Key points of Chrysanthemum cultivation and Control techniques of Diseases and insect pests in South China

There are many varieties of chrysanthemum in China, and they are also cultivated in many areas. Chrysanthemum can also treat dizziness, headache, exogenous wind and heat, and so on. At present, the market price of chrysanthemum continues to be about 20 yuan per kilogram. Let's learn the breeding methods and pest control and cultivation techniques of chrysanthemum in southern China.

1. Land selection and preparation

Chrysanthemum does not have high requirements for planting soil, the sandy soil with good drainage, loose and high humus is better, clay and low-lying saline-alkali land is not suitable for planting, chrysanthemum can not be continuous cropping. With the application of ternary compound fertilizer 50~80kg per mu, organic fertilizer can be applied with 5000 kg, deep rotary ploughing twice and raking flat.

2Propagation and transplanting

When the chrysanthemum seedlings reached 15cm from April to May, the whole plant was dug up and divided into several plants. According to the plant spacing and row spacing 30cm × 55cm, the chrysanthemum seedlings were planted in the field. After planting, they were watered enough and irrigated again after half a month. At the same time, the field management should be strengthened in order to reduce the occurrence of diseases and insect pests. 2min can be sprayed or soaked with 300g carbendazim and 200x imidacloprid before planting, and watering combined with weeding can be irrigated with 150g / mu 300g trifluralin.

3. Field management

After the chrysanthemum turns green and survives, it is ploughed in time to prevent the cracks in the land from running into the wind, and then loosen the soil and weed according to the general management method until the bud appears. Generally in July to prevent the overgrowth of chrysanthemum with multi-nitrazole chemical control, should be watered once after budding, at the same time supplement trace element fertilizer, to lay a good foundation for flowering. Chrysanthemums avoid flooding and should be drained in time when Rain Water is too often.

(4) Disease and pest control

The common diseases of chrysanthemum include root rot, downy mildew, brown spot and so on. In particular, the disease will be more serious in Rain Water season. 430 g / L tebuconazole 2500 times and 80% carbendazim 800 times can be used for prevention and control. Insect pests are generally aphids, and red spiders occur in individual plots, which can be controlled by 300 times of 10% imidacloprid wettable powder, 500 times of 20% acetamiprid, and 1.8% of avermectin or spiromites 500 times.

5 harvest and drying

Chrysanthemums are generally harvested before and after Frosts Descent, and it is best to spread the flower heart. The whole medicinal plant is cut down and bundled into bundles, stacked into a stack of half an mu, keep it ventilated and dry, pick and dry the flowers in sunny weather, and the flowers are white and loose. Tea chrysanthemums should be buckled in time to prevent frost damage, timely picking, drying, according to the principle of how much to pick and how much to dry, so as not to affect the quality.

Generally speaking, chrysanthemum has the advantages of small investment, good management and high income, and the planting area is also increasing year by year. However, in order to achieve high yield, it is critical to obtain high-yield management techniques of chrysanthemum.

Technical points of field cultivation of chrysanthemum

Chrysanthemum is a perennial perennial herb. It likes sunny, cool, cold-free climate and dry and ventilated environment. It requires rich humus, rich and loose neutral soil, drought and weak alkali tolerance, and the suitable growth temperature is 15 ℃ to 25 ℃. Several key techniques should be mastered in planting cut chrysanthemum in the field.

The varieties of late autumn chrysanthemum and winter chrysanthemum which are not easy to suffer from freezing injury can be selected for the selection of late autumn chrysanthemum and winter chrysanthemum varieties, which have strong cold resistance, thick and stiff petals, stout and straight stems, uniform internodes, thick and flat leaves, suitable for long-distance transportation and storage, and can be tall and straight and rejuvenated after water absorption. it can open completely and for a long time after soaking. If the cut chrysanthemum is produced in northern China, if it wants to supply the market in May, it should be cut in October of the first year and cultured in the greenhouse in winter; if it wants to blossom from August to September, it can be raised in March of the same year and treated with short-day light 60 days earlier. It is relatively easy to supply cut chrysanthemum flowers in winter and early spring in the south, which does not need a greenhouse and can be planted in a large area, but high beds need to be made to prevent flooding. Proper shading at noon in the dry season can increase the length of the stem and facilitate vase.

