What is sick with onions and winter garlic - a photo, name, description and drugs for treatment
ONION DISEASES - NAME AND DESCRIPTION. STRUGGLE MEASURES
In susceptible varieties of winter garlic and onions in the years of epiphytotics, plant death can reach 100% even before the onion harvest begins. So which diseases do the most harm?
One of the most harmful diseases of onions, as well as batun, shallots, chives, leeks and garlic is downy mildew, or peronosporosis.
At the same time, the crop shortage of onion sets and turnip onions can reach 50%. If the infection persisted in the seeds, such plants lag behind in growth, turn yellow, their leaves become covered with a gray-violet sporulation in humid weather, and soon the plants die. Upon infection in the field, elongated yellow spots appear on the leaves at first (in wet weather, a characteristic bloom of spore wear is noticeable on them). With high humidity, the disease spreads rapidly. Secondary pathogens - fungi of the genus Alternaria or Stemphylium, which form a continuous black coating, often settle on the affected leaves.
The main source of infection is seeds, infected bulbs, and perennial onions such as multi-tiered, batun, and shallots. The established hot and dry weather slows down the development of peronosporosis, however, when the air humidity rises, the disease will again begin to progress. Infected bulbs are poorly stored.
Watery spots on the leaves, which eventually acquire a brown color and concentric zonality, are a symptom of alternariosis (pathogen Altemaria porn). Damaged bulbs remain small and rot during storage.
With stemphiliosis (the causative agent of Stemphylium vesicanum), small light yellow or brown watery spots appear on the leaves of onions, garlic, leeks and some other plants.
They gradually grow and darken. Affected areas are covered with abundant dark brown, almost black coating, flower stalks turn yellow, break, the affected plants die. Black plaque sometimes appears on the bulbs in the store: they seem to be covered with a layer of soot. This disease often develops as a secondary infection in plants affected by other diseases, for example, peronosporosis.
Onion rust is distributed mainly in the south, but sometimes manifests itself in the conditions of the Moscow region. This mycosis affects onions, leeks and garlic. The causative agent is a single-host rust fungus, all stages of which develop onion or garlic. Particularly affected is onions overfed with nitrogen fertilizers. The development of the disease favors humid weather. Symptoms of the disease are visible to the naked eye: in spring, orange sporulation pads can be seen on the leaves of onions and garlic. The source of the primary infection is last year's affected plant debris.
See also: How to store onions by science - diseases and fighting with them from A to Z
Fusarium rot of the ground is the most dangerous disease of garlic, but onions and leeks can also affect. The disease develops especially quickly in warm rainy weather, and at temperatures below 15 ° the spread of infection stops. Leaves on the affected plant, starting from ver
Khushkas turn yellow and die in a matter of days. On the dug out bulb, rotten roots are visible, the bulb itself becomes soft, slightly watery. Weakly affected bulbs can end up in storage. There they rot, and between the fleshy scales of the bulb you can see a plentiful white or slightly pink spider web coating with dense pink pillows, consisting of mycelium and spores. Bottom rot more often occurs on plants damaged by an onion fly. Garlic is more resistant to this disease during spring planting.
Onion crop protection is a whole range of activities. The basic rule is strict observance of crop rotation: onions are returned to their original place after 3-4 years. Seeds and planting material before planting are disinfected by soaking for half an hour in a 0, 2% solution of the drug with the active substance fludioxonil.
During the growing season, it is important to maintain optimal soil moisture. Due to the poorly developed root system in the first half of the growing season, onions need moist soil, therefore, in dry weather, plants have to be watered every 3-4 days, pouring 10-15 liters of water per 1 sq. Km. m beds. At a later stage, when the growth of leaves stops and they begin to die, watering is reduced. At this time, with excess moisture, the bulbs ripen more slowly, do not go into a dormant state for a long time. In rainy years, you can recommend installing canopies over the beds.
If possible, watering at night should be avoided and weeds in time to weed out that impede good air exchange. And of course, during the growing season you can not overfeed plants with nitrogen fertilizers.
To protect against fungal diseases, you can regularly spray the onion with a drug approved for use on personal farms, and to keep it better on the leaves, add an adhesive to the solution. But chemical plant protection products cannot be used on onions grown on feathers. After harvesting, all post-harvest residues are necessarily removed and burned.
