not easily noticed. What is striking is that the leaves at the top of plants will turn dazzling red after winter. The flowering period lasts from1February to February of the following year, and coincides with Christmas, New Year's Day and Spring Festival, which is very suitable for the festive atmosphere of the festival.

Poinsettia likes warm, humid and ventilated environment and can't stand low temperature. Too much sunlight and insufficient light are also not conducive to growth. During the growing period, fertilizer and water management and top-level maintenance should be done well.

When watering, we should pay attention to prevent it from being too dry and wet, otherwise it will cause the leaves at the lower part of the plant to yellow and fall off, and the branches will grow unevenly. When the weather is hot in summer, we should increase the watering amount appropriately, but don't accumulate water in the basin to avoid causing root rot. Other seasons depend on the dry and wet conditions of the soil in the basin.

Poinsettia is not strict with soil, but generally fertile sand is fine. When changing pots, decomposed organic fertilizer should be added as base fertilizer in time, and liquid fertilizer should be applied every half month during the growth and flowering period. After autumn, some fertilizers rich in potassium and phosphorus can be added to promote flower bud differentiation and ensure bright red and pure bracts.

Poinsettia grows rapidly after entering the growth period. At this time, we must pay attention to picking the heart and fixing the head, otherwise the branches will grow too high, which will not only affect the appearance and shape, but also reduce the ornamental value.

The propagation of poinsettia can be carried out by cutting. In spring and summer, cut a branch and apply some plant ash to the wound to prevent it from rotting. It can take root after being inserted into the soil for about 25 days.

In addition, the juice of poinsettia is poisonous, so don't touch it when pinching and cutting, so as not to cause skin discomfort.

Breeding and cultivation

The propagation of poinsettia is mainly cutting. Both old and young branches can be used for cutting, but it is difficult to survive if the branches are too tender. Generally, robust annual branches are selected in February and March, and cuttings with a length of 8- 12 cm are cut. In order to avoid the outflow of milk, the cuttings were immediately immersed in water or plant ash after cutting. After the cuttings are slightly dry, they can be inserted into well-drained soil or coarse sand, leaving 2-3 buds on the soil surface, keeping them moist and slightly shaded. It can take root at the temperature of 18-25℃ for 2-3 weeks, and then it can be planted or transplanted into a pot for about two weeks. After the seedlings are put into the pot, they should be given enough water and placed in a semi-cool place for about a week, then moved to a place where the sun can be seen in the morning and evening for about half a month, and then placed in a sunny place for maintenance.

Cultivation steps

Poinsettia, Euphorbia deciduous erect shrub. Simple leaves alternate, elliptic to broadly lanceolate, 10 to 15 cm long, hairy on the back, and narrow leaves (also known as bracts) are inserted at the top of branches. Poinsettia is native to Central America and potted in northern China. Flowering period is 65438+February to February of the following year.

First, the feeding method

Poinsettia is usually cut in clay pots or sinks, and both tender branches and dormant branches can be used. Cutting should be carried out after flowering in early spring, using dormant branches, each cutting 10 cm. Air-dry for 2-3 days aft cutting, or fully air-dry milk stained with soot at that cutting mouth, and plant the milk in plain sandy soil, wherein the depth is one third of the cutting length, and the spacing is about 5cm. After sowing, water it, place it in a ventilated and semi-cool place, keep the temperature at 15-20℃, and keep the pot soil dry and wet. New roots can be born in about a month. When the new shoots grow to 10 cm, they can be planted in small flowerpots.

Second, the preparation of culture soil

Poinsettia likes loose and well-drained soil. Generally, 3 parts of vegetable garden soil, 3 parts of humus soil, 3 parts of humus soil, decomposed cake fertilizer 1 part, and a small amount of slag are used together.

Third, temperature.

Poinsettia prefers warm to cold. When entering the room in the middle and late September every year, it is necessary to strengthen ventilation to make plants gradually adapt to the indoor environment, and the room temperature should be kept at 15℃ to 20℃ in winter. At this time, it is in the stage of bract discoloration and flower bud differentiation. If the room temperature is lower than 15℃, flowers and leaves will be stunted. In mid-June, it will be in full bloom after 5438+February, and it should be ventilated gradually.

Fourth, light.

Poinsettia likes sunshine and strong phototropism, belonging to short-day plants. Adequate light should be obtained all the year round, and the discoloration of bracts, flower bud differentiation and flowering period are more important. If the light is insufficient, the branches are easy to grow white, easy to get sick and dim in color. If they are kept in the shade for a long time, they won't bloom and fall leaves in winter. In order to advance or delay flowering, light can be controlled. Generally, the light is 8 to 9 hours a day, and flowering can last for 40 days.