The preparation of chrysanthemum before planting should avoid wet water. In order to cultivate cut chrysanthemum in the field, it is necessary to have a deep trench and a high border, with a height of 25 to 30 centimeters, a width of 1 to 1.2 meters, and a length of no more than 30 meters. A good waist ditch should be opened around the field, and the waist groove should have the function of storage and drainage, so that Rain Water does not leave the ditch and the rain stops without leaving water. Cut chrysanthemum grows vigorously and needs a large amount of fertilizer. the application of long-acting organic fertilizer can loosen the soil and promote the growth of plant roots. Continuous cropping of cut chrysanthemum is not suitable for continuous cropping with the same kind of crop.

Planting cut chrysanthemum can be divided into multiple plants and single plants, and export cut chrysanthemums planted in the field are generally cultivated in single plants. General single-plant cultivation of about 60 plants per square meter, each row of 4 rows, row spacing 25 cm, plant spacing 6 cm. When the chrysanthemum grows to 30 cm high, the plastic shallow net of 12 × 12 square cm is used to spread the net of the main plant so that the branches of the chrysanthemum are evenly distributed.

It is very important to manage the watering of cut chrysanthemum with fertilizer and water. in addition to increasing watering during flower bud development, it should be dry and wet less, dry and wet alternately, less furrow irrigation and immersion irrigation. Because of high planting density and high fertilizer consumption, cut chrysanthemum must be often combined with watering and topdressing in addition to applying base fertilizer. Generally, before budding, nitrogen and potash fertilizer are given priority to, and then phosphate fertilizer is applied appropriately. Topdressing should be applied frequently to prevent excessive fertilization. When the chrysanthemum plant turns to reproductive growth, fertilization can be suspended to facilitate flower bud differentiation. After budding, topdressing is carried out.

Pruning and pruning should be strong and weak, branches should be removed, and axillary buds should be erased in time, so as to reduce nutrient consumption and ensure that the plant reaches a certain height. After budding, all lateral buds below the main bud should be removed in time. In the process of cultivation, if there is a "willow leaf" phenomenon, we should pick the heart and change the head as soon as possible to let it pull out the new technology again.

The main diseases and insect pests of cut chrysanthemum are leaf spot and aphids. In the early stage of growth, fungicides should be used regularly to prevent the occurrence of all kinds of leaf spot, and when entering the reproductive stage, powdery mildew and aphids should be prevented from harming flower buds, so as not to affect the quality of cut flowers. The outbreak period of chrysanthemum leaf spot is very long, which continues from April to October, and Rain Water is the most serious when there are more before and after the Beginning of Autumn. Reduce the watering times as much as possible after the disease, spray Bordeaux solution or Dyson zinc 500 times solution, spray once every other week, stop spraying before the bud is clear. Aphids should be sprayed before the occurrence of fish rattan essence to prevent, after the disease should be sprayed two or three times, they can all be eliminated.

Late autumn chrysanthemum and winter chrysanthemum are typical short-day plants, and the length and intensity of light have influence on flowering and flower color. Light supplementation of chrysanthemum can inhibit flower bud differentiation. Generally 6 meters wide standard greenhouse can grow 4 rows, each of which hangs a row of 60 watts with an interval of 1.5 to 2 meters, with a height of 90 to 100 centimeters from the plant. Replenishing light is carried out from 23:00 to 2 o'clock every day, usually starting at the end of August, and the number of days should be determined according to the planting time.

