The black spot of orchids, how to prevent and control the black spot of orchids

Orchid is a kind of plant that "looks at the leaves better than the flowers". When an orchid is infected with black spot disease, the best way is to remove its diseased leaves, but this will reduce the ornamental and economic value of orchids (especially precious species). The following three methods can be effective** orchid black spot disease and do not need to remove the diseased leaves.

1. Gentian purple method After finding that the orchid suffers from black spot disease, it should be immediately wiped with gentian purple (the coating area slightly exceeds the lesion), the plaque will no longer expand, and it can be healed within a few days, so that the leaves can be preserved, and it is equally effective if the saturated solution of potassium permanganate is not used without gentian violet.

2. Spraying edible vinegar on the foliage of flowers can eliminate black spot, powdery mildew, and leaf spot, and can also prevent and control the yellowing of camellia and rhododendron.

3. Leek method Soak the leek leaves in clean water for 24 hours, generally the ratio of leeks to water is 1:10. Watering the flowers with water soaked in leeks can prevent black spot and powdery mildew, and can reduce the disease on infected flowers.

Spraying the leaves of diseased flowers with water from soaked leeks can also be a symptom.

Orchid black spot disease, also known as anthrax, is caused by a viral infection. Orchids are highly susceptible to disease in the case of pest bites, sun burn, overly dense planting, and poor ventilation, especially in autumn.

At the beginning of the disease, the leaf surface of the orchid leaf appears irregular concave brown half-point, and then the spot area expands or appears swirl, or the shape is round. When the disease is severe, the whole leaf withers and falls due to the disease, which reduces the appreciation value and economic value of the orchid.

To prevent and treat this disease, the main thing is to keep the environment of orchid cultivation ventilated, and the humidity should not be too large. During the illness, special care should be taken not to spray the leaves of the bluegrass, that is, in particularly dry weather. For fine spots, carbendazim, methyl spray can be taken.

For large spots and large spots, in order to preserve the whole leaf, you can apply purple potion (gentian violet) to the diseased area, and the spots will no longer spread. Wait for the next day to wash off the application solution.

What should I do if my orchid has black spot and how to prevent it?

Prevention and control of orchid black spot disease:

1. Strengthen quarantine, pay special attention to the quarantine of the place of origin, choose new soil without germs to plant orchids, and use formaldehyde liquid for soil disinfection when using old soil. Choose disease-free seedlings to control the spread of diseases. After planting, spray the soil surface with a new high-lipid film, which can protect moisture and waterproof evaporation, protect against sunlight and drought, prevent soil compaction, suffocate and isolate the source of diseases and insects, and protect the seedlings to thrive.

2. Maintain a ventilated and light-permeable growth environment, and shade in summer and autumn. Reasonable watering and fertilization, and spraying new high-fat film to protect moisture and fertilizer. Remove diseased leaves and fallen leaves in time, cut off the lesions in the upper and middle parts of the leaves, and burn them intensively.

Spraying the flowers in a timely manner after flowering can promote strong buds, hypertrophic petals, bright flower color, rich floral fragrance and prolonged flowering period.

3. Spray a dose of Bordeaux solution plus a new high-fat film 2 times before the onset of the disease, once every 10 15 days. In the onset period, targeted agents and new high-lipid membranes are used for prevention and treatment. When spraying, pay attention to the front and back of the blade should be evenly sprayed.

7 1 time in 10 days, many times in a row, the fungicide is used alternately, the effect is better.

The orchid was covered with black spots, but it was infected with anthrax.

Solution: After the plant is infected with the disease, the pathogen will overwinter on the diseased leaves of the residual plant in the form of hyphae, so once the diseased plant is found, it should be destroyed immediately.

2. Strengthen maintenance, in daily maintenance, pay attention to ventilation and light transmission, and planting should not be too dense. Pay attention to the indoor temperature and don't get too stuffy.

3.During the rainy season, it is necessary to avoid heavy rain and frost damage.

