White mold on the trunk of a magnolia tree? What to do if there are a lot of white mold spots on the

It may be powdery mildew.

Precautions for the maintenance of magnolia.

1. Soil. It prefers to grow in deep, fertile, well-drained and slightly acidic or neutral soils, and is not tolerant to salinity. If it wants to thrive, it needs to provide a suitable soil environment.

2. Watering. Its root system is fleshy and does not tolerate stagnant water. However, water is also inseparable during the growing season, so it is necessary to water frequently to make the soil moister.

When the temperature drops down in autumn, reduce the amount of water to help it survive the winter. In winter, it is recommended to stop the water and water it once when it is dry.

3. Illumination. Magnolia is very fond of light, and should be placed in the light during the breeding period, only when the light is enough can the branches flourish and bloom normally. If you don't get sunlight for a long time, it will be difficult to bloom and it will be easy to grow poorly.

Fourth, temperature. Magnolia tree.

It is sensitive to temperature, and if the temperature is high, the plant will bloom early. It has strong cold resistance and can tolerate low temperature milk at minus 20 degrees Celsius.

So don't worry too much about winter. However, in cold areas, it is still recommended to take cold protection measures, otherwise it will affect the growth of the next year.

5. Nutrients. Magnolia nutrient supplement, you can choose the fertile leaf water-soluble fertilizer series.

6. Precautions.

Magnolia trees are susceptible to leaf spot disease, anthracnose.

Diseases and pests such as red spiders and longhorn beetles, once found, should be treated and treated in time, spraying drugs as soon as possible to avoid infecting healthy branches and avoiding deterioration.

Powdery mildew occurs in leaves, young stems, flower stalks, flower buds, petals and other parts, and is yellow-green irregular spots at the initial stage, with inconspicuous edges. The lesion then expands, and powdery spots develop on the surface, and eventually numerous black spots grow there. The infected area turns gray, covering its surface in patches, with unclear edges and a stained white or pale grayish-white color.

When the damage is severe, the leaves shrink and become smaller, the tender tips are twisted and deformed, and the flower buds do not open.

Autonomous drugs can be prevented:

1. Green onion liquid: take 50 grams of green onions and mash them into a puree, add 50 grams of water, soak them for 12 hours, spray them with filtrate after filtration, and spray them many times a day, for 3 or 4 days, which can cure powdery mildew.

2. Rice vinegar: Rice vinegar is rich in organic acids, which has a good inhibitory effect on bacteria. Spray the leaf surface with a rice vinegar solution diluted 150 200 times, spray 1 time every 7 days or so, and spray 3 4 times in a row, which can prevent and control powdery mildew, black spot, downy mildew, etc.

3. Baking soda solution: take 5 grams of baking soda (also known as sodium bicarbonate), dissolve it with a small amount of alcohol, and then add about 1000 grams of water to prepare a concentrated solution and spray the plants to prevent and control powdery mildew.

Hello, it may be powdery mildew, the powdery mildew of the magnolia tree first grows small round powdery mold spots on the front or back of the lower leaves, gradually expanding, thick, and soon connected into a piece. In the later stage of the disease, the whole leaf is covered with white powder, and the mycelium turns gray-white after aging, and finally the leaf is yellow-brown and dry. The stems and petioles also produce leaf-like lesions, dense powdery mildew spots.

In autumn, sometimes small yellowish-brown spots are produced on the sick class, which later turn black, that is, the ascomycetes of the sexual generation. The leaves of this disease are covered with white powder, and the lower epidermis of the mold layer remains green at the beginning of the disease, which is easy to distinguish from other leaf diseases.

When the disease is in full bloom, it can be sprayed with 15% powder rust 1000 times, 2% antimycosin water 200 times, and 10% polyantimycin 1000 to 1500 times. Repeated use of traditional medicines reduces the effect of antibodies produced by germs, so it is recommended to use them alternately. In addition, you can also use 1000 times of liquor (alcohol content 35%), spray once every 3 to 6 days, spray 3 to 6 times continuously, and rinse the leaves until there is no white powder.