Harvest and cold storage when the color of the bud is 30% to 50%, it is the right time to pick flowers. It is generally harvested in the early morning or evening, which is good for keeping fresh. The harvested chrysanthemums were immediately transported to the fresh-keeping factory for pre-cooling, and the temperature was controlled at about 10 ℃. After pre-cooling, the chrysanthemum is trimmed, generally retaining the stem length of about 90 cm, with 10 branches as a unit, sent to the freezer. Cold storage can be divided into wet storage and dry storage. Wet storage is generally used for short-term storage, the method is to insert the flower stem in the fresh-keeping solution, the formula of the fresh-keeping solution is to add 20 grams of sucrose, 25 milligrams of silver nitrate and 200 milliliters of 8-hydroxyquinoline citrate per liter of water; dry storage is to store cut chrysanthemum in plastic bags or cartons in cold storage. Be careful not to put it in a cold storage with fruits and vegetables, lest ethylene produced by fruits and vegetables affect the preservation of flowers. The cold storage needs to maintain 90% to 95% relative humidity, the temperature is controlled at 0 ℃ to 17 ℃, and can be stored for 3 to 4 weeks.

Introduction to planting and cultivation of Dahlia

Name: Dahlia

Dahlia nicknames: Dahlia, Tianzhu peony, peony, sweet potato flower, marble, passionflower, chrysanthemum

Scientific name: Dahlia pinnata Cav.

English name: Dahlia,Garden Dahlia

Family name: Compositae of Compositae, Dahlia

Flower language: Dahlia-auspicious French Flower language: Dahlia-grateful, fresh, novel, new

Dahlia is a perennial herb of Compositae. The chrysanthemum is in full bloom, but the dahlia is different. it blossoms one after another in spring and summer, blossoms again after summer, and withered when Frosts Descent. Its flower shape is similar to the peony of the country, the color is magnificent and colorful, lovable.

Dahlia is the national flower of Mexico, the city flower of Seattle, the provincial flower of Jilin Province, and the city flower of Zhangjiakou City, Hebei Province. The colorful Dahlia symbolizes generosity, richness and good fortune. Today, its footprint has spread all over the world, becoming a frequent visitor in the garden and a world-famous ornamental flower.

Dahlias are easy to reproduce, sowing, cutting and root splitting. They like sunshine and loose, fertile and well-drained soil. Grafting at the beginning of the bud can produce colorful marble and dahlia.

Dahlias are suitable for flower beds, flower paths or pre-court cluster planting, and dwarf varieties can be used as potted plants. Flowers are used to make cut flowers, baskets, garlands, etc. The root tuber contains inulin, which is similar to glucose in medicine. The whole plant can be used as medicine and has the effect of clearing away heat and detoxification.

Dahlia area

Dahlia's hometown is 1500 meters above sea level in the Mexican plateau, it is neither cold-resistant, but also afraid of heat, where the climate is warm and cool, there is a period of low temperature dormancy. Dahlia has a suitable climate and grows well in Liaoning and Jilin in China.

Dahlia has thick hammer-shaped fleshy roots, plant height varies with different varieties, leaves opposite, 1-3 pinnately divided, lobes ovate, serrated and obtuse. The flowers are longer than the top of the pedicel. Dahlias are popular for their long florescence, blooming continuously from autumn to spring, with each flower lasting for one month and lasting for half a year. In the south of our country, it is open from 2mi in spring to June.

Characteristics of Dahlia

Dahlia is also known as passionflower and dahlia. If you want to cultivate dahlias well, you need to master its four characteristics: (1) like wetting and afraid of waterlogging. Dahlias are afraid of drought and avoid stagnant water. This is because dahlias are fleshy roots, which are easy to rot if they are watered too much. But its leaves are large, grow luxuriantly, and need more water. If the lack of water and wilting can not replenish water in time, after sunlight, the edge of the light leaf will be scorched, and the heavy leaf will fall off. Therefore, watering should grasp the principle of "dry and thoroughly irrigated". (2) like to be fertile and afraid to be excessive. Planting dahlias should choose fertile and loose soil, in addition to applying basic fertilizer, but also topdressing. Usually from the middle to the end of July until flowering, thin liquid fertilizer is applied every 7-10 days, and the concentration of fertilization should be gradually increased to make the stem grow stronger and stronger, and the leaf color dark green and stretch. (3) like sunshine and fear shade. Dahlias like to be sunny. If placed in the shade for a long time, the growth is poor, the root system is weak, the leaf is thin and the stem is thin, the flower is small and light, and even cannot blossom. Only when it is planted in a sunny place, can the plant grow healthily and produce bright flowers. (4) like cool and afraid of heat. Dahlia blossoms like cool climate, the temperature is about 20 ℃, the growth is the best. Planting in North China and other places can grow well from late spring to late autumn. But it is afraid of the hot summer sun, especially the sunny exposure after the rain, at this time should be a little shade, the growth is better.

