How to prevent and control camellia brown spot disease? Brown spots appear on the tips of camellia l

1. Burn the diseased leaves and fallen leaves before winter, and then spray a stone sulfur mixture, and then move it indoors for wintering.

2. Reasonable fertilization to promote the vigorous growth of camellia plants and enhance resistance. Try to avoid damaging the camellia flowers and leaves, and at the same time protect against wind, rain, and sun burn, and do not water the plants.

3. In the early stage of the disease, prochloraz emulsifiable concentrate, polymanganese-zinc wettable powder and other agents can be used, which can be used once every 10 days for 2 or 3 times. During the bud formation period, spraying chlorothalonil 600 800 times had the best preventive effect.

The above suggestions are for your reference.

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The red spider that harms the cherry is mostly the hawthorn red spider, also known as the hawthorn leaf mite, the female adult mite is dark red, and the body length is millimeters. The insect sucks the sap on the back of the leaf with adult and mites, and the leaves initially appear greenish spots, and then expand into patches, and the leaves are scorched and fall off when they are severe, thus affecting the growth of fruit trees and the formation of flower buds in the following year. Hawthorn spider occurs in 5 to 10 generations a year, fertilizing female adult mites to overwinter in the cracks of branches and under rough skin.

In the spring of the following year, the cherry buds swelled out of the stinging activity, and after the buds bloomed, they were transferred to the buds for damage, and the leaves were damaged after the leaves, and then the eggs were laid, and the eggs hatched after flowering, and the first generation of larvae appeared. Spider mites like high temperatures and dryness, so the occurrence of June and July is the most serious, after entering the rainy season, the number gradually declines, and after September the adult mites mate and overwinter.

For the prevention and control of spiders, focus on two key control periods, that is, the sting period of overwintering adults and the hatching period of the first generation of eggs after flowering, and select high-efficiency and low-toxicity control agents. At the bud germination stage, spray the branches with 50 100 times of engine oil emulsion or 3 5 Baumé stone sulfur mixture; After flowering, spray 2000 times of 20% mite dead net suspension agent; 6. During the large occurrence period in July, use 2000 times of 15% scavenging mite net emulsifiable concentrate or 2000 times of 73% gram mite emulsifiable concentrate or 4000 times of avermectin emulsifiable concentrate.

Brown spot disease, also known as crustacean ulcer, is caused by bacterial parasitic infections of Vibrio, Aeromonas, spirochetes and Flavobacterium.

Symptoms] There are black-brown or black spot-like ulcers on the carapace and appendages on the body surface of the diseased shrimp, the edge of the spot is light, the middle color is dark, the edge of the ulcer is white, the ** depression of the ulcer can erode to the tissue under the carapace in severe cases; In severe cases, it rapidly expands into dark spots, and then dies one after another. Diseased shrimp have black ulcer spots on their carapace and appendages.

How many years have you been planting? Isn't it a few years since the soil has been changed?

That is, the soil is no longer good, and the soil should be replaced.

Go find some humus and some red soil and sand.

After mixing well, change the soil for it, so that it may be better.

Camellia leaves appear black spots, solve these causes in time, the leaf color is dark green, and the flower color is gorgeous.

Where you can buy flowers, you can buy them.

What drugs can be used to **Camellia leaf black spot disease?

1.Symptoms and causes of camellia leaf black spot disease.

Camellia leaf black spot disease, also known as camellia leaf spotted disease, is a type of tumor charcoal disease caused by a fungus. Symptoms include the appearance of a non-sizing appearance on the leaves of the camellia.

1. Black spots with blackened edges, brown or grayish-black, and irregular spots. If it is not prevented in time, it will lead to camellia wilting, leaf falling, affecting the opening of flowers, and in severe cases, it will lead to the death of camellia. Camellia leaf black spot disease is mainly caused by the comprehensive influence of water, soil, pathogenic bacteria, climate, pathology and other factors.

2.Methods to prevent black spot disease in camellia leaves.

In order to avoid the occurrence and spread of camellia leaf black spot disease, people need to take the following measures:

Select camellia varieties with strong disease resistance, and require seedlings and soil to be free of pathogens;

Strengthen fertilization and drainage to ensure good soil drainage;

Routinely clean up fallen leaves and other plant waste dropped by camellia to ensure the timely disposal of domestic garbage in the garden.

3.**Medications for camellia leaf black spot disease.

If there is black spot disease on camellia leaves, it needs to be carried out in time**. **Camellia leaf black spot disease, the right drug can achieve better results. The main drugs currently used are:

Phenol. Phenol is a broad-spectrum fungicide that has good control effect on a variety of fungi and bacteria. Phenol can inhibit the development of black spot disease in camellia leaves and reduce the harm of the disease to camellia. Add phenol to an appropriate amount of water, evenly spray on the camellia leaves that have appeared black spots, spray once every 7 days, and spray 2 times in a row.

Calcium hydroxide. Calcium hydroxide is an alkaline substance that has the effects of sterilization and disinfection. Camellia with Camellia leaf black spot disease can be treated with calcium hydroxide**. Add calcium hydroxide powder to an appropriate amount of water, spray evenly on the leaf surface, spray once every 10 days, and spray 3 times in a row.

4.Summary.

Camellia leaf black spot is a common disease among flower diseases, **Camellia leaf black spot disease needs to take a scientific approach. The best way to prevent and improve camellia leaf black spot disease is to adopt comprehensive control methods, including strengthening cultivation management, timely cleaning of waste, and selection of appropriate pesticides. In the selection of drugs, chemical agents such as phenol and calcium hydroxide can be used, which have good prevention and control effects.

However, when using chemicals, the concentration of the chemicals should be controlled within an appropriate range to avoid secondary harm to flowers.

Black spots on the leaves of camellia may be leaf spot, which is a common camellia disease, in the initial stage of the disease, there will be black-brown spots on the leaves, and over time, these spots will slowly expand, so that the leaves appear large gray-brown patches, and some will be gray-white. There are many small black spots on the black-brown patches, which eventually cause the leaves to wilt and wither.

The reason why camellia can get leaf spot disease is mostly because the air is too humid and hot, not ventilated, or caused by too much watering, and the spores of the fungus infect the plants through various ways and spread wildly, so that the camellia suffers from disease spots.

Method: If you have this disease, you must remember not to get water on its leaves, otherwise it will accelerate the aggravation of the disease. Before overwintering, all infected leaves are removed and burned, and then sprayed with stone sulfur mixture**.

Take care to protect the leaves from sunburn and frost. In addition, you can regularly spray the liquid medicine for prevention and nutrient supplementation, which can reduce the chance of camellia disease.

If the camellia has bituminous coal disease, it will also appear black spots on the surface of the leaves. These lesions are grayish-brown at first, but gradually turn black and widen in size.

The disease is generally a fungal infection induced by aphids and scale insects in a hot, humid and poorly ventilated environment. The higher the degree of humidity and heat in the environment, the faster and faster the lesions spread, and the black lesions that appear after infection will destroy photosynthesis, affect the healthy growth of plants, and cause great harm to plants.

**Method: First of all, it is necessary to prevent it from the source, pay attention to the air circulation and sufficient light in the plant growth environment, and wipe the diseased leaves with water to remove mildew from the surface of the leaves. However, the cause of the disease is pests, so it is necessary to start from the source, and all the aphids and scale insects that induce disease should be killed, and they should be sprayed frequently to prevent insecticide in ordinary times to maintain the healthy growth of camellia.