Verb (abbreviation for verb) fertilization

Poinsettia likes fertile sand. In addition to adding organic fertilizer and horseshoe slices as base fertilizer when releasing and changing pots, in the growing and flowering season, apply 5 times diluted and fully decomposed sesame paste liquid fertilizer every 10 ~ 15 days. After autumn, you can also apply/kloc-0 0.3% compound fertilizer once a week for 3 ~ 4 times in a row to promote the discoloration of bracts and flower bud differentiation.

Six, watering

Poinsettia is not resistant to drought and humidity, so watering should be flexibly controlled according to the weather, soil and plant growth. Generally, water should be used to keep the soil moist without water accumulation, but water should be reduced after flowering.

Seven, plastic pruning

Before and after Tomb-Sweeping Day, the dormant old plants were changed into pots, old roots and weak branches were cut off, and new techniques were popularized to germinate. In the process of growing up, you need to pick your heart twice. The first time is in late June and the second time is in mid-August. Large amount of fertilizer and water should be controlled in cultivation, especially before the plant is finalized in autumn. When the branches grow to 20 to 30 centimeters, they will be shaped and bent. The purpose is to make the plants short, the flower heads neat and evenly distributed, and improve the ornamental value.

Cultivation and maintenance

Potted poinsettia can be mixed with 2 parts of garden soil, 2 parts of humus soil and compost 1 part. It likes light and must be placed in a sunny place, but it is best to move to a slightly shady place in summer. During the growing period, the soil should be fully watered to keep it moist all the time, and it should not be too wet. If the soil is too wet, it will often cause root rot; If the soil moisture is insufficient, it will lead to defoliation, so pay attention to watering evenly. When watering flowers, reduce the amount of water. If you water it too much, it will cause leaves to fall. The peak season needs a lot of nutrients, and liquid fertilizer is applied once a week from April to September. Topdressing should be light and thick fertilizer should be avoided. After the bud appears, phosphorus and potassium fertilizer should be applied near flowering to promote the growth of bracts and bright colors. After flowering, lowering the temperature to about 12- 15℃ can prolong the flowering period.

Poinsettia plants grow faster and need pruning and shaping. Generally, 3-5 knots are left at the base, and the rest are cut off to promote its branching; When the branch length is 15cm, it can be trimmed again. Trim until the end of early autumn, and then you can carry out plastic and bending modeling. Generally, branches begin to bend around 18 cm. Don't water the branches two days before each bending, so that the branches wilt slightly, so that they are not easy to break. The operation time is from 10 am to 4 pm, because the branches are soft and easy to bend during this time. When holding a bend, use a string to pull the branches into an arch and fix them. It can bend in different directions every once in a while, and the branches can be twisted and tied into a spiral to hover left and right, making plants shorter. The last bend should be about 20 days before flowering. When taking a curved shape, pay attention to the strong branches around, the weak branches in the middle, and the strong branches bend downward to a greater extent. At the same time, it is necessary to prevent the branches from breaking to avoid "dead bending". Through bending modeling, the branches and leaves of the plant can be evenly distributed, the height is consistent, the flowers are neat, and the whole plant is plump and beautiful. In addition, the purpose of shortening internodes and dwarfing plant types can be achieved by foliar treatment or soil irrigation.

Poinsettia is a short-day plant with a natural flowering period of 65438+February. If you want it to blossom ahead of time, you can treat it with short sunshine. Generally, the sunshine is maintained for 9 hours every day, and the single-petaled stuttering variety can bloom after 45-55 days of shading. If it is the National Day flowering, it must be shaded regularly at the beginning of August, and the amount of fertilizer, especially phosphate fertilizer, must be appropriately increased during the treatment period, so that big leaves can be produced.

Poinsettia bracts are brightly colored and have a long flowering period, which generally lasts for 3-4 months, and the flowering period coincides with Christmas and New Year's Day. Therefore, it can be planted in gardens, which is most suitable for potted plants and can be used as greening and decorative materials for balconies, living rooms, conference rooms and other places.

control of insect

Poinsettia is prone to gray mold, root rot, stem rot, leaf spot and other diseases and pests in greenhouse cultivation, and there are many targeted studies at home and abroad.

Gray mold mainly occurs in winter, which is the season when poinsettia blooms. Once it is rainy, wet and sunless, it often gets out of hand, which can harm poinsettia inflorescences, bracts, leaves and branches. Generally, water spots appear from tidbits. After that, the lesion was covered with a layer of pathogen meristem robe, and the pathogen continued to spread to the bracts. At the beginning, the bracts faded in water, and then gradually expanded into irregular shapes, and the bacteria spread to the branches, producing yellowish brown to brown spots on the branches. In the later stage, the spots obviously sag downward and become dark brown. In severe cases, the spots are dry and completely lose their ornamental value. The pathogen is botrytis cinerea, which is almost all over the greenhouse. It can feed on dead plant tissues or other organic substances and has a wide range of parasites. It can survive at the temperature of 0 ~ 38℃, as long as there is water. If the greenhouse is too humid, cold and light is insufficient, after 1 ~ 2 days, pathogenic bacteria will produce a large number of robes and begin to infect plant tissues.