Propagation method of Dahlia

Root division and cutting propagation are the main methods, and seed propagation is used for breeding.

1. Split root propagation

This method is the most commonly used. Because dahlia can germinate only in the root neck, it must have part of the root neck when it is divided, otherwise it can not germinate new plants. In order to facilitate identification, the method of burying roots in advance is often used to accelerate budding, and then split and planted after the adventitious buds on the root neck germinate. The root-splitting method is simple and easy, the survival rate is high, the seedlings are strong, but the number of propagation plants is limited. 2. Cutting propagation is the main propagation method of Dahlia. The propagation coefficient is large, which is generally carried out in early spring, summer and autumn, and the survival rate of cutting in greenhouse or hotbed from March to April is the highest. The cuttings were taken from the tuberous roots which had been accelerated, and the cuttings could be peeled off from the base when a pair of leaves at the base of the new buds were unfolded. You can also leave more than one section at the base of the new buds, and then take the buds at the axillary buds with the growth, so that more cuttings can be obtained. The spring seedlings grow fully in summer and autumn and can blossom in the same year. Buds can be taken from growing plants for summer cutting from June to early August, but the survival rate is lower than that in spring. The survival rate of cuttings from September to October is lower than that in spring, but higher than that in summer. It is suitable to insert soil with sandy loam and a small amount of rotten leaf soil or peat.

3. Seed propagation is limited to flower bed varieties and breeding. The seeds are mostly collected from those who mature after autumn cool because of the poor fruiting in summer due to damp and hot. Vertical petal varieties are not easy to obtain seeds, so artificial pollination should be carried out. The sowing is generally carried out in the sowing box, about 20 C, sprouting and unearthing in 4-5 days, replanting after the true leaves grow, and flowering after 1-2 years.

Cultivation method

Dahlia stem crisp tender, can not withstand the strong wind attack, but also afraid of waterlogging, when planting to choose high dry terrain, good drainage, sunny and leeward place, and make a high bed. The plant row spacing is about 1 meter for general varieties and 40 cm ~ 50 cm for dwarf varieties. The stem of Dahlia is tall, juicy and tender, and a pillar should be set up to prevent the wind from breaking. Watering should grasp the principle of dry and re-watering, suddenly clear after continuous cloudy days in summer, spray clear water to the ground and leaves in time to cool down, otherwise the leaves will have scorched edges and withered yellow. When there is no rain in summer, in addition to watering every day, water should also be sprayed to cool down. After bud development, liquid fertilizer is applied every 10 days until the bud is clear. Leave 10 cm ~ 15 cm root neck before frost, cut off branches and leaves, dig up the root, hang it on the spot for 1 ~ 2 days, and then store it indoors with dry sand. The storage room temperature is about 5C.

It is better to change pots for potted dahlias. Choose a shallow basin with a large mouth, and chisel the drainage hole at the bottom of the basin as big as possible, with a layer of broken tiles underneath as a drainage layer. The cultivated soil must contain half of the sand. The last pot change requires the application of sufficient base fertilizer to provide adequate nutrition, and other management will be planted in the same place. Cut flowers with dahlia, the main points of cultivation are planted in the same ground, the plant row spacing is 50 cm ~ 100 cm, topdressing liquid fertilizer once in half a month in the peak growing season, properly coring, and keeping more lateral branches.