Every year, a dangerous pest inflicts more and more harm to garlic and other onion crops. onion stem nematode. It attacks plants during the growing season: infected seedlings grow slowly, the first leaf is swollen and curved. With a severe defeat in wet years, seedlings die, and the nematode switches to healthy plants.
Whitish and grayish spots appear on the surface of infected bulbs, the inner scales become gray, soft, granular, unevenly thickened. Cavities form between the scales, and the bulb feels soft and rotten to the touch. The outer scales, and sometimes the bottom, crack, and during the harvesting period such bulbs are without roots. Near the cracks gray spots are visible - clusters of nematodes in an anabiotic state. The affected garlic does not grow, the false stem thickens, the leaves turn yellow and dry, the bottom becomes rotten and falls off.
Control measures: crop rotation, return of the affected plants to their original place no earlier than after 4-5 years, thermal disinfection of infected soil and treatment with nematodes. During the growing season, affected bulbs and plant debris are collected and destroyed, and only healthy planting material is used for planting, checked under a microscope for the presence of a pest - small worms 1-1,5 mm long or their cysts.
What else is dangerous nematode? Having appeared once, she can take the garden out of circulation for 20 years - this is how much her cysts live. And they are not afraid of either frost or drought. The most effective protection is “wedge-wedge”, that is, the use of an environmentally friendly biological product based on entomopathogenic nematodes of the species Steiner-nema carpocapsae, designed to combat soil-borne insect pests and nematodes. After entering the soil, the nematode larvae in the absence of a host insect become inactive, and in this form they can expect pests for more than 2 years.
See also: Rotting onions? Photos, name and description of diseases + how to deal with them
ONION DISEASES WITH DESCRIPTION - VIDEO
© Posted by T. SEREDIN, Senior Researcher, Onion Crop Breeding and Seed Laboratory
Below other entries on the topic "Dacha and garden - with their own hands"
- Folk remedies for diseases and pests - proven methods from gardeners: collection 5
- Protection of the garden from pests and diseases - photo and description + set of processing measures
- How to deal with gall aphids on currant - means and methods
- Phytophthora of potatoes (photos) - prevention and control: the advice of the SPECIALIST
- Protection of currants in early spring: step by step instructions
- Pest preparations - large memo table: name + description from what and whom
- Three treatments of tomatoes - hydrogen peroxide, microbial and mineral solutions
- Pests of vegetables: thrips, mites, aphids and cicadas - photo and description, signs
- The main pests of apple trees and how to deal with them
- Soap-oil solutions and emulsions from pests of domestic plants
Subscribe to updates in our groups and share.
Let's be friends!
#
I COVER THE GARLIC WITH MUSTARD
Winter garlic is the most stable way to obtain a harvest. In 2023, I had it extremely adequate: without little things and giants, just as it should be. However, many suffer from Fusarium bottom blight on garlic. There is a proven method: plant the cloves on a bed of sand and/or vermiculite, as is usually done with tulips and lilies. Then the bulbs will be larger and cleaner, and the garlic will have little chance of getting sick.
There are other rules against fusarium.
We plant garlic on average a month before frost - in Siberia this is the end of September. We prepare a bed for garlic in advance: we add dolomite flour and potassium for deep digging.
magnesia according to the norm for your soil, on average for chernozem soil with pH6 - this is 150 g of dolomite and 80 g of potassium magnesia. You can replace everything with 120-150 g of borophosphate.
We sow mustard, which we pull out on the day of planting garlic. Mustard is the best biofumigator for soil.
Before planting, soak the garlic cloves in the preparation “Healthy Earth”, “Fitosporin-M” or “Maxim”.
We loosen the soil with a flat cutter to a planting depth of 8-10 cm. Then we plant the cloves and cover them with torn mustard.
#
If winter garlic sprouted
If the garlic planted before winter managed to germinate before frost, I mulch the beds abundantly with sawdust or straw. I cover it with spruce branches so that the mulch does not scatter and the snow lingers better. In the spring, as soon as the snow melts, I remove the shelter.