White plaque on an orchid: description with photos, diseases, methods of treatment and advice from gardeners

Many gardeners are faced with the problem of white plaque on an orchid in the growing process. This is an alarming sign that the plant is not all right. Therefore, it is necessary to initially identify the main cause of this symptom and conduct treatment. You should also familiarize yourself with preventive measures that will minimize the likelihood of its reappearance.

Main reasons

If the orchid is covered with a white coating, then its immunity is weakened. Therefore, the sensitivity of the plant to the effects of pests and diseases increases. Improper flower care is the main reason why white plaque appears regularly on orchids.

Provoking factors:

• low or high humidity;
• high or low temperature;
• excessive watering;
• stagnation of water in the pan;
• excessive use of nitrogen fertilizers;
• use of untreated substrate;
• untimely removal of fallen flowers and leaves.

In addition to these provoking factors, a gust of wind through an open window can be a carrier of infection or pest larvae. Therefore, it is important to periodically examine indoor plants and respond in time to the first dangerous signs.

Powdery mildew

This disease is often the reason that white plaque appears on the leaves of the orchid. Initially, a warning sign is observed in small areas, but subsequently, the lesion area increases. This occurs as a result of the activity of powdery mildew mycelium, which rapidly multiplies when favorable conditions are created.

In this case, the white coating on the orchid looks as if the plant was sprinkled with flour. The main reason for the development of powdery mildew is excessive watering and temperature spikes. In the absence of measures to combat the disease, the plant may die.

Mealybug

A characteristic sign of the appearance of this pest are sticky leaves and a white coating on the orchid. This occurs as a result of non-compliance with the conditions of detention and excessive use of nitrogen fertilizing.

The mealybug is covered with protective hairs, and therefore, when it is massed, it looks like cotton wool, which was scattered carelessly.

Initially, the pest is localized in the leaf sinuses, which makes it difficult to combat it, but as it multiplies it moves to the upper roots, leaves and flowers. Subsequently, sticky drops appear, which is a product of his life.

The appearance of a mealybug on a flower indicates a weakened immunity, since a healthy plant is able to independently resist the negative effects of the pest.

What is the danger of white plaque on an orchid?

The worm feeds on the plant’s cell sap, and is also able to inject a special food enzyme into the leaf bite, which leads to a decrease in the vitality of the plant. In addition, sticky plaque secreted by the pest leads to the development of soot fungus, which prevents the full respiration of the leaves and the photosynthesis process. Against this background, the plant becomes pale and loses leaf elasticity. If untreated, the orchid may die.

In the case of powdery mildew, the plant begins to slow down in growth, and flowering may be sparse or completely absent. As the fungal mycelium spreads further, the leaves become lethargic, turn yellow, and subsequently fall off. In the absence of adequate treatment measures, the flower dies over time.

What to do first?

When white plaque appears on an orchid, it is necessary to initially examine not only a diseased plant, but also its neighbors. All flowers on which suspicious signs were detected must be quarantined, rearranged in a secluded place.

In the case of development of powdery mildew, it is necessary to initially limit watering, allow the substrate to dry, and also adjust the temperature of the content.

If a mealybug is detected on the plant, it is necessary to prepare a soap solution at the rate of 40 g of grated product in 200 ml of water. And after its dissolution, wipe the leaves of the plant.

But all these measures can bring a temporary effect, therefore, with severe damage to the leaves, it is necessary to resort to professional preparations that will help cure the flower.

Now consider how to deal with white bloom on orchids in each case, and what means when and how to apply.

Ways to combat fungal disease

To eliminate powdery mildew, it is recommended to use the fungicides "Topaz", "Fitosporin", "Skor". Processing should be carried out by spraying plants from a distance of 20-30 cm. After 1 hour after the procedure, it is necessary to wipe leaf sinuses with a cotton swab in case of stagnation of moisture in them.

Processing should be carried out 2-3 times with a frequency of 5-7 days, depending on the drug until the signs of the fungus completely disappear.

Florists who do not accept chemicals, it is recommended to use folk remedies to eliminate the disease:

1. Garlic. Grind 5 cloves of the plant component and pour 500 ml of warm water. Infuse the mixture for 5 hours in a closed container. Subsequently, clean and use for spraying.
2. Horsetail. 100 g pour 500 ml of boiling water. After 2 hours, clean and use to treat the affected plant.

It should be understood that folk remedies are effective only at the beginning of the development of the disease, as they have a sparing effect. If the situation is critical, it is better to use fungicides.

How to get rid of a pest?

If a white sticky coating appears on orchids, then it is necessary to deal with it with the help of insecticides. Moreover, one should not only spray the leaves, but also water the plants with a working solution. Treatment must be repeated every week until the mealybug is completely eliminated.

The main drugs:

1. "Actellik", "Fitoverm". Dilute any of these insecticides at a rate of 2 ml per 1 liter of water. Stir well and spray the leaves. With a massive accumulation of the pest, it is necessary to moisten the cotton pad in the working solution additionally and wipe the affected areas.
2. "Actara." Dissolve 1.4 g of the drug in 6 l of water. Use the resulting product for watering orchids. This will allow the poison to penetrate the roots, and then into the leaves and stem. This will lead to the death of pests during the suction of cell juice.

An alternative to chemical drugs can be folk remedies for the pest, but it is recommended to use them only at the first signs of damage. During the period of mass reproduction of the mealybug, they will be useless.

1. Add olive oil (50 ml) to 1 liter of water at a temperature of 40 degrees. mix the product. Use to wipe the front side of the leaves in places of mass accumulation of the worm.
2. Mix 10 ml of alcohol, 15 ml of dishwashing detergent and 1 liter of water. Use the mixture to spray affected plants. The use of funds for narrow-leaved orchids is unacceptable.

Prevention

In order not to subsequently observe a white coating on orchids, it is necessary to observe certain rules of maintenance and care:

1. Choose an eastern or western window for plants.
2. Water as the substrate dries in a pot.
3. Periodically arrange a warm shower with further wiping of the sinuses from the moisture.
4. Reduce watering at lower temperatures.
5. Use phytolamps during short daylight hours.
6. The temperature of the content should not fall below 12 degrees.
7. New plants should initially be quarantined for a week.
8. Periodically carry out preventive treatment of flowers 1 time in 3 months.
9. Use nitrogen top dressing from February to May, reducing the concentration of fertilizer by 1/3 of the specified in the instructions for the drug.
10. When transplanting, it is necessary to use a specially prepared substrate of the middle fraction, which will allow the roots to breathe and not to stagnate with water.

Indoor flowers need to comply with the basic requirements of their maintenance, as close as possible to their usual habitat. Otherwise, a white coating on the orchid will appear regularly, which will negatively affect the growth and development of the plant.