How to prevent and cure downy mildew of Platycodon grandiflorum? Incidence regularity and control measures of downy mildew of Platycodon grandiflorum

The plant height of Platycodon grandiflorum is 30-100 cm. Leaves opposite, broadly elliptic to lanceolate, almost sessile, leaf base slightly clasping; leaf surface blue-green. Stamens and pistils obvious, bracts narrow-lanceolate, petals imbricate. Flowers and colors are rich, there are monochrome and complex color, petals single and double petals. However, Platycodon grandiflorum is often affected by downy mildew, and many flower friends ask me what to do. The following editor introduces the incidence regularity and prevention measures of Platycodon grandiflorum as follows.

I. incidence regularity of downy mildew of Platycodon grandiflorum

Downy mildew prefers cool but not too hot temperature. It is easy to occur at night temperature of 8 ℃ ~ 16 ℃, but it may occur below 20 ℃. The growth of downy mildew is most closely related to high humidity or water, especially when water film is accumulated on the surface of plant tissue for a long time. The formation of water film is related to the dew point, so it is possible to occur when the temperature is below the dew point temperature. The downy mildew of Platycodon grandiflorum is more likely to occur in cloudy days or continuous rainfall, so it should be prevented and controlled according to the weather forecast. According to the experience of Taiwan, downy mildew of Platycodon grandiflorum is easy to occur when the daily average temperature is lower than 17 ℃ and there is continuous rainfall for 3 days. According to foreign research, the incidence conditions of grape downy mildew in open field are that the rainfall in 24 hours is more than 10mm and the temperature is lower than 11 ℃. The conditions of oospore germination are that the temperature is more than 8 ℃ and the soil surface 1 ~ 2cm is moist for more than 16 hours. On the other hand, rose downy mildew can occur when the leaves are moist for more than 2 hours, and the incidence increases significantly after more than 10 hours. It can also occur when the temperature is as low as 5 ℃ and the leaves are moist for more than 8 hours.

II. Integrated control of downy mildew of Platycodon grandiflorum

1. Environment control

For downy mildew, almost all varieties of host Platycodon grandiflorum lack resistance, and the pathogens can be transmitted by water flow and air, and can hardly be isolated. The best control method is based on environmental control and disease prevention, supplemented with a small amount of protective fungicides. The small and medium-sized climate in the greenhouse changes very dramatically during the day. The regulation of temperature and humidity such as heating, ventilation and cooling is very important. In particular, heating at night to avoid low temperature, high temperature and leaf condensation are the key measures to control downy mildew of Platycodon grandiflorum.

two。 Horticultural control

The main measures are formula fertilization and reasonable irrigation. Remove susceptible leaves, diseased stems and diseased plants in time. Reasonable close planting, strengthen ventilation and light transmission, especially in the bud and flowering stage to reduce air and soil moisture. The rapid occurrence of downy mildew is often caused by flood irrigation, continuous moist soil and difficulty in draining moisture after watering on cloudy and rainy days. The excessive application of nitrogen fertilizer and the lack of phosphorus and potassium fertilizer resulted in excessive growth of stems and leaves and dense plants, which also decreased the host resistance and was easy to be infected with downy mildew. When local or punctate disease occurs in the greenhouse, if the diseased leaves are not removed in time and the ventilation condition is improved, it is very easy to cause secondary infection and a full outbreak. When most Platycodon grandiflorum plants in the field have been infected by downy mildew and the leaves are yellowed and rotted, the effect of chemical control is not ideal or ineffective, and when the cost is very high, consideration should be given to removing the diseased plants or retaining only the old piles at the base. Recover the economic loss through the next crop of production.

3. Healthy seedling

Studies have shown that Platycodon grandiflorum seeds may carry downy mildew spores. The seedling period of Platycodon grandiflorum is nearly 3 months, and the plants are very dense before coming out of the nursery. Platycodon grandiflorum can expand rapidly after being infected or carrying downy mildew at seedling stage, resulting in yellowing of seedlings and stagnation of growth. Platycodon grandiflorum has the saying of "seedling half production", which means that if the seedling is good, it is half successful. Therefore, it is very important to use healthy and disease-free seedlings.

4. Chemical control

Most of the agents are mainly used before and in the early stage of the disease. In the prone season, protective agents without internal absorption were sprayed every half a month, such as mancozeb, chlorothalonil, mancozeb and so on. Platycodon grandiflorum is sensitive to bacteria, and continuous spraying of chlorothalonil is easy to inhibit growth. According to foreign studies, ethylphosphine aluminum, azoxystrobin, aldicarb hydrochloride and metalaxyl manganese zinc are more safe to Platycodon grandiflorum. Others such as enoylmorpholine, carbendazim, chlorobromoisocyanuric acid, Trichoderma and Silverfarin are available to choose from. Internal inhalation fungicides are easy to produce drug resistance, the frequency of drug use in a single season is limited, and attention should be paid to the rotation of drugs. The general disease site is the back of the leaf, spray should be aimed at the back of the leaf as far as possible, the fog particles are fine, uniform and consistent.

What are the methods of flower pest control?

With the improvement of people's living standards, the construction of green families is more and more favored by people, and flowers are planted more and more widely. However, there are often pests in family flower cultivation, which not only affect the healthy growth of flowers and trees, but also hinder viewing. How to prevent and control diseases and insect pests is a problem often discussed by friends who love to grow flowers.

Generally speaking, the environmental conditions suitable for the growth and survival of family farmed flowers also create conditions for the occurrence and prevalence of many diseases and insect pests. The occurrence of diseases and insect pests depends on temperature sooner or later, and the severity of diseases and insect pests mainly depends on humidity in addition to the influence of temperature. In order to prevent and control diseases and insect pests, we should grasp the principle of "giving priority to prevention", strengthen management, and pay attention to ventilation, light transmission, watering, fertilization and other maintenance work. Make flowers and trees grow and thrive and enhance their ability to resist diseases and insect pests. Once diseases and insect pests are found, measures should be taken as soon as possible to achieve "early treatment, small treatment, and treatment" to prevent spread. When necessary, use chemicals to control, inhibit and kill diseases and insect pests, eliminate the threat of diseases and insect pests, and ensure the healthy growth of flowers.

The common pests of family flowers are aphids, red spiders, mosquitoes and flies (bacteria and flies), thrips, shell insects, whitefly, etc., and diseases include anthracnose, brown spot, soft rot, root rot (black stem disease), powdery mildew and so on.