White orchid leaves develop powdery mildew due to rain or high humidity. Remove the tips and leaves of the susceptible shoots and leaves in time.

There is some white powder attached to the powdery mildew leaves, which appears on the back of the leaves at first, gradually expands to the front of the leaves and stems, flower buds, and then the back of the leaves that grow white powder also appears purplish-red spots with large or small spots.

This disease is more likely to occur in unventilated rooms or when white orchids are weak. Strengthen management, reasonable irrigation and fertilization, and enhance tree resistance. At the same time, it enhances the exposure to sunlight.

Powdery mildew: spray sterilization with diluted carbendazim and methylamine solution.

Pay attention to the main points when planting white orchid trees.

1. White orchids like warmth and humidity, should be well ventilated, have sufficient sunshine, be afraid of cold, avoid moisture, do not like shade, and are not resistant to sunburn. 1. From March to April every year, move the pots and jars planted with white orchids out of the outdoors and place them in a sunny place.

2. In summer, when the temperature is high, you should choose a shade net or build a simple shade canopy as appropriate, so that the white orchid can not only shine on the morning sun, but also avoid the strong light in the summer afternoon (so as not to burn the branches and leaves due to the sun).

3. Whenever there is continuous drizzle in autumn or heavy rain in summer, pots and tanks should be placed in a sheltered place in advance to avoid root rot due to excessive water accumulation. 4. In winter, it should be placed indoors where sunlight can reach and has good sealing. In order to prevent frostbite on the roots, the pots and jars where white orchids are planted should also be wrapped with plastic film.

4 is not cold-resistant, except for South China, other areas should be maintained in winter, the minimum room temperature should be maintained above 5, and the time to go out of the room is appropriate from Qingming to Guyu.

White Orchid Tree - Sogou Encyclopedia.

There are many reasons why magnolia leaves turn yellow, and if it is caused by overwatering, it needs to be drained in time to increase the aeration of the soil. If it is caused by pests and diseases, it is necessary to prescribe the right medicine and treat it in time. If the light is too strong, the plant needs to be moved to the shade.

Next, I will tell you about the solution to the yellowing of magnolia leaves.

1.Replace the potting soil.

Magnolia has high soil requirements, so it is best to choose sandy soil with good drainage and slightly acidic for planting. If the soil is chosen to cause root rot, it will cause the plant to have yellowing of its leaves. It is necessary to change the potting soil in time, disinfect the roots before changing the potting, and cut off the rotten roots before repotting.

2.Shading treatment.

Magnolia likes light, but avoid direct sunlight, otherwise it will cause the water of the branches and leaves to evaporate too quickly. The yellow leaves can be cut off first, and the plants can be moved to the shade for maintenance. After the plants slowly recover and recover, they will be moved to a soft and light place for maintenance.

3.Water properly.

Magnolia likes moisture, if the potting soil is too dry, it will affect the photosynthesis of the leaves, and it is easy to cause the branches and leaves to wither and yellow. It needs to be watered in time to keep the potting soil moist. If the leaves are yellowing due to overwatering, and it is necessary to drain the water in time, you can use the rooting agent to promote the new roots of magnolia.

4.Increase fertilization.

Magnolia likes fertilizer, if too little fertilizer will lead to malnutrition of the plant, it should be fertilized in time after the plant is potted. Compound fertilizer is mainly applied during the flowering period, nitrogen fertilizer can be applied after flowering, and phosphorus and potassium fertilizer can be appropriately applied at high temperature in summer.

5.Disease prevention.

Common diseases of white orchid include yellow leaf disease and anthracnose, and the diseased roots should be cut off in time to prevent the virus from continuing to invade the plants, and can be protected by spraying ferrous sulfate solution.

6.Precautions.

There is also a condition that the yellowing of magnolia leaves is caused by the normal aging of the leaves, which is a normal phenomenon and does not need to be treated in any way.