4.Timely spraying of pesticides for prevention and control, especially in the big season, spray 50% carbendazim wettable powder 500 times or 50% tobuzin wettable powder 500 times every 10 days or so, spray 3 4 times can be effective.

Extended information: Anthrax is a common disease of orchids that damages the leaves of orchids, often occurring at the tips and edges of orchid leaves. The leaf onset is initially round or oval black spot, and then gradually enlarged, and then the center of the spot is light brown or the edge is dark brown or dark brown, and the boundary between the diseased part and the healthy part is clear. The spread of lesions is often limited by the veins of the leaf, and the lesions at the tip of the leaf tend to be triangular in shape and spread downward from the tip of the leaf.

Marginal lesions are often semicircular, brittle, and sometimes fractured longitudinally. The size of the lesion varies depending on the width of the orchid's leaves.

Orchid black spot disease** is as follows:

1. When an orchid has black spot disease, the diseased leaves should be cut off first, isolated from other healthy orchids, treated with sterilization and sterilization, and cultivated separately to facilitate observation and care to avoid infection to healthy orchids. Orchid black spot disease, also known as anthracnose and black spot, is a fungal disease, which mainly harms the leaves and stems of orchids, makes orchid leaf tissues black and necrotic, affects the healthy growth of orchids, and reduces the ornamental nature of orchids.

2. Although the black spot disease of the orchid will not cause the death of the orchid immediately, if the germs on the leaves are not cleaned up in time, they will slowly spread and become larger, which will make the leaves of the orchid full of black spots and black spots of different sizes. When the disease is very severe, the leaves will die, affecting the emergence and flowering of orchids.

3. The reason for the occurrence of black spot disease is that the orchid is infected with germs on the one hand, and on the other hand, the environment is not ideal, which leads to the mass reproduction of germs.

4. If the orchid has black spot disease, the situation is not serious, and the leaf should be discarded away from the place away from the orchid.

Then dilute 2000 times with carbendazim or methyl tobuzine with water, spray the leaves of the orchid and water the planting material of the orchid, use it every 7-10 days to kill the germs in the leaves and pots, and defend until the black spots on the orchid leaves stop expanding and do not produce new black spots.

5. After using the drug, it is found that the lesions are still expanding rapidly, indicating that the environment is not ideal, and the planting material in the pot should be checked whether it is too wet, if it is too wet, it is necessary to replace the planting material with better drainage or reduce the watering frequency.

It is also necessary to check whether the ventilation of the environment is appropriate, change the place of placement or open doors, windows and fans to ventilate if the ventilation is not smooth, and pay attention not to expose the orchid to the sun, the high heat and humidity in the sunning pot, the germs multiply, and the black is easy to produce black spots.

Orchid black spot disease needs to be moved to a ventilated environment and treated with a drug**.

When raising orchids in a poorly ventilated environment, black spots are easy to appear on the leaves, so they need to be moved into a well-ventilated environment immediately, and the temperature of the place needs to be kept between 15 and 30, so that the phenomenon of black spots on the leaves of orchids can be well improved.

If the orchid is attacked by pests and diseases, the leaves will also become yellow or black, such as infected with anthracnose, thrips and other pests and diseases, the nutrients of the plant will be absorbed by them, and gradually form black spots.

Tips to prevent dark spots in orchids

If it is placed in a shady environment during the growth stage, and the lack of light for a long time, the leaves of the plant will appear black spots, and it is necessary to add some light to it appropriately, which can greatly improve the phenomenon of black spots on the leaves of orchids.

Orchid for the growth environment requirements is relatively high, if the phenomenon of water accumulation occurs daily, it will affect the normal absorption of nutrients by the leaves, and gradually will form black spots, at this time you can add some loose medium to the garden soil, which can increase the drainage capacity of the soil in Qingzheng, and then reduce the number of watering times, so that you can also prevent and control the black spots of orchids.