Generally speaking, there are two main methods of flower pest control: culling and insecticide.

1. Culling

Pests with large individuals and small numbers, such as beetles, scale insects and larvae of Coleoptera, are caught and killed as soon as they are found.

2. Drug killing

That is, the toxicity of drugs is used to kill pests. Different types of drugs are sprayed according to the mouthparts of pests. Pests of mouthparts, such as beetles and pteroptera larvae, can be sprayed with stomach poisons and pesticides to kill them. Pests of piercing mouthparts, such as aphids, scale insects, whiteflies, etc., can be sprayed with internal inhalant pesticides to kill them. Contact pesticides can be sprayed on soil pests, such as beetle larvae, grubs, golden needle worms, nematodes, etc.

Here's a summary of some of the most common pest control methods:

Common insect pests and harmful small animals and their control

I. aphids

Harmful traits: aphids are bluish yellow insects that harm almost all flowers and trees. Between spring and summer, it is often concentrated on new shoots or buds such as rose, pomegranate, oleander and chrysanthemum, sucking liquid juice with mouthparts, causing tender leaves to curl and atrophy, seriously affecting not only growth and flowering, but also plant leaves curling and withering, producing galls and spreading virus disease. When aphids suck juice, they will discharge a sticky liquid called honeydew to stick to the leaves, attracting ants and causing mildew at the same time. Aphids can produce 20 million 30 generations a year, and eggs can survive the winter.

Harm to flowers: a wide range of hosts, mainly harmful to rose, pomegranate, oleander, chrysanthemum, carnation, chrysanthemum, cyclamen, hibiscus, bauhinia, poinsettia, melon and leaf chrysanthemum and other flowers.

Prevention and treatment: when a small amount occurs, it can be extruded with something, and then rinsed with water; it can also be smeared with tobacco water (50 times liquid) and soapy water for several times. Chemical control can be used to control aphids by spraying 25% fish rattan essence 800ml 1000 times, 40% chloromethoate 2000 times, 3% natural pyrethrum 1000 times and deltamethrin 2000000 times, all of which can kill aphids very well, and the effect is satisfactory.

2. Red spider

Harmful traits: red spider body is small, red, it is difficult to see with the naked eye. Often clustered on the back of the leaves of flowers and plants, sucking juices with prick mouthparts to harm the plants, making the leaves yellow-white spots, and then gray-white, so that the leaves scorched or fell off. It can occur for more than 10 generations a year, often growing in an environment of high temperature and low humidity. Harmful flowers: widely distributed, miscellaneous eating habits, almost all ornamental plants such as herbs, woody plants, cut flowers, potted flowers and so on may be harmed. Often harm azaleas, roses, a string of red, begonia and real cypress, kumquat, generations, cactus, cypress and so on, of which azaleas and cypresses suffer the most. It usually occurs more often in high-temperature and dry environments (such as indoor sunny windows, etc.) and propagates quickly.

Control methods: remove weeds in the basin and eliminate overwintering eggs. When a small amount occurs, the seriously infected leaves can be removed and washed with water; improve ventilation conditions, reduce the temperature; often spray more water around the plant to increase air humidity. Acaricides, such as butyl ether urea, avermectin, pyridaben, methamphetamine, amitraz, dicofol or omethoate, were alternately sprayed on the leaves of red spiders at the initial stage of the occurrence of red spiders, once every other week.

Mosquitoes and flies (bacteria and flies)

Harmful characters: the main food of larvae is plant pathogenic saprophytic fungi, and the result of feeding by larvae leads to the infection of plant pathogens through roots. Mosquito and fly larvae feeding on flower roots reduces the ability of flowers and plants to absorb water and nutrients, which makes the plants grow slowly and dwarf. In addition, mosquito and fly feeding can also cause flower Pythium, blight and black root rot.

Harmful flowers: it is common to grow seedlings with potted flowers or grass flowers, such as poinsettia, cyclamen and pansy.

Prevention and control methods: chemical control, the use of Huifu (Citation), Huijian, avermectin and other agents through root irrigation to prevent and control mosquitoes and flies larvae.

4. Thrips

Harmful characters: thrips black or brown, common flower thrips, tobacco thrips, yellow thrips and western flower thrips, serious damage period is spring and summer. Thrips often file juice harm at the back of tender leaves and floral organs, so that the injured leaves curl, the mesophyll appears yellow file spots, and the injured leaves turn yellow, brittle and fall off. Sometimes there will be gray-white or brown spots on the petals, or discoloration, discoloration and other phenomena that affect the quality of flowering.

Harmful flowers: anthurium, cyclamen, roses, carnations, Platycodon grandiflorum and other flowers.

Control method: because it can produce resistance to many insecticides, physical, chemical and biological methods are used in production. Chemical control uses Huijian, lice acaridourea, Huijian + kungfu, avermectin, doxorubicin and other agents to alternate foliar spray for 5 to 7 days.

5. Scale insects

Harmful characters: there are many kinds, such as powder worm, red wax shell worm, blow cotton shell worm, brown round shell worm and so on. It is one of the common pests in indoor foliage plants, especially in woody foliage plants and coniferous plants. It is mainly parasitic on the young stems and leaves of plants and uses piercing mouthparts to insert plant tissues to absorb juice. The wound is easily infected with diseases and can induce soot disease. Its fecundity is very strong, and it can reproduce many generations a year when the environmental conditions are suitable, so it can cause damage every year in areas with higher temperatures.

Prevention and control methods: when a small amount occurs, it is usually controlled manually, that is, remove the worm with a brush and rinse it with water. Chemical control is best carried out during the peak incubation period of nymphs whose waxy shell has not yet been formed on the surface of the insect body, so that it is easier to kill the insect body and can improve the control effect. The medicament can choose 1000 times liquid of isocarbophos, 1500-2000 times of fenvalerate, 800 times of omethoate and 1000 times of omethoate, spraying 2 or 3 times every other week. If the occurrence is more serious, it is necessary to use a combination of artificial and chemical prevention and control methods, that is, first use a brush to remove the medium, and then spray with the above-mentioned agents, so that the effect is more ideal.

6. Whitefly

Harmful characters: widely distributed, harmful to a variety of flowers, indoor foliage plants often occur in greenhouses or plastic greenhouses, especially in dry environment. The insect body is small and white, and the mouthparts of adults and larvae are inserted from the back of the leaves to absorb the juice, making the leaves withered and yellow. The wound is prone to brown rot, which can lead to plant death in severe cases. At the same time, Honeydew is excreted on the leaves and causes soot disease.

