What is the cause of orchid anthracnose? What should I do with it?

Recently, some florist friends consulted backstage: what is the disease of black spots on orchid leaves? What should I do with it? In fact, this is one of the common diseases of orchids, orchid anthracnose, so how to prevent and cure orchid anthracnose? How can the beautiful orchid regain its former elegance?

1. Occurrence regularity of orchid anthracnose.

Orchid anthracnose is a fungus-induced disease, which usually occurs in high temperature season, especially when it is sunny and rainy, the cultivation density is high, the plant material is too fine, and it can not be ventilated. (among the many orchid varieties, Cymbidium has the highest infection rate.)

II. Harmful symptoms of orchid anthracnose

When the occurrence of orchid anthracnose is mild, spots of different sizes appear on the leaves, so that its ornamental value decreases; when the occurrence is serious, the leaves die, the orchid plants do not blossom and lose their ornamental value. When it occurs in the first half of the year, it mainly harms the old leaves and the tender leaves in the second half of the year.

III. Prevention and control measures of orchid anthracnose

For orchid anthracnose should be based on prevention, pay attention to the use of coarse-grained plants, reasonable watering, fertilization, and ventilation, frequent spraying of chlorothalonil, charcoal and other drugs, prevention.

1. When the disease is mild, if a disease occurs in the diseased leaves, the diseased plants can be isolated from other orchids. If the disease is mild and has fewer disease spots, the diseased leaves can be cut off so as not to cause infection.

Cut off diseased leaves must be burned in time, so as not to cause infection. Do not be unwilling, otherwise the whole plant will be infected and regret.

After cutting off the diseased leaves, spray the medicine in time, 50% anthrax powder has special effect on anthrax, once every seven days, three times continuously, the control effect is more than 90%, generally can effectively control the harm of the disease, can control the disease spot no longer expand, and kill the disease germs.

two。 When the disease is serious, you can consider changing the basin when the disease is more serious, if it is a valuable variety, you can consider changing the basin, take out the diseased plant from the orchid basin, cut off the diseased roots and leaves, put them into potassium permanganate solution for disinfection, and after soaking for a period of time, dry the roots into chalky white, replace the plant material, and change the new basin. After watering, slow down the seedlings. After changing the basin, continue to spray disease prevention drugs, once a week, three times in a row, generally on it.

3. Note, orchid anthracnose this disease, relatively speaking, or relatively easy to treat, remind, after the disease, you can spray some high-quality rice vinegar, auxiliary treatment, but strictly prohibit spraying water, so as not to expand the infection.

The above is all about the prevention and control of orchid anthracnose. Do you have any other better additions? Welcome to leave a message and communicate with each other. Finally, I wish you all can grow beautiful orchids!

White orchid anthracnose Magnolia (scientific name: Michelia alba DC.): evergreen tree, up to 17 m high, with broad umbrella-shaped crown; DBH 30 cm; bark gray; scented branches and leaves; shoots and buds densely yellowish white puberulent, hairs gradually falling off when old. Leaves thinly leathery, long elliptic or lanceolate-elliptic, glabrous above, sparsely puberulent below, reticulate veins on both sides obvious when dry. Flowers white, extremely fragrant; tepals 10, lanceolate; pistil carpels numerous, forming sparse aggregate fruit with receptacle extension at maturity; scarlet when ripe. Flowering from April to September, blooming in summer, usually sterile.

White orchid anthracnose [symptom] the disease is mainly harmful to leaves. At the initial stage of the disease, there are chlorotic spots on the leaf surface and gradually expand, forming round or irregular disease spots, dark brown at the edge, light color in the central part, and small black spots on it. If the disease spot occurs at the leaf edge, the leaf will be slightly distorted. When the disease is serious, the disease spots are connected to each other into large disease spots, causing the whole leaf to scorch and fall off. [pathogen and pathogenesis] the pathogen was COlletotriChum gloesporioides. The pathogen overwintered in the diseased body and spread by wind and rain from June to July of the following year. Rain Water occurs when the air is moist and the ventilation is poor, and the peak period is from July to September. The disease is more serious in the young trees of white orchids. [control methods] the distance between ① plants should not be too close. To facilitate ventilation and light transmission. Cut off the diseased branches and leaves in time, destroy them centrally, reduce the infection source, spray 70% anthrax Fumei 500x solution and 65% Dessen zinc wettable powder liquid at the initial stage of ②. Or 1V / L / 1L Bordeaux solution, once every 10 days. The effect of spraying three times in a row is better. Prevention and control of orchid anthracnose

The most common disease of orchids is anthracnose. The disease is harmful to orchid leaves and often occurs at the tip and edge of orchid leaves. Leaf disease, the initial round or oval black spot, and then gradually expanded, in the later stage, the center of the spot was light brown or the edge of the dark brown or dark brown, the boundary between the disease and the healthy part was clear. The expansion of the disease spot is often limited by the leaf vein, and the disease spot on the leaf tip is often triangular, spreading downward from the leaf tip. The disease spot on the edge of the leaf is often semicircular, the disease part is brittle, and sometimes ruptured longitudinally. The size of disease spot varies with the width of orchid leaves.

The disease mainly harms many kinds of orchids, such as Chunlan, Jianlan, Cymbidium and so on. A large number of diseased spots appeared in the leaves of the diseased plants, which affected the growth and ornamental.

The pathogen of the disease is a semi-known fungus that overwinters with mycelium in the host residue or soil. The next spring produced conidia, spread by wind and rain, invaded from the wounds of orchid leaves, and spread repeatedly in the same way, causing damage. The disease was prevalent from July to September.

Prevention and control methods 1. Cut off the diseased leaves and burn them in time. 2. To strengthen the cultivation management and keep the orchid cultivation environment ventilated and transparent, watering should be injected from the edge of the flowerpot to avoid leaf watering.

3. At the initial stage of the disease, 50% carbendazim wettable powder is sprayed 2 to 3 times with 50% carbendazim wettable powder, or 1000 times thiophanate methyl, or equivalent Bordeaux solution.

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