After the black spots grow on the orchid, the leaves with black spots need to be pruned off in time and the cut leaves should be destroyed. After that, carbendazim solution should be sprayed on the wound for sterilization and disinfection. The appearance of dark spots on bluegrass may be caused by too much light, so it needs to be moved to a place with soft light for maintenance.

It can also be caused by over-fertilization, in which case it is necessary to water the potting soil to reduce the concentration of fertilizer.

The most effective way to remove dark spots from bluegrass.

When black spots are found on the orchid, the leaves with black spots should be removed in time and the cut leaves should be treated. After that, carbendazim solution should be applied to the wound of the orchid for sterilization and disinfection. If the area of the black spots on the bluegrass is not large, you can use a cotton swab dipped in some methyl tobuzine solution to puncture the black spots, and then transfer them to a ventilated environment for maintenance.

The appearance of dark spots on the leaves of bluegrass may be caused by too much light, so when caring for bluegrass, it is necessary to store it in a ventilated environment and avoid direct sunlight. In summer, when the light is too strong, you can build a shade net on the bluegrass to weaken the intensity of the light.

Lack of water can also lead to dark spots on the orchid, so you need to water the orchid in time until water comes out from the bottom of the pot. Pay attention to the watering should not let the water contact the flower buds of the orchid grass to avoid the rotting condition of the flower buds.

Excessive fertilization can also cause burns to the roots of the orchid, so that the leaves cannot absorb nutrients and appear black, so it is necessary to water the soil once to reduce the concentration of fertilizer in the soil, and then turn the soil to allow the excess fertilizer to flow out of the pot.

In summer, the leaves of orchids are prone to some black wheel regrets, so how to prevent it? 1.Mancozeb: Many people choose mancozeb for spraying.

Mancozeb is actually only a protective type, which can destroy external germs, but cannot destroy internal germs. Once the method is not right at this time, it will be in vain. Even longer and more, because the black spot disease already has germs in the body.

At this time, we must prescribe the right wax mold medicine and eliminate it once and for all. 2.The method of killing benzazolate is also very simple.

Generally, if it is severe, cut off the serious leaves first. After cutting, it is fully sterilized with benzazolate and sprayed once. When spraying, spray all aspects of the front digging, including the walls of the planting pot.

We spray once or twice, and its leaves will be clean and the new leaves that grow will no longer have black spots. Therefore, if you plant orchids, at this time, if we are going to maintain and ** black spot disease, we must remember this skill well, and do not choose mancozeb, because mancozeb is a topical fungicide, not an endogenous type.

Orchid leaf black spots, is the cause of black spot disease, at this time there will be reddish-brown or purple-brown spots on the leaf surface, with the aggravation of the disease continues to expand to dark black, and finally cause the leaves to wither yellow and fall off, after finding that the orchid is diseased, it is necessary to remove the diseased leaves in time, and disinfect with carbendazim, and finally place it in a ventilated environment for maintenance, so that the orchid can recover health.

When black spots are found on orchid leaves, it is a disease called black spot. In the early stage of black spot disease, there will be a reddish-brown or purple-brown dot on the leaf surface, which will expand to dark black spots as the disease increases, and finally cause the leaf to wither and wither in severe cases.

For the occurrence of orchid black spot disease, it is actually relatively easy to solve. First of all, when the disease is relatively mild, some diseased leaves are removed in time, and then disinfected with a multi-spirit bacterial solution, and finally placed in a relatively ventilated environment, so that the leaves will gradually improve after a period of time. When the occurrence of black spot disease is more serious, it is necessary to spray it with drugs in time, for example, the drugs can be sprayed with Bordeaux liquid or Tobuzin, sterilizer, etc., which can be sprayed twice a week until the disease is completely eliminated.

In order to prevent the phenomenon of orchid black spot disease, it is necessary to keep enough light in the usual maintenance, and pay attention not to be in the shade or exposure to the sun for a long time. Keep it warm all year round, and be careful to avoid low and high temperatures. Watering and fertilizing must be appropriate, and care should not appear too much or too little.