Prevention and control methods: 2.5% deltamethrin, 20% fenvalerate 1500Mel 2000 times solution and pyrethroid and other pesticides can be sprayed to control nymphs, adults and eggs, usually once a week for 3 consecutive 4 times.

7. Underground pests such as nematodes and grubs

Harmful characters: this kind of pests mainly bite the roots and tender stems of plants in the ground, or damage the root corms, resulting in root and stem rot and plant death.

Control methods: disinfect the soil with steam or medicament to put an end to nematodes and other root causes; mix food with trichlorfon and sprinkle it or bury it next to seedlings for trapping; irrigate plants with 1000 times of trichlorfon solution; kill manually.

8. Snails

Harmful traits: small terrestrial molluscs, mostly living in a humid environment for years. Like Yin dampness, afraid of dryness and strong light. It often harms the leaves, tender stems and roots of perennial herbaceous foliage plants, makes the branches and leaves of the plant incomplete, affects the growth and ornamental of the plant, or makes the plant die.

Prevention and control methods: you can scatter trichlorfon and trichlorfon food in its regular activity place; spray around the plant with trichlorfon and deltamethrin 1500 / 2000 times; spread 8% Mianhuoling granule on the soil around the root agent to kill snails. In addition, pay attention to indoor cleanliness, timely removal of withered branches and leaves, reduce its living space.

Here are the general methods of pre-prevention and control of flower diseases and insect pests:

The main results are as follows: 1. Keeping the environmental hygiene of flower cultivation can reduce the harm.

2, protect the plant, do not break the skin, be injured, beware of germs invasion.

3. Pre-disinfection of culture can kill germs and pests.

4. Strengthen daily management, keep proper water and fertilizer, smooth air, suitable temperature and daylighting, so as to make the plant grow healthily and control the breeding and spread of diseases and insect pests.

5. Outdoor overwintering flowers, spray or smear stone sulfur mixture after falling leaves, spray Bordeaux liquid 1-3 times in early spring and before flower bud germination, wither and control diseases and insect pests. The seedlings sown with blight appeared scalded near the surface at first, then softened and fell to the ground and died. Sprinkling plant ash or irrigating ammonium solution on the surface of basin soil can sterilize and protect seedlings. There are orange or yellow spots on the leaves of carnation and Rosaceae flowers at the initial stage, yellow powder on the back at the later stage, brown spots on the peel before the blossom and decline of the leaves, and then spray 1-3 times or carbendazim mixture or carbendazim powdery mildew on both sides of the leaves of Rosaceae and Compositae flowers to reduce humidity. Spraying Bordeaux solution with Dysenamine or carbendazim solution to prevent the appearance of white spots on the leaves of herbaceous flowers with unconspicuous outline at the initial stage, and spraying Bordeaux solution with white fine hairs for 1-3 times in the later stage could prevent water-immersed spots on the leaf surface of herbaceous flowers with soft rot, and droop Bordeaux solution behind the face. Brown streak orchid flowers appear brown sunken spots on the leaves, dry coke leaves pay attention to shade and improve air humidity, the same amount of Bordeaux liquid black rust Compositae flowers appear yellow-green spots in the early stage, fly yellow powder after rupture, and finally turn black patches to strengthen drainage, full sunshine, strengthen ventilation and spray Bordeaux liquid. Soot disease perennial evergreen flowers appear dark brown coal stain on the leaf surface, and then gradually expand to form a black soot-like mildew layer to spray Bordeaux solution, or use 5% alcohol to detect the coal pollution.

Now let's introduce several common methods for the prevention and control of flower diseases and insect pests.

1. Tobacco has the effects of stomach poison contact and fumigation because it can cause nerve paralysis and poisoning of pests. The use of tobacco leaf stalks or leftover cigarette butts (to remove the filter tip) is to soak in water 50 times and 60 times for one day and night, and then spray to control aphids, cotton red spiders and newly hatched shell insects.

2. The wind oil essence diluted 600 times to 800 times can control aphids, scale insects, moths and butterflies larvae, 400 times 600 times liquid can control cotton red spiders.

3. Mosquito spray can kill whitefly pests after hanging the ignited mosquito on the flowers and plants and filling the seam with plastic film for about 10 minutes.

4. Soapy water take general soapy water or use the rest of the soapy head flakes to be hydrated by hot hydration according to the proportion of 160 and cooled with water. Spraying can control aphids and cotton red spiders if soaking cigarette butts (removing cigarette ash) in soapy water can improve the control of aphids and red spiders. The detergent solution can kill aphids, scale insects, cotton red spiders, green thorn moths, pink butterflies, whitefly and other plants with tuberous roots (such as peony, dahlia) or bulbs (such as lilies, Lycoris radiata). Flowers and plants with fleshy roots are vulnerable to nematode risk, and flowers and plants with fleshy roots are vulnerable to nematode risk. 1000 times diluted detergent solution can also be used around the plant roots.

After dissolving soap and hot water at 150%, spraying soap can clog the respiratory organs of pests to their extinction to aphids and scale insects. Effective tobacco liquid containing nicotine has a strong contact killing effect on aphids, cotton red spiders, ants and so on. It also has fumigation and stomach toxicity. Take 20 grams of tobacco or cut tobacco and soak 500 grams of water for 24 hours, then add 2% soap water 500 grams to spray on the leaves infected with insects. The filtrate can also be sprayed directly on the basin soil and around the basin bottom without soapy water to kill pests in the soil.

Garlic solution for powdery mildew and black spot disease, 30 grams of garlic, 500 grams of water, 500 grams of water.

After 50 grams of green onions were pounded into mud and soaked in water for 12 hours, filtrate was sprayed with filtrate for 3 times a day for 4 days to control software pests such as aphids and powdery mildew.

The new ginger juice can be mashed and soaked in water 20 times for 12 hours, and then sprayed with filtrate can control leaf spot, coal pollution, rot, black spot, aphids, cotton red spiders and leafminers.

