Content
If onions rot in the garden, the reasons can be very diverse. Problems with roots and bottom appear due to exposure to pests, fungal diseases, and also due to unfavorable growing conditions.
Why onions rot in the ground and what to do
If the onion in the garden is rotting from the root, first of all you need to pay attention to the growing conditions. The crop may die due to unsuitable soil composition, waterlogging and other factors.
Improper watering
Onions in the garden need good moisture. But if the soil at the roots of the vegetable is constantly waterlogged, then sooner or later bottom rot will appear. The garden bed should be watered moderately, in accordance with the actual condition of the soil.
If the weather is rainy, additional moisturizing should be abandoned altogether. When watering onions, it is important to use warm and soft settled water.
Cold water when watering harms onion roots; rot often appears on them
Excess nitrogen
Onion rot in the garden can appear due to excess nitrogen in the soil. The vegetable needs the substance mainly in the spring to gain green mass. But then the need for nitrogen decreases sharply. If you continue to apply appropriate fertilizers, they will not be absorbed, and the compound will remain in the soil.
A balanced approach to fertilizers helps to avoid onion rot. After the vegetable is sufficiently strong and begins to bloom, nitrogen fertilizing is reduced to a minimum. The main attention is paid to the addition of potassium and phosphorus, which strengthen the roots, protect them from rot and are responsible for the formation of succulent bulbs.
Poor quality planting material
Onion sets rot if the quality of the material is initially very low. Before planting, you need to carefully sort out the bulbs and assess their condition. The following cannot be used for sowing:
- bulbs with rotten sides, spots and damp upper scales;
- sowing with an unpleasant odor;
- onions with uncharacteristic peel color.
Even if the planting material looks healthy, it must be subjected to special treatment. The sets are soaked in a weak solution of potassium permanganate for ten minutes, and then washed and dried.
Violation of crop rotation rules
If the onions begin to rot, this may indicate poor crop rotation. It is not recommended to grow vegetables in the same place for more than two years in a row. Ideally, you need to plant onions in a new area every year.
Violation of this rule leads to soil depletion. The earth does not have time to recover from the onion, and even fertilizing does not correct the situation. In poor soil, rot often develops in the roots of the plant. In addition, neglecting crop rotation increases the likelihood of pests and fungi on onions.
Bad weather conditions
Onion rot at the bottom can be caused by bad weather. Soil swampiness is often caused by prolonged rains, and it is quite difficult to influence the situation in this case. But if there is a good drainage system in the garden bed, the onions will feel much more comfortable. If you properly dig up the area before planting the crop and add sand or expanded clay to the soil, root rot will not appear even in a damp summer.
Diseases
Against the backdrop of unfavorable growing conditions, onions in the garden can be affected by fungal diseases. Many of them cause, including bottom rot.
Downy mildew (downy mildew)
Onion feathers rot due to downy mildew, a disease caused by the fungus Peronospora destructor. The disease affects beds mainly in damp and cold weather. Onions can be damaged both in the early stages of the growing season and during the fruiting stage.
Downy mildew affects, first of all, the feathers of the crop - they slow down their development, and then turn pale, yellow and deformed. Gradually, a grayish-purple coating appears on them, representing fungal spores, and rot occurs.
The development of onion downy mildew and rot is facilitated by the presence of unharvested plant debris in the garden bed
At the first signs of downy mildew, it is recommended to treat onions with Fitosporin or copper sulfate. The soil is shed with a medicinal preparation 2-3 times at weekly intervals. For prevention, it is recommended to treat the beds with a green herbal infusion or a solution of wood ash.
Fusarium onion (bottom rot)
Onion bulbs rot due to the action of the fungus Fusarium oxysporum, which leads to the development of fusarium. The disease manifests itself as yellowing and curling of the feathers of the vegetable. If you dig an onion out of the ground, you will see that its roots have darkened and a brown watery spot has appeared on the bottom. If the rot has severely affected the vegetable, it will be very easy to remove it from the soil.