Root rot and stem rot can infect adult plants, but also in seedbed stage, causing serious losses. Generally, it is more serious in high temperature season, and it is also easy to happen when the water content of cultivated soil is high. In the early days, plants withered. At this time, if you check the stem base, you can see that it is light brown, but the infected plants are not rotten or hydrolyzed. Later, the lesion gradually spread upward, and the wilting phenomenon became more and more serious. The diseased spot on the stem was slightly concave and yellow-brown, and the diseased spot tissue disintegrated in the later stage, which caused the plant to wither and die due to serious water shortage. Sometimes, the whole plant turns yellow in water and eventually rots and dies. White hyphae are seen near the ground, which is more serious. When the root is sick, it often causes root rot, which affects the normal growth of plants in the early stage and leads to death in severe cases. The main pathogens are Phytophthora, Rhizoctonia and Pythium. Rooted cuttings are most vulnerable to Rhizoctonia solani when put into pots, especially when stems are injured or chemical fertilizers are used! When salt accumulates on the surface of the medium; Pythium appeared when Euphorbia pulcherrima grew into a plant, which may have invaded during cutting and deteriorated when the environment was suitable for reproduction, leading to root rot and death. High temperature and excessive irrigation (unfavorable conditions) will cause late blight.

Leaf spot mainly occurs in spring and summer, and the disease spots mostly start from old leaves. In the early stage, purple-red to brown spots were produced on the leaves, and the lesions were nearly round to irregular. Later, the lesions gradually expanded, and most of the lesions could heal with each other to form large lesions, and the center of the lesions gradually turned grayish brown in the later stage. In severe cases, the diseased tissue will gangrene, resulting in twisted and dry leaves. The pathogen is Cercospora puleherimaether p., which spreads through rain and wind, and invades through leaf margins or wounds.

The pests of poinsettia mainly include whitefly, spider mite, thrips and so on. Adults and larvae of Bemisia tabaci like dense and cool environment. They cluster on the back of the upper leaves of Poinsettia and suck juice with stinging mouthparts, which makes the leaves fade or appear chlorosis spots, which affects photosynthesis and leads to poor plant growth. Honey dew discharged by insects often causes mildew. Adults have a tendency to turn yellow. The eclosion time starts at 6: 00 in the morning, with the highest eclosion at 7-8: 00 and the lowest at night. The first instar larvae are the most vulnerable, followed by newly emerged adults, which are sensitive to chemicals and suitable for spray control. Whitefly usually occurs in large numbers under the conditions of high temperature and low humidity, and the peak period is from late September to late October of 165438+ 10. The best control period is in late September and the application time is 6 ~ 10 in the morning.

Tetranychus urticae, also known as red spider, is a common pest in greenhouse. There are more than 20 generations in the whole year, which is serious under the conditions of high temperature, drought and little rain, and the peak periods are March-June and September-165438+1October. Mites or nymphs like to live on the back of old leaves, and the damaged leaves have yellow spots. Insects, eggs, silk screens and secretions can be found by examining the back of leaves. A large number of netting hazards occur, which leads to plant growth stagnation, dry leaves, falling off and plant death.

The body length of thrips is only about 1 ~ 2 mm, and its harm can be found on the leaves or flowers of almost all greenhouse plants. But overall, the damage to poinsettia is not very serious. Adults and nymphs are pale yellow or orange, which is harmful to plants with file suction mouthparts. The damaged parts include buds, leaves and flowers. Especially, the young leaves and shoots are the most seriously damaged, which leads to poor plant development. The white markings on both sides of the main veins of leaves can be judged as the damage characteristics of thrips. The damaged leaves cause white or brown markings, and in severe cases, the leaves are twisted and deformed. Flowers are deformed. Yellow armyworm paper is effective for thrips adults, but blue and white armyworm paper is more effective.

The key to control whitefly is to avoid a large population. Adult whiteflies are attracted by bright yellow, so yellow sticky trapping paper is very useful in detection. There are many drugs to control whitefly in various places, such as "Pujiaoling" and "Efficient Hero", which can be tried. It should be noted here that before a new drug is used in a large area, a toxicity test must be done to confirm that the dosage used will not cause toxicity to plants before it is used in a large area.

