How to treat peronosporosis onion
Onion peronosporosis, or powdery mildew, is a fairly common disease. Peronosporosis of garden onions is a fungal disease that attacks any part of the plant. It occurs in cold and rainy weather, when moist and moist soils are formed. Fungal spores can be spread by raindrops and wind over a decent distance. It is rather difficult to identify such a disease, since at the initial stage it does not manifest itself in any way.
Peronosporosis onion
In an advanced stage, onion leaves begin to turn yellow. First of all, the disease can be seen at the ends of leaves. Control measures for the treatment of plantings should begin as soon as the first lesions of onion leaves become visible, otherwise the disease can spread to all plantings. To avoid this, it is best to carry out regular prophylaxis and spraying against fungal infection. You can see what the disease of peronosporosis looks like on onions, you can take a photo.
Signs of onion peronosporosis
- Onion feathers have rusty spots or streaks.
- The ground part with a purple bloom.
- The feathers of the onions may stick to the soil and the bulbs themselves may not fully ripen.
How to identify downy mildew in onion plantings
After planting onions in open ground, after three weeks, the disease can attack the plantings, at which time the first lesions are visible. The mealy fungus is especially dangerous for the testes, because the seeds obtained may simply not yield a harvest. Bacteria can overwinter in perennial onions and become active immediately after planting.
To protect yourself and the crop, it is better to choose varieties with flat leaves, for example, allspice or slime - they are least susceptible to fungus. If the air humidity is more than 90% and the soil dries out poorly, then a purple bloom can be seen on the aboveground part of the plantings.
If the planting is not treated, then the diseased bulb and feathers begin to become covered with rusty spots and rot. Peronosporosis of onions most often occurs in cool and rainy weather, because this creates suitable conditions for the reproduction of the fungus. Also, the disease attacks plantings in the shade, and those to which fresh air streams do not penetrate. Conidia thrive at around 90% humidity. In bright sun, bacteria do not attack plantings, since the sun's rays burn out all viruses and fungus, so if the sun comes into contact with the garden and the soil is relatively dry, then the chance of developing the disease is minimal.
Onion treatment methods
To detect the disease on time, you need to regularly inspect your plantings for various spots or putrefactive plaque. You should also make sure that there are no trash cans or waste with infected plants near the plantings. Bacteria can spread even from a distance. Peronosporosis of onions must be treated in the early stages of the disease, then most of the plantings can be preserved. Peronosporosis of onions and measures to combat it are primarily to reduce watering, since due to constant humidity, the fungus actively multiplies.If during this period the plantings were fed with nitrogen or organic fertilizers, then for a while you need to change the type of dressing.
It is best to process the onions with phosphorus or potassium dressings. During the active growing season, plantings should be sprayed with fungicides to combat downy mildew. You need to proceed from the state of the onion and the neglect of the disease. Various agents can be used to treat peronosporosis. Basically, drugs such as Bordeaux liquid 1%, Polycarbacin suspension or Arbamide are used. Polycarbacin or Arbamide should be diluted in 10 liters of water. The agent, which has been chosen, must be added to the water in an amount of about 30-40 g. Repeated treatment with one of the preparations is carried out 1-2 weeks after the first phase of treatment. If the plans are to process the plantings with Bordeaux liquid, then it is better to carry out the treatment several weeks before harvesting.
If any drugs were used to treat peronosporosis, then onion feathers should not be eaten, only the onion is suitable for eating.
Traditional methods of combating peronosporosis
If the use of chemicals to combat the disease seems unjustified, you can use folk, more gentle methods. Many gardeners have successfully used fermented weed grass to treat this disease. It is necessary to collect half a bucket of weeds, clean it of dirt and soil, then the prepared weeds must be finely chopped and filled with hot water. This fermented herb should be left in a bucket of water for several days. This is done so that the weeds are infused and a healing solution is obtained. When the weeds are infused, the water must be filtered and poured into a spray bottle. The resulting solution can be sprayed on plants affected by peronosporosis. Spraying is best done in the evening.
Also, some gardeners successfully spray with fermented milk products previously diluted in water. For example, milk, kefir or whey must be diluted in cold water in a ratio of 1:10. The resulting mixture should be filtered, poured into a spray bottle, and then start to spray the planting. It is advisable to spray in the evening so as not to burn the onion feathers.
Wood ash has also proven itself well in the fight against peronosporosis. It is necessary to carry out dusting of the beds at the rate of 1 sq. m 50 g of ash. The methods of struggle can be different, the main thing is to notice the effectiveness of the procedures after the treatment with folk remedies. Several methods should be combined, then there are more chances that the spread of the infection can be avoided.
Prevention of onion diseases
In order not to fight peronosporosis, you need to take all measures to protect the plantings. Before planting seeds, they must be disinfected. If this is not done, then there is the likelihood of spreading the fungus in the future harvest. Bulbs to be planted should also be checked for infection and decontaminated. It is necessary to purchase onions for planting only from trusted suppliers or in gardening stores. The bulbs should be planted only on the sunny side of the site, where there is no shade. After harvesting, you need to remove all residues from onions and husks, since in a diseased plant bacteria can wait out in any part of it.
The soil should not be sandy or loamy. In such soils, fungal diseases are least likely to occur. The crop should only be harvested in dry weather. If there are damaged plantings, then they should not be stored in your area, since the fungus can spread to other beds. It is not worth planting onions in the same place every year; you need to change the planting place every 3-4 years. Where onions were previously grown, you should plant cucumbers, cabbage or pumpkin. Perennial varieties are best planted in isolation from other onion varieties.
The bulbs must be stored properly after harvest.Beforehand, they should be dried and removed to a well-ventilated place without direct sunlight. Even if there is an infection in some of the bulbs, further spread can be avoided. If you follow the simple rules for planting and caring, you can easily grow healthy and high-quality onions.