Zanthoxylum bungeanum liquid 50 grams plus 500 grams of water, heat and boil in the pot to 250 grams of medicine liquid, add water 6 to 7 times spray to control whitefly, aphids and scale insects

The citrus peel liquid was soaked in 50 grams of citrus peel and 500 grams of water for 24 hours. after filtration, the filtrate was sprayed to control aphids, cotton red spiders and leaf worms, and poured into the soil to control nematodes. In addition, one part of citrus seeds can be soaked in 5 parts of water for 4-5 days, and then the ovules of flowers and plants can be soaked in this solution for 10 minutes to control many kinds of pests. Balsam pear leaf liquid will mash balsam pear leaves 100g, 200g, add water and the same amount of lime to mix evenly, irrigate the roots of plant seedlings, and control Dishan king. Tomato leaf liquid 50 grams of fresh tomato leaves mashed and 150 grams of water soaked for 6 hours, then sprayed with filtrate to control aphids, cotton red spiders and other flies.

Take 50 grams of chili pepper and boil it with 10 times water for 20 minutes, then filter and spray the filtrate to control aphids, cotton red spiders, stink bugs and other pests to control soil silkworms.

Castor leaf powder dried castor leaves and stems, ground them into powder and applied them to the soil to control grubs.

Oleander solution 50 grams of oleander branches and leaves and 100 grams of water boiled for 20 minutes to remove the residue for 30 minutes to spray to control aphids and whitefly poured into the soil to control nematodes but pay attention to the toxicity of oleander and beware of human and animal feeding.

Rice vinegar containing rich organic acids has a good inhibitory effect on bacteria. Spraying 150 × 200 times diluted rice vinegar on the leaf surface for 3 times every 7 days can control powdery mildew, black spot, downy mildew and so on.

Take 5 grams of baking soda solution, also known as sodium bicarbonate, first dissolve it with a small amount of alcohol, and then add about 1000 grams of water to form a 0.5% concentration solution to spray plants to control powdery mildew.

Mosquitoes, mosquitoes, mosquitoes,

Potassium permanganate solution, commonly known as gray manganese oxygen potassium permanganate solution, can control powdery mildew of flowers and herbs. spray 0.1% 0.2% solution for 7 days and spray 2 times for 3 times for more than 92%. Do not touch potassium permanganate solids directly.

Common insecticides and fungicides

Common insecticides 1. Trichlorfon is a kind of organophosphorus preparation with high efficiency and low toxicity, which has strong stomach toxicity and contact toxicity to pests. 1000-1500 times liquid spray is commonly used in 4-5 days in the field to control rose leaf wasp, coir moth, quasi-short-forehead negative locust, cotton leaf borer, inchworm, leafhopper, small mountain king and other pests. Trichlorfon can not be mixed with alkaline agents.

2. Dichlorvos is a highly efficient and low toxic organophosphorus preparation with strong contact fumigation gastrotoxicity, wide range of insecticidal effect, fast efficacy, short residual period, commonly used 50% EC 1000 times or 80% EC 1500 times spray control of whitefly leaf mites, green blind aphids, scale insects, pomegranate armyworm and other pests pay attention not to mix with alkaline agents dichlorvos EC volatile medicine should be capped when the concentration is high, it is easy to cause harm to cherry blossoms and plum blossoms.

3. Omethoate has the effects of contact, internal inhalation and stomach toxicity, which can control the acute gastric toxicity of many piercing and chewing mouthparts pests to human and animals. 40% EC 1000-1500 times liquid spray to control scale insects, aphids, white powder lice, Chen sand leaf mites, green blind bugs, thistle leafhoppers, citrus leafhoppers, citrus leafhoppers and other pests cannot be mixed with alkaline agents.

4. Dimethoate is a broad-spectrum organophosphorus pesticide with high efficiency and low toxicity. Generally, 40% EC 1000-1500 times or 60% wettable powder 3000-5000 times are used to control aphids, cotton, red spider, leafhopper, leafhopper, whitefly and other pests. 1 gram of medicine can also be used to mix seeds with 20-40 grams of water to control mole cricket and other underground pests. Plum blossom cherry blossoms should be careful not to be mixed with alkaline agents.

5. Malathion has contact stomach toxicity and fumigation effect, high efficacy, wide range of insecticidal effect, generally less toxic to humans and animals in one week, 50% EC 1000-2000 times liquid spray to control aphids, cotton, red spider, leaf cicada, scale, scale, beetles and other pests, malathion is not stable for too long and cannot be mixed with alkaline or strongly acidic pesticides

6. Monocrotophos has strong contact effect, both internal absorption and stomach toxicity, wide range of insecticidal efficacy, a week's control of 50% EC 2000-4000 times spray to control aphids, cotton, red spiders, leafhoppers, thrips, green bugs and other pests should not be mixed with alkaline pesticides.

7. Fenitrothion is a broad-spectrum insecticide with contact and stomach toxicity or killing borer pests in 3-4 days. 1000 EC 50-2000 solution is generally used to control aphids, pods, leafhoppers, heart-eating insects, scale, thrips, mites and other pests. 2% powder spray control dosage is generally 1-3 grams per square meter to cruciferous plants can not be mixed with alkaline pesticides.

8. Deltamethrin has strong contact toxicity and stomach toxicity, and the drug effect can be as long as several months. 2.5% EC is commonly used to spray 3000-8000 times to control diamondback moth, cotton leaf borer, thistle, leafhopper, etc.

9. Trichloroacarone is a kind of acaricide containing organochlorine, which has a strong contact effect on killing young mites and eggs. It can crush the physiological function of mites so that it can be infertile for a period of up to one month. Commonly used 20% wettable powder 800ml powder solution or 50% wettable powder 1500-2000 times spray to control mites.

10. Dicofol has a strong contact effect on mites, eggs, larvae, nymphs, adults, effective residual period of 10-20 days commonly used 20% EC 600-1000 times or 40% EC 1000-1500 times spray control of all kinds of mites can not be mixed with alkaline pesticides

1. Carbofuran is a broad-spectrum insecticide with low residual toxicity, which can control chewable and piercing mouthparts insects and nematodes. 3%, 5%, 10z5 granules and 75% wettable powder can control nematodes, scale mites, leafhoppers, moths, aphids, thrips and other pests can not be mixed with alkaline pesticides.

12. The dark brown liquid made of couplet nasal spray and caustic soda boil is strongly alkaline and has contact effect. It is often sprayed 8-12 times in winter dormancy or 10-18 times in growing season to control scale insects, whitefly, cotton, red spiders and other pests.

