Powdery mildew on onions: how to deal with it and what to do?

From fungal infections, powdery mildew is common on onions, every vegetable grower should know how to deal with it. Otherwise, the disease will begin to progress, spreading to neighboring plants. Zucchini, cucumbers, and pumpkins suffer the most from the pathology. You can save the crop by applying measures to combat pathogenic microorganisms. Use processing and chemical means, and folk. You need to know the symptoms of the disease, why it appears and how to avoid infection.

Description of disease

As soon as they do not call powdery mildew, and ashtray, and linen. Of the fungal diseases that affect both vegetable and berry crops, powdery mildew is the most common.The fungus parasitizes vegetation, reproducing by spores that look like miniature brown balls. The name of the disease reflects the main sign of infection.

In addition to the true disease, found on vegetables and downy mildew, or downy mildew. The types of pathology differ in the location of white plaque. In true powdery mildew, infection of the plant begins on the outside of the leaf, in false - on the inside.

But the mechanism of action of spores on the plant organism is the same. Absorbing the pulp of the green parts, which is rapidly necessary for life, the fungus develops.

Pasitizing on onions, the mycelium depletes the plant. With raindrops, wind, spores pass to other plants They are carried by gardeners themselves, not following the rules of care. From the moment of infection lasts from 5 days, as the first symptoms appear. Among the signs of the disease is not only the appearance of white plaque.The leaves, as if doused with lime, turn yellow. Necrotic brown spots appear on the stems, which indicates the neglect of the pathological process.

Conidia are well preserved in the harvest. In rooms with temperatures above 15 degrees Celsius and humidity of 85-90 percent, the infection spreads instantly. Therefore, protecting onions from powdery mildew is an important stage in the cultivation of vegetables.

Why does powdery mildew appear?

Fungal spores spread when:

Water the plants. If the onion is affected by powdery mildew, along with water splashes, microorganisms are blown onto he althy crops.
Hot weather accompanied by high humidity. The infection develops rapidly in rainy weather. The air is saturated with moisture vapor, which is favorable for the spread of powdery mildew.Conidia are formed 5-10 days after hitting the plant. 15 degrees of heat is enough for them to develop activity. Moreover, plant cells are weakened under such conditions.
Planted thickly. In contact with each other, the onion stems take on the fruiting body of the fungus. This is how new lesions are formed. This happens in beds where there is no access to fresh air, there is no wind movement.
The earth contains a large amount of nitrogen.
The garden was not cleaned after digging up vegetables. Spores overwinter in plant debris, covered with snow, and remain viable.
Pests attack onion plantings. Carriers of the fungus are onion fly, nematodes, aphids. By damaging plants, pests make them vulnerable to fungal infections.
Seed material contaminated. Spores remain on the set to then develop on the stems and leaves of the vegetable.

Whatever the cause of the disease, it must be disposed of at the first signs.

What can I pour over onions?

The main task in the situation, how to deal with powdery mildew on onions, is to reduce the lesion. Therefore, all parts of plants covered with white bloom are cut out with subsequent burning. Remove diseased plants from the garden, eliminating them entirely.

At the initial stages of development of powdery mildew, a preparation for spraying is prepared for plants. Dissolve potassium permanganate in warm water. A high concentration solution kills spores of microorganisms. Destroys powdery mildew fungus and soda ash, a spoonful of which is dissolved in a bucket of water.

Another way to stop the spread of the disease is to spray with a solution of copper sulfate. Dissolve ten grams of the substance in half a liter of hot water, pour it into a bucket of warm water. In order for the solutions used to be better retained on the plants, one hundred grams of laundry soap is added to a bucket of liquid.Use the processing of beds with onions 3-4 times a month.

Bordeaux liquid is used two weeks before onion harvesting, although many leave the product unattended. Vegetable growers believe that the Bordeaux mixture is suitable only for the prevention of diseases. Although a 1% preparation does an excellent job with powdery mildew at the beginning of the development of the disease.

How else can you save the bow?

When the first signs of disease are detected, the plant:

moisturized with tincture of iodine (10 ml) dissolved in ten liters of water;
treated with Fitosporin for powdery mildew at a ratio of one gram per liter of liquid;
sprayed with a mixture of copper sulfate (10 grams), soda ash (50 grams), laundry soap (200 grams) and two liters of water diluted in a bucket of water.

Chemical preparations, fungicides work more effectively: Agrolekar, Chistoflor, Ridomil, Skor. Use the funds in accordance with the instructions. Preparations act against the fungus on the plant, on the bulbs. Fungicides are used to control other fungal infections.

It is necessary to spray with chemicals three times during the growing season. You can repeat the procedure after one and a half to two weeks. But onion plantings are processed twenty days before harvest. Processing of onions against powdery mildew is also carried out with folk remedies.

Folk remedies for powdery mildew

Vegetable growers have developed their own methods of dealing with powdery mildew, using folk remedies to eliminate the disease.

To fight infection, weeds are pulled out, put in a bucket and poured with boiling water. The infusion is prepared for several days, fermenting. After straining the finished medicine, sprinkle onion feathers.

Another remedy is prepared from separated fermented milk whey, it is diluted with cold water in a ratio of 1:10. To enhance the effectiveness of the solution, add a teaspoon of copper sulfate.

An infusion of fresh mullein diluted in water is prepared for three days. After mixing, filter and add a liter to a bucket of water. Treat the onion with a folk remedy in the evening.

Tobacco or onion peel infusions, which are made the day before treatment, will help to cope with peronosporosis. Many gardeners advise saving bulbs infected with powdery mildew in a simple way. It is necessary to warm the collected onion heads well in the sun, dry. Then pathogenic fungi will die.

Preventive measures

In order not to use chemicals to combat powdery mildew, to make your work easier, you need to think in advance about measures to prevent a fungal infection.

Measures to prevent powdery mildew on onions include:

compliance with the rules of crop rotation, not planting onions where batun, shallots, garlic grew;
pre-soaking seeds and sevka before planting in a solution of potassium permanganate;
ensure air circulation in the beds, avoiding dense plantings;
disinfection of tools, devices to carry out garden work without fear of infecting vegetables with powdery mildew;
implementation of watering in the morning to allow the plants to dry;
applying less nitrogenous fertilizers and more mineral complexes with potassium and phosphorus.

As a preventive measure, vegetable beds are sprayed with a solution of whey, an infusion of wood ash. During the season, any garden weeds are also used, sprinkling with infusion of planting a vegetable plant.

After digging up the ripe onion, the dry stems and leaves are raked and destroyed. Indeed, pathogenic organisms are preserved in plant waste, which are activated in the spring.

It is mandatory to carry out preventive treatments of bulbs collected from the garden with fungicidal preparations.