What are the causes, harmful symptoms, and prevention and control measures of cucumber powdery milde

Cucumber powdery mildew is a fungal disease, which is one of the emerging diseases in the production of melon crops such as cucumbers in plastic greenhouses or greenhouses. The incidence has been increasing year by year. In November 2001, it occurred for the first time on a small number of cucumbers in a small number of sheds in Heying Village, Xiaolongma Township, Yongnian County, and the rate of diseased cucumbers in the sheds was diseased.

Planting control. 1. Seed disinfection: soak seeds with 50 times dilution of 25% carbendazim wettable powder for 30 minutes, pour the liquid and sow the seeds the next day after drying.

2. High furrow mulch film cultivation: high furrow mulch film cultivation can be implemented in protected or open land, or straw or wheat straw can be laid on the furrow surface. It is best to raise cucumbers in the shed in the autumn shed.

3. Ditch irrigation under the membrane: moderate watering and timely removal of excessive moisture in the air to control the onset of the disease.

4. Strengthen management: cucumbers cultivated in sheds should be moderately densely planted, pruned and tied in time, and attention should be paid to ventilation and light transmission. Properly control watering in the early stage of cucumber growth in spring greenhouses, carry out ventilation at night and early morning, and choose non-dripping film to prevent dripping on the roof of the shed.

During the onset of the disease, farm work such as picking melons and tying vines should be carried out after the dew disappears. Strengthen field drainage in the rainy season and top dressing in time. [1]

Pharmacological prevention. Pesticide control: the focus is on removing the diseased leaves before and after the rain at the seedling stage and at the beginning of the disease, and then applying the drug every 5-10 days, 3-4 times in a row.

The agent can be diluted 500 times of 50% carbendazim wettable powder, or 50% tobuzin wettable powder 500 times diluted, or chlorothalonil and carbendazim, or chlorothalonil and tobuzine 1:1:1000 mixture each.

At the beginning of the disease, fumigation chlorothalonil aerosol agent, or spraying 10% chlorothalonil dust agent, kilograms per 1000 square meters. [1]

The cause of the disease is due to the destruction of the pH level of the soil of the cucumber. Symptoms may be red and pink spots or moldy fungus. There are also symptoms of leaf loss and yellowing.

The control measure is to spray some pesticides, but also to spray some professional insecticide reagents. It is also necessary to cut off some of the yellowed leaves.

The cause of the disease is high impact temperature, insufficient sunlight, poor ventilation and noisy greenhouses, or cucumber powdery mildew is prone to occur in greenhouses, the suitable temperature for the development of pathogens is 28 30 degrees, and the relative humidity is higher than 85% is the most susceptible to disease; Its symptoms are: dark green, round or oval, irregular light brown lesions on the leaves infected with powdery mildew; The prevention and control measures should be intensively tied to the vines in a timely manner, pruned in time, ventilated in time, irrigated reasonably, and prevented with pesticides.

It may be infected by germs, it may be rain, it may be that the humidity is too high, it may be that the sun is not enough, it may be that the ventilation is not good. There will be some water stains on the edges of the leaves, and they will crack easily, sometimes mold will appear, and eventually the leaves will rot. You can spray some pesticides, to cooperate with the irrigation of the panicle, to control the amount of watering, to ventilate in time, but also to remove the problem plants in time.

It may be a lack of water and fertilizer, it may be that the prevention and control work has not been done, it may be that the temperature is relatively low, and there may be pests and diseases; Once this happens, the cucumber yield will be greatly reduced, and the cucumber leaves will wilt or rot; It is necessary to choose the appropriate mountain medicine according to this disease, pay attention to the volatilization of the medicinal effect, pay attention to the time of use, ensure soil fertilizer, and water and fertilize quietly.

Cucumber powdery mildew is a new disease in greenhouse cucumber production. With the gradual increase of cucumber protected area, cucumber powdery mildew showed an increasing trend year by year. Therefore, in the process of cucumber planting, it is necessary to do a good job in the corresponding prevention and control work to improve the yield and quality of cucumbers.

Cucumbers are a seasonal vegetable in summer, so it is very important to take precautions during the hot summer cucumber cultivation process. First of all, it is necessary to select high-quality seeds that are resistant to heat and humidity, and secondly, we should pay attention to the selection of disease-resistant varieties, and again we should strengthen cultivation management and reduce the occurrence of diseases. What is the effect of the disease on the growth of cucumbers?

Today, we will start with the prevention and control of diseases. Cucumber powdery mildew is mainly manifested as small yellow lesions on the leaves, which make the leaves smaller, shrunken and curled, and in severe cases, there is a dead and feasting of relatives, resulting in the death of the whole plant.