13. Aldicarb has the effect of contact internal inhalation and fumigation. Generally, 25% wettable powder 200,400 times or 20% EC 1000-1500 times are commonly used in 2-3 days to control leafhopper aphids, whitefly, scale insects and other pests should not be mixed with alkaline pesticides.

Common fungicides

Bordeaux liquid is a good protective fungicide composed of copper sulfate, According to the difference in the amount of copper sulfate and quicklime, the preparation of quicklime and quicklime can be divided into equivalent type 11, semi-quantity type 10.5 multi-quantity type 13 and double type 12, etc. in the preparation, each half of the hydrated copper sulfate and quicklime are used, and then the copper sulfate is poured into the quicklime solution and stirred evenly with a stick, the Bordeaux colloid suspension with sky blue can be prepared with strong alkaline adhesion on the plant surface. The period of validity of forming a film can be maintained for half a month. Bordeaux liquid intolerant storage must be mixed with alkali pesticides to prevent black spot disease. Rust, downy mildew, gray spot and other diseases

II. Stone-sulfur mixture is also a protective fungicide prepared by boiling quicklime sulfur powder and water in the proportion of 1210. When the original liquid is dark reddish brown transparent liquid with smelly egg flavor and alkaline preparation, first boil the water in the pot, pour in 1 part of quicklime and other lime to dissolve, then add 2 parts of sulfur powder which is first adjusted into paste with a small amount of water while stirring and boiling over high fire for 1 hour. After cease-fire cooling, the filtered sediment is the original solution of stone-sulfur mixture, and its Baume filling degree is generally 20-24. Before use, the original solution must be diluted and sprayed during the dormant period. Baume 3-5 degree growth time can only use Baume degree 0.3-0.5 diluent to control powdery mildew, downy mildew, perforated leaf spot and other diseases, as well as whitefly leaf mites, mites, insect pests and other pests.

Chlorothalonil has protective and therapeutic effects, wide range of germicidal efficacy, long residual effect on skin and mucosa, commonly used 75% chlorothalonil wettable powder 600-1000 times liquid spray prevention.

Experts comment on the market of main cut flower varieties in July

Lily volume reduction, price reduction, partial rebound

In July, various lily producing areas have reduced the amount of flowers, and the prices of lilies in the fresh cut flower wholesale markets vary from place to place, rising and falling.

In the Kunming market, except for 'Huang Tianba' due to a reduction in production and a rebound in prices, the wholesale prices of other varieties have fallen to varying degrees. The average price of a long-headed 'Huang Tianba' is 65 to 70 yuan per bundle, 45 to 50 yuan per tie for three heads, 35 yuan to 40 yuan for each tie on both ends, and 18 yuan to 20 yuan on a single head, with an average price of more than 10 yuan higher than last month. In contrast, the average prices of Siberia and Sorbonne have dropped by more than 10 yuan, with little difference in wholesale prices, ranging from 25 to 30 yuan for long-headed products and about 10 yuan for single-headed and double-headed products. The wholesale price of 'Tiber' has also dropped a lot, with long-headed products falling from 40 yuan to 30 yuan per pack, while double-headed products only 13 to 15 yuan per pack. The wholesale price of 'Robina' is 11 yuan per bundle, 16 to 20 yuan for each bundle at both ends, 26 to 30 yuan for 3 flowers, and 45 to 50 yuan for bullish ones. Industry insiders say they are more optimistic about the lily market in August. The price of 'Sorbonne' will rebound in the next few days, and the price of bullish products may rise to more than 60 yuan per bundle or even higher, while the price of 'Siberia' will double later.

Lingyuan market listing volume of lilies dropped sharply in July, due to the hot weather, the quality is also poor, showing a small bud. Most of the products on the market are second stubble flowers, and the overall price of lilies is less than 20 yuan each. "Siberia" with more than three heads costs 20 yuan each, and each bundle at both ends costs seven or eight yuan. The 'Sorbonne' above three heads costs fifteen or sixteen yuan each, and each tie at both ends costs seven or eight yuan. The long-headed 'wooden door' is 11 or 12 yuan per tie, and the two ends are 3 to 5 yuan each. The bulls' dazzling'is five or six yuan per tie. Wholesalers said that the seeds planted in mid-August and the first half of the year will enter the flowering stage, with better quality, when the price will pick up.

However, the sales performance of lilies in the Shanghai market has bucked the trend, and the prices of various products have risen to varying degrees compared with June. The average prices of mainstream products' Siberia 'and' Sorbonne 'have increased by 5 to 8 yuan per bundle last month, including 35 to 50 yuan for bullish Siberia, 15 to 20 yuan for both ends, 10 to 12 yuan for single head, 40 to 45 yuan for long' Sorbonne 'and 18 to 20 yuan for 3 heads. The price rise is due to the fact that there is no supply of finished flowers in Haining, Zhangjiagang and other lily producing areas recently, and a small number of listed products are affected by rain and high temperature, and the quality is poor. Like the Kunming market, the price of "Huang Tianba" in the Shanghai market rose the most this month, with bullish products ranging from 50 yuan to 55 yuan per bundle, compared with only 30 or 40 yuan per bundle in June. It is understood that the main factor causing this phenomenon is that there are relatively few yellow flowers in the market, and there is a general shortage of 'Huang Tianba' across the country, so it is very difficult for wholesalers to find goods, so prices are rising day by day.

Commentator: Xu Guolin, sales Director of South China region of Xinuo (Beijing) Flower seed Industry Co., Ltd.

Wang Fenglai of Liaoning Lingyuan Flower Technical Service Department Jiang Haitao of Shanghai Yuechen Flower Trading Company

The price fell in the early stage of the rose and rebounded later.

Due to the heavy rain in many parts of the country in July, and the rising temperature after entering the midsummer, the quality of cut rose in Kunming can not go up, and the proportion of A-grade flowers in the market is very low, which makes the overall market very weak. At present, although the number of roses listed in Yunnan in July is about 5% higher than that in June, prices are much lower than in June, by 40% to 50%. In addition to the weak consumer market caused by floods in various places, the high temperature and rainy weather in July made the greenhouse in cut rose producing areas have high humidity, many diseases and insect pests, and flower heads are easy to rot and wither, which brings great difficulty to the maintenance work of florist after restocking, so they do not dare to restock in large quantities. However, with the arrival of "Qixi Festival" Valentine's Day and other festivals, the price of the rose began to rebound at the end of this month, and sales also rose sharply.

