Every gardener grows onions in the beds. With improper care, onions can be exposed to various diseases.
Therefore, the vegetable should be carefully looked after in order to get a good harvest. Onion diseases are manifested by various symptoms. Disease control depends on pathogens that are transmitted through planting material or spread through the soil.
- The most common diseases of onions
- Recommendations for protection and prevention
- How to deal with disease
The most common diseases of onions
Onions grow in almost every garden or country house, because they are among the most used vegetables. Unfortunately, it is onions that are often exposed to diseases and suffer from various kinds of pests. The lion's share of all onion diseases are fungal diseases, which differ in the "method" of inflicting damage and their properties. What they have in common is that the damage to the crop is very serious.
Gray neck rot. The causative agent of the disease is a fungus. Symptoms of a fungal disease usually appear during storage of the crop. In the region of the stem end, softening of the bulb is observed, on which a fluffy gray coating appears. Rot can also appear in certain areas - on the side or in the area of the bottom. If the onion is cut, then the inside will have a baked appearance. Leaves with cervical rot become pale, gradually dry out and rot.
Rust. The causative agents are various bacteria and fungi. On the leaves, yellow spots are observed, located in rings. With severe damage, onion leaves dry out prematurely. The disease develops strongly in wet weather and with the introduction of large amounts of nitrogen fertilizers.
Smut. A fungal disease characterized by the appearance of dark streaks and elongated swellings on the leaves. The disease usually occurs when sowing onions in the same areas. Cutting the bulb reveals dark-colored smut spores. Spores begin to germinate at a temperature of 13-20 degrees.
Mosaic. A viral disease characterized by the appearance of small yellow-white specks or light green stripes. The onion leaves begin to dry out. Severe infection can lead to the death of the plant. The disease is transmitted by a garlic pest - a four-legged mite.
Bacteriosis When putrefactive bacteria penetrate into undried bulbs, bacteriosis develops. Quite often, rot can be found during storage of the crop. With bacteriosis, softened brown tissue can be observed on the cut of the bulb. The leaves begin to turn yellow, and the roots gradually rot, from which an unpleasant odor appears. Bacteriosis develops with a rapid change in weather conditions, sunburn and improper storage in humid conditions.
Downy mildew or Peronosporosis. It is a fungal disease. It develops in the spring when onion seedlings grow back. When infected with a fungus, the leaves turn yellow and break. Pale green spots can be seen on the arrows of the bow. Peronosporosis develops rapidly in wet weather.
Stemphiliosis. The mushroom Stemphilius affects the onion. This mushroom is especially dangerous for the testes. On the leaves and arrows of the plant, you can find brown-purple spots with a bloom, brown or smoky-brown spores. The leaves break and the seeds become shriveled. The fungus grows rapidly in dry weather. In this form, they can be stored for a long time.
Green mold. A fungal disease in which watery brown spots can be seen on the bottom of the bulb. This makes the bulbs appear empty. High temperature and humidity during storage of the crop contribute to the appearance of the disease.
Fusarium. The causative agent of the disease is a fungus. The disease is characterized by the death of leaves, the presence of a yellow or white plaque on the bottom with colorless spores. The disease develops in dry weather with high humidity. Infection can occur through seed or soil.
Recommendations for protection and prevention
To protect onions from fungal diseases, the following measures must be observed:
- Produce deep plowing from residues.
- Observe crop rotation.
- Discard planting material with signs of rot.
- Land early.
- Apply the appropriate dose of fertilizer while observing the terms.
- Harvest onions in dry weather.
- Be sure to dry the onions before storing.
To protect the onions from smut before sowing, it is recommended to treat the soil with Bordeaux mixture, and the seed in a fungicidal solution.
For prophylaxis and protection in the fight against onion bacteriosis, the seed should be carefully examined. It is also recommended to spray with Bordeaux liquid. To prevent the spread of bacteriosis to other bulbs, it is imperative to remove damaged and diseased plants during harvesting.
How to deal with disease
The main measure in the fight against downy mildew or downy mildew is to obtain high-quality seed. For this purpose, it is advisable to place crops away from perennial onions, testes and turnip onions. If this disease is found, then spraying with fungicidal agents should be carried out: Arcerid, Polycarbacin, Ridomil, Polykhom, etc.
With stemphiliosis, it is necessary to follow agrotechnical techniques, as well as fight against factors that contribute to the death of leaves. To combat green mold, onions should be sown away from infected areas. Be sure to dry the harvested crop before storing. Early ripening onion varieties are less exposed to green mold.
To protect the onion from bottom rot, crop rotation must be observed. You can plant onions in their original place no earlier than 5 years. Thoroughly process the planting material with a TMTD suspension. To prevent the appearance of onion diseases and harvest a high yield, you should properly care for the plant, sow on time and follow the storage rules.
Video on what to do if onions are just starting to turn yellow: