Diseases Of Onions

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Photo: nehru / Rusmediabank.ru

Diseases of onions - rarely any owner of a summer cottage does not grow onions, however, diseases of this plant can lead to the fact that the harvest may not be seen at all.

A disease such as peronosporosis is better known as downy mildew. Such a disease can ruin the entire onion crop. This is a fungal disease that occurs due to the fungus hibernating in the bulbs and in those residues that remain after harvesting. The disease develops most actively at temperatures of 9-14 degrees Celsius. High humidity is also favorable for the development of the disease. On plants susceptible to this disease, pale spots can be seen, and the leaves themselves become curved over time. When the weather is warm and humid, the leaves will be covered with a grayish-purple bloom. This disease will develop very quickly and spread to literally all the leaves. The leaves will begin to fall and wither, and the arrows themselves will lose their shape. The disease can be transmitted through raindrops as well as air currents. In addition, the disease can develop through the hands when the plants are processed.

As for the methods of dealing with this disease, you should not plant onions too thickly. For planting, you should also choose well-ventilated areas in your summer cottage. The plant should be fed with superphosphate, which should be done in the second half of the growing season. Such measures will significantly reduce the course of this disease. When the disease has spread very strongly, you will need to spray the plant with a 1% solution of the so-called Bordeaux liquid.

Another dangerous disease known as bacterial or wet rot. This disease occurs due to three bacteria, they will enter plants through a variety of wounds or through insect damage. Brown and brown ulcers will appear under the scales. And as for healthy ones, there will be a rather dark layer of soft tissue, an unpleasant odor will come from such scales. Infection occurs most often on rainy days. These bacteria will enter the onions along with various insects and nematodes. When an infection of the bulb occurs through the false stem, the disease will manifest itself as neck rot. Actually, this disease in its very initial period is easy to confuse with the so-called cervical rot.

In order to prevent the occurrence of such a disease, the seeds and all planting material should be disinfected, which must be done immediately before planting. Also, during the growing season, already infected plants should be disposed of, and plant residues must be burned. As a preventive measure, the application of phosphorus fertilizers is also suitable, this will help increase the resistance of onions.

A viral disease such as the yellow dwarf virus is also quite common, but it is in the southern regions that it will infect plants most intensively. At the very beginning, this disease appears on the bases of the leaves, as well as in the arrows. On these parts of the plant, small yellow spots with a brownish tinge become noticeable, which will be arranged in stripes. Over time, the leaves will begin to bend, and then curl at all. Such plants will noticeably lag behind in growth, and then they will begin to rot.

Carriers of these diseases are nematodes and four-legged garlic mites, as well as aphids. As for preventive measures, it is necessary to regularly inspect the state of the plantings and eliminate all diseased plants. And the pests themselves, which are carriers of this disease, must be immediately destroyed.

It should be noted that pests are very often located on plant debris and weeds, as well as in the upper layers of the soil. Therefore, a necessary measure is to loosen the soil and destroy plant residues.