The average price of 'Carola', the mainstream red variety in Kunming Dounan market, is 8 yuan per bundle, of which the price of grade A goods is about 14 yuan per bundle, which is much higher than that of the first half of the month, but the total amount listed on the market is very small, less than 15% of the price of grade B products is 89 yuan per bundle. Domestic market consumption is mainly C-grade flowers, accounting for 50% of the total market, and the price is 4 yuan to 6 yuan per bundle. In contrast, the price of miscellaneous rose rose by a large margin, and has basically returned to the level of June. Among them, the average price of grade An items such as' Fendra 'and' Maria'is more than 30 yuan per bundle, and some of them can even reach more than 40 yuan per bundle; the average price of grade B items is about 25 yuan per bundle; and the average price of grade C products is only about 8 yuan per bundle.

The overall auction price of Kunming International Flower auction and Trading Center on July 27 is 0.3 yuan per unit, but the average product price of many enterprises can reach more than 0.5 yuan per unit. After the weather turns hot, the price of light-colored rose rises quickly, and it is in the upper-middle level in the overall market. For example, the wholesale price of good quality 'Tannick' and 'Snow Mountain' can reach 1.2 yuan to 1.3 yuan each.

Guangzhou Lingnan flower market is dominated by 'Carola','90 'and other varieties, and the listing volume of' Cardinal'is lower than that in June. As a large part of cut rose flowers in Shenzhen, Hong Kong and other places pass through the Lingnan market, Kunming cut rose has a large sales volume in the Guangzhou market. The average wholesale price of high-quality products can reach 0.9 yuan per unit, 0.2 yuan higher than that in Kunming.

After entering August, with the decrease of Rain Water, the quality of cut rose will improve. The price of "Qixi Festival" before Valentine's Day is expected to rise and eventually reach about twice the price of the first ten days of mid-July. Since then, teacher's Day and Mid-Autumn Festival will follow one after another, and prices will not fall sharply.

Commentator: Xie Yaorong, General Manager of Kunming Hongri Flower Co., Ltd.

Wang Yanxin, sales Manager of Yunnan Lidu Flower Development Co., Ltd.

The oversupply of gerbera leads to a drop in prices.

The production of cut gerbera flowers has increased in all producing areas, but the price of cut gerbera flowers is lower than in June because of the decline in demand due to the off-season of consumption.

In July of last year, gerbera gerbera in Kunming entered the peak of seedling replacement, but due to the better price in the same period last year, growers generally postponed the time of seedling replacement, and the amount of flowers on the market was still relatively large, but the demand has decreased, so the price has dropped slightly. On the market, the average price of African chrysanthemum is 0.15 yuan each, of which the red 'savanna' is the highest, with an average price of about 0.18 yuan each. The wholesale price of orange variety 'overfire' is 0.11 yuan each, and that of pink 'Rosabel' is about 0.09 yuan. In addition, the wholesale price of medium-quality honey is 0.16 yuan each, Golden Sun 0.15 yuan, Dolly 0.17 yuan and Linglong 0.12 yuan each. Wholesalers expect that after August, due to the low price of gerbera, growers will begin to change seedlings one after another, and prices will pick up somewhat. However, it should be noted that sales of African chrysanthemum seedlings were very good in the first half of the year, and farmers snapped up one after another, causing prices to rise all the way, even more than 1.5 yuan per unit. This may lead to an oversupply of cut African chrysanthemum flowers in the second half of the year, and the price is worrying.

This month, the wholesale price of gerbera in Linyi, Shandong Province fell to two or three yuan per pack, down from three or four yuan last month. The main factor is the obvious decline in demand this month, which has really entered the off-season of sales. At present, the products on the market are still mainly old Miao flowers, with a flower diameter of 67 cm and a culm length of 70 to 80 cm, of which 'exquisite', 'gouache' and 'snow chrysanthemum' account for 60%. The new seedlings planted in spring have begun to blossom one after another, with a flower diameter of about 10 cm and a culm length of 40 to 50 cm. In August, the number of flowers from new seedlings will increase significantly, and dealers hope that the market situation will improve.

The price of African chrysanthemum in Guangzhou market is relatively stable, about 0.4 yuan for locally produced gerbera and 0.65 to 0.75 for Kunming goods, but the proportion of good quality products is relatively small due to the rainy season.

Commentator: Li Qimeng, a wholesaler in Kunming Dounan Flower Market

Xiao Xia, director of flower sales in Kunming Dounan, Guangzhou Huihuang flower Huang Yongfu

Cut grass flower Platycodon grandiflorum with high quality and few products

Among all the cut flower varieties, the grass cut flower market is relatively stable. The abnormal climate this year has led to an increase in the probability of Platycodon grandiflorum being infected with diseases and insect pests, so there are few high-quality products on the market at present.

Since the beginning of this year, the climate of Kunming is relatively special, coupled with the late rainy season, many Platycodon grandiflorum infected with downy mildew, gray mold, fungi and other diseases, resulting in a small number of high-quality products on the market. The general quality of purple edge Platycodon grandiflorum is the fastest, the wholesale price is about 12 yuan per bundle, and the vermicelli products are almost the same. The wholesale price of green and champagne Platycodon grandiflorum is relatively cheap, about 9 yuan per bundle. The wholesale price of pure purple products can reach 10 yuan per bundle, while the price of white products is even higher, 15 yuan per bundle. Wholesalers said that Platycodon grandiflorum has been used not only in flower bouquets, but also in weddings and flower baskets, so its price is expected to rise with the advent of "Qixi Festival" Valentine's Day. In the export market, due to the increase in the number of farmers planting Platycodon grandiflorum this year, the supply exceeds demand, so the price has dropped, the wholesale price is about 28 yuan per bundle. The wholesale price of goldfish grass is 8 yuan to 11 yuan, good quality delphinium grass 4.5 yuan to 5 yuan, carnation plum 14 yuan to 16 yuan, violets about 10 yuan. Cockscomb is 5 to 8 yuan per bundle. Sunflowers with 1.5 meters long branches and half-blooming flowers up to five or six centimeters in diameter are wholesale priced at 1.5 yuan to 2 yuan each.