The likelihood of developing rot on onions due to fusarium increases if there is damage to the roots and bottom
Fusarium gets on onions through the soil, as well as with water or wind. To protect the beds from fungus, it is necessary to give preference to varieties with high immunity, observe crop rotation and use only sterile tools to care for plantings.
Treatment of fusarium can be difficult due to the fact that the disease very quickly affects the root system. If rot has appeared on the bottom of the onion, then it is no longer possible to save the vegetable. Affected plants are simply removed from the garden bed and the soil is treated with Fitosporin solution. At the very first stages of the development of the disease, spraying with Quadris or Fundazol is beneficial.
Cercospora
The disease is caused by the fungus Cercospora duddiae Welles, which overwinters in soil and plant debris and is also carried by wind and rain. The development of the disease is indicated by grayish-brown spots with a yellow border on the leaves, the gradual death of feathers and a slowdown in the development of bulbs. In the later stages of the disease, the underground parts of the vegetable are affected by rot and the crop dies.
For the treatment of cercospora, Bordeaux mixture and the drug Fitosporin are used. The beds are treated with fungicidal solutions at intervals of 8-10 days.For prevention, it is necessary to observe crop rotation when growing crops and disinfect the seedlings before planting.
Warming up the sets before planting at a temperature of 40 °C for six hours helps prevent cercospora and onion rot.
White rot
White rot of onions develops under the influence of the fungus Sclerotiumcepivorum Berk. The provoking factor for the disease is waterlogging of the soil. White rot occurs when vegetables are grown in one place for a long time, when there are infected plants in the beds and when low-quality seed is used for planting.
In the first stages of the disease, the green feathers of the onion turn yellow. Gradually, the leaves begin to die, white mold and wet rot with black dots-sclerotia appear on the scales and roots.
If the white rot has spread to the underground parts, it is impossible to save the onion, all that remains is to destroy it
At the first symptoms of the disease, it is recommended to remove all affected plants from the garden bed and spray healthy ones with copper-containing preparations. Prevention of the disease is ensured by compliance with the rules of crop rotation.
Cervical rot
Neck rot develops under the influence of the fungus Botrytis allii, which actively multiplies at high humidity in decomposing plant debris. The disease can be recognized by the appearance of soft, porous areas on the neck of the onion. The upper scales become covered with depressed spots and gray mold with black dots, and the vegetable gradually wrinkles and dries out.
Symptoms of neck rot usually appear in the fall, a couple of months after storing onions.
If symptoms of neck rot appear in the garden, the onions should be watered with 1% Bordeaux mixture. If corresponding symptoms are detected in vegetables in storage, the crop should be sorted. All affected bulbs are destroyed.
Neck rot often appears in beds when plants are planted too densely, when there is an excess of nitrogen in the soil and against the background of waterlogging. To prevent the disease, you must carefully follow the rules of agricultural technology. Only well-dried onions should be stored.
Pest infestation
Onions rot not only due to fungal diseases and unfavorable conditions, but also as a result of pest damage. Several parasites pose a particular danger to the crop.
Onion mite
Onion mites suck moisture and nutrients from onion scales. As a result, the leaves of the vegetable become covered with light spots, the stems become deformed, and rot appears on the bottom. The bulbs gradually become dehydrated, decrease in size and become shriveled.
The onion mite is hardy and resistant to heat and frost.
You can get rid of onion mites in your garden beds using the drugs Akarin and Karbofos. It should be taken into account that the pest quickly develops immunity to chemicals. Priority should be given to prevention - thorough autumn digging and disinfection of the soil.
Onion fly
The pest lays eggs in the upper scales of onions or in the soil in the garden bed.The hatched larvae feed on the juicy pulp, as a result of which rot appears on the vegetable and the crop dies partially or completely. The parasite first attacks onions usually at the end of May. The feathers of the vegetable begin to turn yellow and die, and a noticeable rotten smell emanates from the beds.
During the summer, the onion fly produces three generations of larvae
The likelihood of onion fly occurrence increases if you neglect the autumn digging of the soil and disinfection of planting material. To repel the pest, it is recommended to plant carrots next to onions in the garden - the parasite does not like its specific smell. The soil in the beds needs to be loosened regularly; it is useful to spill the soil with a weak solution of table salt from time to time.