This is a small irregular yellow spot on the leaf and, in severe cases, necrotic spots on the leaf. After the occurrence of cucumber leaf spot, the leaves turn yellow and produce shrunken and dead spots, and finally the cucumber dies, which gradually wilts and affects the normal growth of the plant. What are the prevention and control measures?

1) Apply sufficient base fertilizer: apply about 30 kg of high-quality decomposed organic fertilizer or compound fertilizer per mu. (2) Remove diseased leaves in time

Remove diseased leaves at seedling stage and peak stage, and auspicious jujube to reduce nutrient consumption, prevent plant growth, and improve disease resistance. (3) Timely prevention and control of diseases: For a variety of diseases, carbendazim, clobendan, methyl tobuzin, chlorothalonil, mancozeb, methalene, carbendazim, chlorothalonil, methyl tobuzin, chlorothalonil, Jinggangmycin and other drugs can be mixed.

Spraying control: The prevention and control of carbendazim and other drugs should be carried out in sunny and warm weather. Spraying can be done in combination with foliar spray or watering.

4) Reasonable fertilization: Reasonable fertilization is one of the keys to improving the ability to resist pests and diseases, and insufficient fertilizer is one of the main problems. In terms of fertilization methods, one is to reapply basal fertilizer, and the other is to improve the soil.

You can apply some drugs to cucumbers, you can also spray some insect repellent drugs on cucumbers, you can also control cucumbers, you can spray some pesticides on cucumbers, you can also sprinkle some pesticides on cucumbers, you can fertilize cucumbers, these methods can prevent and control this disease.

First of all, it is necessary to tie the vines at the right time, and should also pay attention to reasonable dense planting, and then after the banquet is rented, it is necessary to pay attention to pruning the branches and leaves in time, and the oak pine should be put in time to ensure the temperature in the greenhouse, and it should also be watered in time.

To prevent cucumber powdery mildew, the seeds should be disinfected first, and then planted with high furrow mulch, watered and topdressed in a timely manner, and drained in time after rain. If the disease occurs, it can be diluted with carbendazim powder or tobuzinco powder, and then sprayed on the land for first treatment.

Cucumbers have such a situation, we should use some agricultural medicine, and secondly, we should also water more and fertilize more, which can be well avoided by the holes, and the branches can also reduce such diseases.

The mycelium of the pathogen overwinters in the soil along with the residues of diseased plants. The following spring, when environmental conditions are suitable, it produces conidia, which spread to cucumber leaves and invade from wounds. After the onset of the disease, a large number of conidia are produced at the site of the disease, and the spores are spread with the help of wind, rain, and irrigation water.

The suitable temperature for bacterial growth is 28-30 degrees, and when the relative humidity is above 85%, disease is most likely to occur. Cucumber pink disease is prone to occur in spring greenhouses or in greenhouses with high temperatures, insufficient sunlight and poor ventilation.

The combination of cucumber and vine can not only make the stem and vine grow consistently, improve the resistance of cucumber, but also improve ventilation and light transmission conditions. A week after the cucumber is planted, erect brackets and slings to tie the vines. Here's how:

Pull a wire in each row at the upper end of the cucumber ridge, fix one end of the rope to the wire, tie the lower end to the hypocotyl of the cucumber, and at the same time lead the vine to the rope. When the faucet is close to the top surface, the vines can fall at any time.

The causative agent of cucumber powdery mildew is mycelium, which will remain in the diseased soil to survive, and if the conditions are right, the hyphae will spread to the leaves and enter through wounds, and the pathogen is usually spread by wind, rain and irrigation water. Cucumber powdery mildew usually occurs in greenhouse cucumbers. In spring, the temperature in the greenhouse is high, the light is insufficient, the ventilation is poor, it is easy to get sick, and cucumbers can also occur, mostly in the summer rainfall and high humidity conditions.

If the temperature is 25-30 ° C and the humidity is more than 85%, it is more likely to get sick.

In the late growth stage of cucumbers, dark green round to oval or irregular light brown lesions appear on the leaves, ranging in size from 1 to 5 cm. When the humidity is high, the edges are soaked with water, and the lesions are thin and easy to break. When high humidity persists for a long time, there will be light orange mold on the lesions, which will spread rapidly, causing the leaves to rot or dry.

The lesion is larger and thinner than anthracnose, dark green in color, and does not produce small black particles, unlike anthracnose and grape wilt, cucumber powdery mildew is a new disease in greenhouse cucumber production.

Of course, I know that the main reason is that cucumbers are grown in greenhouses or greenhouses, and there is not enough light and poor ventilation in spring.