In July, the supply of goldfish grass in the Beijing market was relatively small, with a wholesale price of about 10 yuan per bundle. The market of swallow grass is relatively good, and the wholesale price of products with a culm length of 80 or 90 centimeters is as high as 6 yuan each. On the Guangzhou market, the wholesale price of goldfish grass is 15 or 16 yuan per bundle, and that of delphinium grass is about 5 yuan each. The wholesale price of Platycodon grandiflorum is 28 yuan per bundle, and the average price of variegated products is one or two yuan lower. The number of cockscomb on the market is relatively small, and the wholesale price can be sold at about 2 yuan each. Sunflowers with a culm length of about one meter and a flower diameter of 8 to 10 centimeters are currently wholesale at 1.5 yuan to 2 yuan each.

Commentator: Kunming Lishen Xinyuan Flower Co., Ltd. Xiong Shangkun

Kunming Qianhui Seedling Co., Ltd. Yang Yun Beijing Laitai fresh cut flower wholesaler Yao Jiayong

Cut leaves to get rich at high temperature and the quality of expensive bamboo is slightly inferior.

July has entered the off-season of flower consumption, and the market for cutting leaves is generally lower than that in June. The quality of rich bamboo, which is preferred by family consumers, is slightly worse during this period of time, and the price is also lower than that of the same period in previous years.

In June, Hainan remained at a high temperature of more than 35 ℃, even lasting from 38 ℃ to 39 ℃ for one week. The rich bamboo with shallow root system has insufficient water supply, which leads to the drying of leaf tip and reduces the ornamental value. At present, the wholesale price of 75 cm long rich bamboos in Hainan is 4 yuan per bundle, 3 yuan per bundle for products with 60 cm to 75 cm branches, and 2 yuan per bundle for products with 50 to 60 cm long branches. With the advent of the rainy season in July, the growing environment of rich bamboo has improved, and wholesalers expect prices to pick up in September. Overall, the wholesale prices of all cut leaves in Hainan have fallen by about 10% compared with June, with large shipments of sunflower, Brazilian leaves, tortoise back leaves, fishtail leaves and sword leaves. Loose-tailed sunflower is divided into three specifications, the wholesale price is 1.3 yuan per bundle with a length of 60 cm, 2 yuan per bundle with a length of 80 cm and 3 yuan per bundle with a length of 1.1 meters. Brazilian leaves are sold at a wholesale price of 0.45 to 0.6 yuan per bundle. The wholesale price of tortoise back leaves is one or two yuan each according to the size of the palm. The wholesale price of fish tail leaves with branches 50 cm long is 0.5 yuan per bundle, and 0.65 yuan per bundle with more than 70 cm long. The wholesale price of sword leaves is 0.8 yuan per tie. In addition, the wholesale prices of Penglai pine, angel leaf, spring rain leaf, cycad leaf, alpine fern tooth and sunflower leaf are 3 yuan, 1.5 yuan, 2.5 yuan, 2 yuan, 5 yuan and two or three yuan respectively.

The price of cut leaves in Shanghai market has not changed much compared with June, but the sales volume has decreased significantly, especially Fugui bamboo. According to the analysis of wholesalers, in addition to the decline in product quality, hot weather is also a major factor. This season, most consumers choose to go out less, and the rich bamboo, which was favored by family consumers, has also been put into the "cold palace". On the market, the wholesale price of rich bamboo is only 6 yuan per bundle, but the volume is very small. Brazilian leaves and loose-tailed sunflower have a wide range of uses, which can be used for both flower arrangement and site layout, so July sales are relatively best, with the wholesale price of Brazilian leaves at 1.5 yuan per bundle and loose-tailed sunflower at 2 yuan to 4 yuan per bundle according to palm size. The price of Haitong leaves in Jiangsu and Zhejiang is not bad, about 1 yuan per bundle of wholesale price.

The leaf-cutting market in Kunming has not changed much this month. The wholesale price of fish tail leaves is 1.2 yuan per bundle, and that of Brazilian leaves is about 2 yuan per bundle. The wholesale price of sunflower varies from 3 yuan to 5 yuan per bundle according to the specifications. The wholesale price of sword leaves with branches ranging from 50 cm to 100 cm is 1.5 yuan to 4 yuan per bundle. The wholesale price of ivy is seven or eight yuan each. The wholesale price of Penglai pine with 20 cm to 60 cm branches is 6 yuan to 15 yuan per bundle. The wholesale price of star anise gold plate is four or five yuan per bundle, and the tortoise back leaf is five or six yuan per bundle.

Commentator: Zhang Jiming, sales Manager of Hainan Daxin Garden Co., Ltd.

Yu Changbing, a wholesaler of leaf wood in Shanghai Caojiadu Flower Market

Xiao Xia, director of flower sales in Dounan, Kunming

The price of carnations is stable and getting better.

Compared with June, the carnation market in Kunming improved significantly in July, with a good situation of both volume and price rising, especially the rapid growth in export volume. Some large manufacturers in Kunming have exported more than one million carnations to Japan, virtually boosting sales of carnations.

However, the price of red varieties in Kunming Dounan flower market is still not ideal, such as the better quality price of the mainstream variety 'Master' is only about 0.2 yuan each. The main reason for the low price of red varieties is that farmers are not very good at management during this period of time, resulting in slender branches, small flower heads, and the quality is not up to standard. The prices of other color products are higher, such as' pretty Bride', 'rouge' and 'Red Lovers'. The wholesale price of better quality can reach 0.4 yuan each, while the single price of export products ranges from 0.55 yuan to 0.6 yuan. The sales of multi-headed carnations are better than single-headed products, such as the better quality pink long-headed variety 'Barbara' whose export price reaches 0.6 yuan each. In addition, the prices of green varieties' Green Lady 'and white varieties' Snow White', which are in tight demand in the export market, are still high, with the single price of 'Green Lady' about 0.6 yuan and Snow White reaching 0.7 yuan. The domestic demand is mainly red and pink varieties, and the prices of 'Red Lovers', 'Flame' and 'Fandai' are 0.2 yuan to 0.3 yuan each.

In terms of seedlings, due to the peak sales period, the price of seedlings has dropped to about 0.2 yuan per plant, 0.1 yuan lower than the average price in June. Compared with previous years, the price of seedlings is still good, and products of lower quality can be sold at about 0.18 yuan per plant. Seed and seedling merchants said that due to the investment in seedling equipment and technology by large enterprises, coupled with the use of imported female parents, the quality is much higher than that of small workshops, so the current polarization of the seedling market is very serious. High-quality brand seedlings are in short supply, but small-scale seedlings are difficult to sell.

Dealers said that after "Qixi Festival" Valentine's Day, the price of carnations may fall slightly, and the number of carnations listed on the market in September and October will be more than double that of now, and prices should continue to fall.