If the onion fly has already attacked the plantings, it is necessary to spray with an infusion of tomato tops, pine needles, valerian or mint. Dusting the beds with tobacco dust is also beneficial. Treatments are carried out at intervals of 5-7 days until the pest is completely eliminated.
Onion thrips
The onion rots inside amid the activity of onion thrips, a small insect up to 0.8 mm in length with a brownish body. Both the adult parasite and its larvae feed on vegetable juice and cause maximum damage to plantings in dry and hot weather.
Signs of the presence of thrips include silvery and whitish spots on onion leaves, as well as yellowing and wilting of feathers. If you do not fight the pest, then gradually rot will appear on the underground part of the vegetable.
Onion thrips spend the winter in plant debris and upper layers of soil. Therefore, careful autumn digging of the soil helps prevent its occurrence. In addition, it is recommended to thoroughly disinfect and dry onions before planting.
To protect against onion thrips, the beds can be sprayed prophylactically with an infusion of celandine.
If the pest has already appeared in the beds, it is necessary to spray with tobacco or garlic infusion. Products with a strong odor repel the parasite. It is useful to place paper or cardboard strips coated with glue in the garden - adult pests will be trapped and will not be able to reproduce.
Weevil
Onion heads rot if there is a weevil in the garden - a small black beetle with an elongated proboscis. The adult parasite feeds on plant juices, and the larvae gnaw out the ripening fruits from the inside.
When attacked by a weevil, whitish spots and a grayish-green coating appear on the onion. Rot develops quickly, causing the ripening vegetable to darken and die.
Planting onions in a well-ventilated place and regular weeding of the beds help prevent the appearance of weevils.
The weevil affects onions in the garden due to poor quality care, the presence of plant residues in the beds and thickened plantings. Regular weeding and timely soil cleaning help prevent the appearance of the pest. In addition, it is recommended to preventively sprinkle the soil with wood ash or dry mustard. You can plant a spring onion near the vegetable - it will serve as a bait for the weevil and distract the pest from the main crop.
If the parasite has already appeared in the garden, it is necessary to remove and destroy severely damaged plants on which rot has formed. The remaining plantings are treated with a solution of Karbofos, prepared at the rate of 60 g of the drug per bucket of water.If necessary, spraying is repeated several times until a complete result is obtained.
Onions should be treated with insecticidal agents to treat rot in dry but cloudy weather. In bright sunshine, spraying is not carried out.
Onion nematodes
The nematode is a dangerous pest of onions, which is a microscopic roundworm. Lays eggs in the scales of the vegetable, the parasite larvae feed on the juice of the fruit, causing rot and leading to the death of the crop.
The nematode itself is almost impossible to notice with the naked eye. But its presence is evidenced by twisted and swollen stems, as well as thickened and discolored fleshy onion scales. If you cut the affected fruit, the inside will be loose and grainy.
Rot of bulbs due to nematode damage often leads to the appearance of a sharp unpleasant aroma in the beds
The nematode gets onto the onion from contaminated soil, enters the beds from dirty equipment or through low-quality compost. To prevent the appearance of the pest, it is necessary, first of all, to carefully follow the rules of crop rotation and not plant the crop in the same place earlier than after three years. In autumn, it is recommended to spill the soil in the beds with a solution of Carbation at the rate of 200 ml per 1 m2.
You can protect onions from nematodes by pre-treating the planting material. Seeds or sets are soaked in a light solution of potassium permanganate for ten minutes, after which they are dried. When growing crops, it is also recommended to regularly loosen the soil and monitor its acidity. The nematode appears more often on acidic soil, so if necessary, dolomite flour or lime is added to the soil.
It is almost impossible to cure onions affected by the pest - they are quickly destroyed by rot. It is necessary to immediately remove all affected vegetables from the garden and thoroughly water the soil with disinfectant solutions.
Conclusion
When onions rot in the garden, you need to inspect the plantings and, if necessary, treat them against diseases or pests. If the plants are not affected by fungi and parasites, the approach to agricultural technology should be reconsidered. Rot usually develops due to waterlogging and acidified soil.