Postpartum treatment

The coming winter festival coincides with the unique and delicate red bracts of poinsettia. Decorate the indoor environment of public places with potted plants or hanging pots, and suddenly the room is full of brightness, showing a warm and happy atmosphere. A few pots adorn the windowsill, balcony or study, red and green, charming and moving. Poinsettia is sensitive to cold and hot wind during storage and transportation, and ethylene will wilt the plant, so silver thiosulfate solution (concentration 0.3 ~ 0.8 mmol) should be sprayed. At the same time, during storage and transportation, the bracts and leaves of poinsettia bend upward, which is mainly caused by the internal accumulation of ethylene. Under the condition of 10℃, the storage and transportation of the package shall not exceed 48 hours until the package is opened. Freezing injury will occur when the temperature is lower than 10℃, and the petiole will bend upward and the bracts will fall off when the temperature is higher than 10℃.

Debate about toxicity

Some people think that the whole plant of Poinsettia is poisonous, and the white juice in the stems and leaves will irritate the skin, which may make the skin red and swollen and cause allergic reactions. If you eat stems and leaves by mistake, it will cause vomiting, abdominal pain, and even the danger of poisoning death.

There are also rumors that toxicity has no scientific basis. As early as 197 1, Ohio State University made a special study on the toxicity of poinsettia. It was found that there was no abnormality in diet and daily behavior, and there were no symptoms such as death and poisoning. The poison index of the United States provides the research results of a toxic substance information center, and the conclusion is that a child weighing 50 kilograms will not be poisoned if he ingests 500-600 poinsettia leaves. 1990, Klug conducted a telephone interview, and the results showed that very few people had skin discomfort reaction to the white juice of poinsettia. Among the 353 people interviewed, 0.02% have red skin and 0.0028% have a runny nose. In addition, according to the investigation of the American Medical Association, no death or serious injury cases were found after eating poinsettia. In short, it turns out that poinsettia is not as toxic as some media say, and like other flowers, poinsettia is for people to watch rather than eat! Therefore, when buying or maintaining poinsettia, you can completely eliminate worries and enjoy the happiness and joy brought by poinsettia.

Value use

Poinsettia is cool and bitter, and has the functions of regulating menstruation, stopping bleeding, promoting blood circulation, resolving phlegm, setting bones and reducing swelling.

Choosing the right amount of poinsettia can treat the following diseases:

1, functional uterine bleeding: 20g of poinsettia, decocted in water, or 0g of poinsettia10g of Ai Chen charcoal10g of Eclipta prostrata, decocted in water.

2, bruises and swelling: Poinsettia fresh leaves in moderation, mashed and applied externally.

Poinsettia is brightly colored and has a long flowering period, which coincides with Christmas, New Year's Day and Spring Festival. Potted indoor environment can increase the festive atmosphere and is very popular with people. It is also suitable for arranging public places such as meetings. The southern warm land can be cultivated in the open field to beautify the garden, and can also be used as cut flowers.

Main points of purchase

1. Count flower heads: each branch is called a flower head. Generally, flowers with less than 6 heads are inferior, flowers with 6 to 8 heads are medium, and flowers with more than 8 heads are superior.

2. The flower heads are flush: the ideal poinsettia should be that the flower heads are uniform in size, evenly distributed on a sphere, and densely clustered together, and the ratio of crown height is greater than 1.0, preferably greater than 1.3. This finished flower looks generous and stretched.

3. Look at the foot leaves: hold up the poinsettia and look at its foot leaves from the side. If many leaves turn yellow and fall off, they belong to low-quality potted flowers. Whether the branches are strong or not is also an important criterion to judge the quality of poinsettia. Branches are too long and internodes are too long. Viewed from the side, the branches are completely exposed, which is also defective.

4. Look at the flowers: Poinsettia is beautiful, but what makes you happy is not its flowers, but its bracts. But looking at the real flowers at the top helps to judge the quality of poinsettia. If most of the small yellow flowers at the top are in full bloom, and there are more small flowers on the side buds, it is called "blooming". Most of this poinsettia has a short flowering period, so it is difficult to extend the storage time when it is bought home.

5. Hands-on: Gently fiddle with the corolla. If it collapses, the flowering period will not last long. The ideal poinsettia should be thick branches and leaves, giving people a feeling of vigorous progress.

Transport requirements

1. Temperature: The optimum temperature is 65438 02℃ to 65438 08℃. If it exceeds 18℃, it will aggravate the drooping of leaf bracts. If it is transported at 2℃ to 10℃ for a long time, it will cause chilling injury, including wilting, defoliation and blue color of bracts.

2. Moisture: Generally, it should be drenched the day before loading. Moderately moist soil for fashion bag packaging. 3. Fertilizer: Do not apply fertilizer before transportation to prevent root burns and leaf bracts from being damaged.