Cultivation and management

Multi-purpose cutting and sowing propagation, mainly cutting, generally carried out from September to October.

The pot time of ① is usually in the middle of October, with 1-2 plants per pot.

When the seedling grows 10-12 cm in height, ② leaves 2 nodes to peel off the top, culturing 6-8 branches in each pot, and the last coring is carried out 40-50 days before the Spring Festival, in order to control flowering during the Spring Festival.

③ watering: watering 2-3 times a day. Water can be properly controlled to promote flowering before flowering.

④ fertilization: nitrogen fertilizer was applied mainly in the early stage, and phosphorus and potassium fertilizer was applied in the later stage. Generally, inorganic fertilizer is applied once every 10 days and organic fertilizer is applied once a month.

⑤ pest control: regular spraying to protect foot leaves

⑥ binding bamboo: after the last heart is removed and branches are fixed, begin to bind bamboo, one piece of bamboo per branch, and remove too many side branches for ventilation

⑦ picking buds: when buds grow to the size of peanuts, 2 buds are left on each branch, and other buds are removed

⑧ buds: when buds are red, only one bud is left for each branch.

The key to the growth of potted dahlia lies in strengthening the management of plant pot soil, giving sufficient light, frequently applying water and fertilizer, timely shaping and pruning and so on. (1) the management of basin soil Dahlia is suitable for sandy loam which is loose, rich in humus and good drainage. Potted dahlia planting soil is generally suitable for vegetable garden soil (50%), rotten leaf soil (20%), sandy soil (20%) and dried dung (10%). The consolidated soil is easy to cause waterlogging and rotting roots, which can not be used. In the daily management, loosen the soil in time and eliminate waterlogging in the basin, because the fleshy root of Dahlia rotted when there was too much water content in the soil and poor air permeability.

(2) Lighting

Dahlia likes light and is not tolerant to shade. If it is placed in the shade for a long time, it will grow poorly, the root system is weak, the leaves are thin and the stems are thin, the flowers are small and light, and some even cannot blossom. Therefore, potted dahlias should be placed in a sunny place. There is sufficient light in the leaves, which requires more than 6 hours of light a day, so that the plants are strong and the flowers are large and plump. If the sunshine is less than 4 hours a day, the branching of stems and leaves and the formation of buds will be affected to a certain extent, especially if there is little sunshine, the flowering is not smooth, the growth of stems and leaves is poor, and it is easy to get sick.

(3) watering frequently

Dahlia like water but avoid stagnant water, both afraid of waterlogging and drought, this is because the big flower is fleshy root, too much watering root is easy to rot. However, Dahlia has luxuriant branches and leaves, large evaporation, and needs more water, if it can not replenish water in time after wilting due to lack of water, and then exposed to sunlight, the edge of the light leaf will be scorched, and the heavy basal leaf will fall off. Watering should grasp the principle of "dry and thoroughly irrigated". In general, water is limited in the early growth stage, and it can be watered once a day on a sunny day, keeping the soil slightly moist, and it is not appropriate to be too dry and wet. In the later stage of growth, the branches and leaves are luxuriant and consume more water. Sunny or northerly weather. Note that it is easy to lack water at noon or evening, and the amount of water should be increased appropriately.

(4) proper fertilization of dahlia is a kind of fertilizer-loving flower, which is usually applied with dilute liquid fertilizer every 10-15 days from seedlings. Apply it every 7-10 days after budding. Stop watering when the flower buds are transparent. It is not suitable to apply fertilizer when the temperature is high. The amount of fertilizer applied depends on the growth of the plant. Where the leaf color is light and barren, it is the phenomenon of lack of fertilizer; on the contrary, if the fertilizer is excessive, the leaf edge is scorched or the leaf tip is yellow, and the leaf is thick and dark green, which is the performance of proper fertilization. The concentration of fertilizer should be increased each time, so that the stalk can be sturdy.