Commentator: Xie Yaorong, General Manager of Kunming Hongri Flower Co., Ltd.

Zhou Peisheng, General Manager of Sichuan Xichang Tianxi Horticulture Co., Ltd.

The market performance of flower matching is good except for Orioles.

In July, the main producing area of flower matching, in addition to the poor market of Huang Ying, the market volume of other products decreased compared with the same period in previous years, resulting in a doubling of prices, the most obvious being all over the sky and forget-me-not.

The wholesale price of Mantianxing on the Kunming market has reached 20 yuan per kilogram, which is more than 10 yuan lower than that in June, but more than double that of 78 yuan per kilogram in the same period in previous years. Not only is the market of Manchurian Star better, but no one bought it at a wholesale price of a few cents per kilogram last year. This year, the price has reached eight or nine yuan. Although the product quality has declined due to the rainy season, the market has maintained a high level. Wholesalers analyze the reasons that most of the flower farmers who originally planted Mantianxing and forget-me-not were distributed near Dianchi Lake, but due to factors such as their transformation and the construction of Kunming New Town, these flower farmers have lost their planting base, and some people are no longer engaged in production. Coupled with the impact of this year's dry climate, the listing volume of Mantianxing and forget-me-not has dropped significantly, and prices have rebounded. However, the market performance of Orioles is not good. Except for Kunyang in Jinning, plants are more or less planted all over the country, which can meet the needs of the local or surrounding markets. Therefore, the quantity of Orioles purchased from Kunming is relatively small, resulting in a situation that supply exceeds demand. The wholesale price of good quality Orioles on the market is 2 yuan to 2.5 yuan per bundle, and less than 1 yuan per bundle of poor quality. In addition, despite the decline in demand, due to a greater decline in market volume, the wholesale price of lover grass per kilogram rose 2 yuan from June to about 18 yuan. The price of fire dragon ball is relatively stable, 5 to 10 yuan per bundle. Hydrangea varies according to color, the wholesale price is 8 yuan to 13 yuan each, the white one is the cheapest, light blue and light pink are relatively expensive. Wholesalers predict that with the advent of "Qixi Festival" Valentine's Day, the prices of flowers such as full stars, forget-me-not and love grass will rise in August, which may reach three or four yuan per kilogram.

The price of Orioles in Guangzhou market is also very low, the wholesale price of 10 sticks per bundle is only 34 cents, mainly produced locally. All over the sky, love grass and other flowers from Kunming, so the market is relatively good. The wholesale price of Man Tianxing is 40 yuan per kilogram, lover grass is more than 20 yuan per kilogram, forget-me-not is 12 or 13 yuan per kilogram, and dragon ball is 10 to 12 yuan per tie. There is little stock in the evening foggy grass market. Pure white, purple, pink and other hydrangeas are about 10 yuan each, but light blue hydrangeas can be sold for 14 or 15 yuan each.

Commentator: Li Qimeng, a wholesaler in Kunming Dounan Flower Market

Huang Yongfu, Huihuang Flowers in Guangzhou

The prices of other cut Anthurium andraeanum tropical orchids are rising.

Sales off-season, in addition to Cymbidium and Phalaenopsis cut flower performance in general, Oncidium, Anthurium, Dendrobium and other prices have risen to varying degrees.

In July, the supply of cut Cymbidium and Phalaenopsis cut flowers in the Beijing market was intermittent and unstable. The wholesale price of green Cymbidium was 70 to 80 yuan, and that of Phalaenopsis cut flower was 30 to 60 yuan per bundle. Compared with the same period in previous years, the wholesale prices of Anthurium andraeanum, Oncidium and Dendrobium have all increased. This summer, the demand for Anthurium andraeanum has increased, and the wholesale price has risen from two or three yuan last year to 3 yuan to 5 yuan, among which the palm diameter of high-quality products can reach 10 cm. Grade An Oncidium is 30 yuan per pack, B grade products is 25 yuan per pack, C grade is 18 yuan to 20 yuan per pack, and the culm length is 50 to 60 centimeters. The unrest in Thailand in the first half of the year also affected its flower industry, and the export and transportation of Dendrobium produced in Thailand was blocked, resulting in the current Beijing market selling products with a wholesale price of 10 yuan per package to 13 yuan to 15 yuan, which is relatively easy to sell.

Heavy rainfall in Guangdong has damaged chrysanthemum production, so the price of chrysanthemum in Guangzhou market remains high in June, with wholesale prices of six or seven yuan for white and yellow chrysanthemum and 2.5 yuan for small chrysanthemum. Due to the small amount of flowers on Oncidium in July, the wholesale price is higher in the market, with grade A products ranging from 35 yuan to 40 yuan per pack, grade B products ranging from 25 yuan to 30 yuan per pack, and grade C products costing about 20 yuan per pack. Similar to the Beijing market, due to Thailand's export restrictions, there are few Dendrobium orchids in Guangzhou market, with a wholesale price of 20 yuan per pack. Affected by the high temperature, Gladiolus is out of stock on the market at present. In addition, in the off-season, the price of cut Anthurium andraeanum has dropped, but it is also higher than the same period last year, mainly due to the decline in production of cut Anthurium andraeanum in Hainan, Guangdong and other areas affected by typhoons. The wholesale price of high-quality products has risen to 5 yuan from about 3 yuan last year, and the wholesale price of general quality products can be sold at 3 or 4 yuan each. The wholesale price of other colors is about 10 yuan each.

The prices of cut flowers such as Anthurium andraeanum and Oncidium in Kunming market are generally on the high side compared with previous years, and the wholesale price of Anthurium andraeanum sold for one or two yuan in previous years is three or four yuan this year. Green palm and pink palm also performed well, with the wholesale price of green palm at seven or eight yuan and pink palm at four or five yuan each. Oncidium and Gladiolus are less on the market and their prices are higher than the same period last year. The wholesale price of Oncidium is 35 yuan to 45 yuan per pack. The wholesale price of general quality gladiolus is about 0.7 yuan each, while good quality products can be sold for 1.3 yuan each. Dendrobium, Phalaenopsis and Cymbidium cut flowers are rarely seen in the market at present.

Commentator: Beijing Laitai fresh cut flower wholesaler Yao Jiayong

Kunming Dounan Flower Market wholesaler Li Qimeng Guangzhou Huihuang Flower Huang Yongfu