The main manifestation of this powdery mildew is in the cucumber growth after the skin is buried in the fiber stage, its leaves will appear some dark green round lesions, some are light brown lesions, when the humidity is high, the edge will also appear water-immersed, these lesions are relatively thin, easy to break. If the high humidity lasts for a long time, there will be a light orange mold on the lesions, and it will expand rapidly, eventually causing the leaves to rot or dry up. Powdery mildew can have larger spots than anthrax, and this disease is different from cucumber anthracnose and vine blight in that it does not produce small black spots, which is what distinguishes it from other diseases.

Pattern of onset. The powdery mildew bacteria will overwinter with the diseased carcasses in the soil, and in the spring of the second year, when conditions are right, they will produce conidia, which will then spread to the leaves of cucumbers, and enter the cucumbers through wounds. After the disease is known, a large number of conidia will be produced in the affected area, which will spread due to wind, rain and the spread of water during irrigation, resulting in secondary infection.

The most suitable temperature for the development of powdery mildew bacteria is about 25 or 30 degrees, and the relative humidity is higher than 85%, so this disease is most likely to occur in greenhouses or greenhouses with high temperatures, insufficient sunlight and poor ventilation in spring.

The incidence of cucumber powdery mildew is due to the mycelium of the pathogen with the diseased plant Weibi yard residue in the soil which refers to which winter, the spring of the second year, when the environmental conditions are suitable, the conidia are produced, spread to the cucumber leaves, invaded through the wound, and the greenhouse with high temperature, insufficient light and poor ventilation in the spring will also lead to the disease of cucumber.

The conidia of powdery mildew have low stress resistance and short lifespan, and the temperature and humidity of powdery mildew in greenhouses are relatively easy to obtain. Therefore, cucumber powdery mildew occurs more severely in greenhouses. It can also be sprayed with 15% powdered rust powder 1500 2000 times, or 75% chlorothalonil wettable powder 600 times, or 50% dysen ammonium wettable powder 800 1000 times, or 30% DT fungicide 500 times.

The pathogen of powdery mildew of cucumber is monofilamentous powdery mildew and melon monofilamentous shell, which belong to the same genus ascomycetes subphylum fungi, which mainly harm leaves, petioles and stems will also be harmed, and fruits are generally rarely damaged, from seedling stage to harvest stage. In the early stage of powdery mildew, small white and nearly round pink spots appear on the front and back of the leaves and on the young stems, and <>

How do we prevent and **? Based on what I have learned, I will popularize it for everyone. First of all, "powdery mildew" starts from the leaves of cucumbers, due to the influence of temperature, humidity and airflow, there will be a little white spots in the early stage, and then, a little bit of powdery mildew spreading cucumber is a disease that will arise on cucumber leaves, when the onset of cucumber slices, stems, gradually form a pink spot, generally occurs in the cucumber expansion period, although this disease occurs on the leaves or, but the leaves will wither when the leaf powdery mildew is serious.

Cucumber powdery mildew is commonly known as white hair, hanging white ash, is a common disease in the process of cucumber production, commonly occurs in cucumber planting areas around the country, powdery mildew can occur from cucumber seedling stage to harvest period, mainly harms plant leaves, petioles and stems, the disease mainly harms cucumbers, watermelons, melons, pumpkins, bitter gourds and other melon crops, cucumber powdery mildew mainly harms plant leaves, in the early stage of the disease, leaves or leaf backs produce white or pink near-round lesions, in a suitable environment, the lesions gradually expand into a continuous lesion with no obvious edgeIt is covered with a white powdery mold layer, and the diseased leaves are yellow, brittle, curled, and lose photosynthesis.

The typical symptom of cucumber powdery mildew is that the affected area is covered with powdery powder, and in the later stage, it may also scatter yellow-brown to black small spots, that is, the closed capsule shell of the pathogen. Cucumber leaves, petioles and stems can be infected, and this disease mainly harms the leaves, and the fruit suffers less damage. In the early stages of the disease, small white and nearly round stellate pink spots appear on the front or back of the leaves, and in severe cases, they cover the entire leaves.

Cucumber powdery mildew, commonly known as powdery mildew, is caused by the infection of cucumber powdery mildew and cucumber monocystic powdery mildew. In the middle and late stages of growth, the disease is severe, resulting in dry leaves and even early seedling pulling, and the leaves gradually turn yellow, brittle and dry. It generally starts at the bottom lobe and gradually progresses upwards.

Cucumber powdery mildew mainly harms leaves, petioles, stems and vines, but does not harm fruits. At the beginning of the disease, small white spots are produced on the front and back of the leaves, and then they expand and are connected, and they are covered with a layer of white mold. The edges of the white mold are not neat, and then turn grayish-white.

Sometimes small black spots appear on the lesions. The leaves gradually turn yellow, brittle, and dry. It generally starts at the bottom lobe and gradually progresses upwards.