(5) the pruning and pruning of potted dahlias should be controlled flexibly according to the varieties. In general, single-plant plastic surgery is used for large varieties and 4-book plastic surgery for medium-sized varieties. Single plant plastic surgery is to retain the terminal bud, remove all the bowels, so that nutrition is concentrated, forming a low plant, large flower type of single plant Dahlia. 4 this dahlia is a potted dahlia with 4 stems and 4 flowers, which is made by coring the seedling and keeping the two basal nodes to form 4 lateral branches, with terminal buds on each side.

(6) the stem of Dahlia is empty and brittle, and it is easy to be broken by the wind. Bamboo planting can also avoid the bending of branches and improve the ornamental value of potted plants. When the plant is more than 30 cm tall, a small bamboo should be inserted next to each branch and tied with hemp skin (or string); as the plant grows taller and taller, a longer bamboo should be replaced in time, and the final bamboo should be placed on the lower part of the bud. (7) to protect the safety of the plant overwintering Dahlia is not cold-resistant (mainly because the root can not be frozen). In November, when the branches and leaves withered, the aboveground part should be cut off, moved into the room, and preserved in the original pot. The root tuber can also be taken out and hung for 1-2 days and buried in indoor moist sand with a temperature of no more than 5 degrees, and then planted in the pot the following spring.

Prevention of diseases and insect pests in Dahlia

The diseases and insect pests that are easy to occur in the process of Dahlia cultivation are powdery mildew, flower rot, borer moth and red spider.

(1) Dahlia powdery mildew

The disease is serious from September to November, and high temperature and humidity will contribute to the occurrence of the disease. After being killed, the plant is short, the leaf surface is uneven or curly, and the tender shoot is malformed. Flower buds cannot blossom or can only produce deformed flowers after being killed. When the disease is serious, the leaves can dry up and even the whole plant will die.

Prevention and control methods:

① strengthens the maintenance to make the plant grow healthily and improve the disease resistance. Control watering and increase the application of phosphate fertilizer.

When ② occurs, the diseased leaves should be removed in time and sprayed with 50% Dysenamine aqueous solution or 70% topiramate solution.

(2) Dahlia flower rot.

Most of them occur from full bloom to falling bloom, when the soil moisture is on the high side and the ground temperature is on the high side, the disease is beneficial to the occurrence of the disease. When the petals are injured, the disease spot is faded green at first, then becomes yellowish brown, and the disease spot is irregular after expansion, from yellowish brown to grayish brown.

Prevention and cure method

Ventilation and light transmission should be strengthened among ① plants; in the later stage, water and nitrogen fertilizer should not be used too much, and phosphorus and potassium fertilizer should be increased.

After the bud stage of ②, 0.5% Bordeaux solution or 70% topiramate 1500 times solution can be sprayed once every 7-10 days, which has a good control effect.

(3) Spodoptera litura

The insect mainly harms dahlias and chrysanthemums by larvae drilling into the stem. When seriously damaged, the plant can not blossom, or even maimed.

Control methods: generally from June to September, spray 90% of trichlorfon 800 times every 20 days or so, which can kill newly hatched larvae.

(4) Red spider

Red spider is cinnabar spider mite, you can see the control section of cinnabar spider mite in Jasmine.

Dahlia is a perennial herbaceous flower of Compositae. Leaves opposite, 1-3-parted, margin serrate. Head terminal, purple, pink, pink, complex color and other colors. (5) insect pests of cotton leafhopper of Dahlia

Harm: adults and nymphs suck juice on the back of the plant leaves, resulting in yellowish-brown spots on the leaf surface, leaf wrinkling to the back, and severe discoloration and scorching of the whole leaf.

Prevention and control methods: A. Combined with pruning, cutting off the damaged branches and leaves and treatment, in order to reduce the source of insects. b. In the period when adults are harmful, light is used to trap and kill adults. c. During the nymph and adult occurrence period, 90% crystal trichlorfon 1000-1500 times, or 40% omethoate EC 1000-1500 times, or 2.5% deltamethrin EC 1500-2000 times, can be sprayed every 10 days or so.