How to deal with late blight on cucumbers: treatment regimens

Country cultures are demanding to care for and sensitive to diseases... Fungi, bacteria, pests attack day after day.

It is not surprising that sometimes they give up in the fight against all kinds of diseases. Trying to defend the harvest, summer residents use different methods - chemical, biological, folk. But there are diseases that are very difficult to cope with. For example, late blight. We will tell you what late blight is, why it appears on cucumbers and how to deal with it, and the photos will help you better understand the problem.

What is late blight

Plant disease, the name of which is translated from ancient Greek as “destructive”, “destroying”, “fatal”, is late blight.

Phytophthora is a genus of fungi that infects plants and causes disease. There are about 100 species of phytophthora mushrooms.

It reproduces by zoospores, which perfectly tolerate wintering in the ground, are cold-resistant, love warmth and moisture. If the disease is not detected at the initial stage, it is difficult to cure it. In case of deep damage, a radical method is used - they completely get rid of the plants.

Reasons for the appearance of late blight on cucumbers in a greenhouse and open field

Late blight appears more often in greenhouses and greenhouses, but this problem is not uncommon in the open field. Observing the rules of planting alternation, the proximity of crops and complete cleaning, they seek to remove phytophthora in their area.

There are many reasons for the appearance of the fungus, mainly air humidity over 75% and ambient temperature + 15 ... + 20 ° С.

Other reasons:

• open ground is characterized by sharp drops in warm daytime and cold night air temperatures;
• frequent and abundant watering of cucumbers contributes to the flooding of the soil under the plants;
• high ambient humidity at the same time low air temperature;
• dense planting of cucumber bushes in the greenhouse;
• incorrectly selected site for planting, where little sun falls;
• exceeding the permissible content of lime in the soil;
• the seed material was not disinfected before sowing;
• in case of violation of the neighborhood of crops on the site, the infection enters the cucumber beds from the outside;
• wrong or insufficient plant feeding, scarcity of soil and, as a result, the weakness of plants in resisting diseases;
• insufficient ventilation of greenhouses;
• the remnants of the crop or tops have not been harvested for the winter;
• diseased bushes were removed, but not destroyed, due to which the fungus from the compost pit gets back to the beds;
• on open ground, the wind causes the spread of microspores of the fungus over the site, therefore fences or alternation with beds with high tops are necessary;
• the infected bushes were not removed immediately after the detection of the disease, the transfer of the disease from one plant to another was allowed.

Signs of late blight

It's easy to miss a disease. It begins to appear with small brownish-brown spots on the leaves, as in the photo.

If the sheet is turned over, a white cobweb is visible from the underside, barely perceptible to the eye. In the next stage of the lesion, the leaves begin to curl, turn yellow and fall off.

The absence of ovaries also signals the development of late blight. If there are fruits, soft brown spots are formed on them, similar to rotting areas. Sometimes, when the disease is advanced, there is a persistent smell of rot.

What is the danger

By itself, late blight is not dangerous to humans. You can safely eat fruits affected by late blight. However, no one wants to eat rotten cucumbers and other vegetables. In addition to the unattractive appearance, they also have a corresponding smell. Cucumbers from an already cured bush also look unappetizing. They are unevenly colored, have tuberosities.

The danger lies in the vitality of this type of fungus: cold and heat are not afraid of it. Once faced with this disease, summer residents then for years trying to remove it from the site.

The disease affects cucumbers, tomatoes, eggplants, potatoes. Affected plants do not bear fruit: tomatoes do not turn red, cucumbers do not set, potatoes lose their tops and do not form tubers. As a result - a meager harvest or its complete absence.

Ways of struggle, treatment regimens and recipes

Late blight on cucumbers is treatable at the initial stage of the disease. The more severe the stage of infection, the less chance of cure... How to deal with the disease in the greenhouse and in the open field, we will tell you in more detail.

Chemicals

In specialized stores for summer residents there are many chemicals to combat late blight. But they should be resorted to with caution and when it is impossible to fight with softer means. After application, do not eat the fruit for a month in order to avoid poisoning.

The most effective remedies:

1. "HOM" - a preparation with fungicidal action. Refers to contact pesticides of inorganic origin. Used for spraying. To do this, 40 g of the drug is diluted in 100 ml of water, and then, constantly stirring, bring water to 10 liters.
2. "Oxyhom" (copper oxychloride + oxadixyl) - contact-systemic fungicide against late blight. Dilute 1 package (4 g) in 2 liters of water. Plants are sprayed as needed up to three times with an interval of 10-14 days.

Biological methods

Biological preparations are milder in their effect on the environment and humans. However, they are not as active against fungi.

Treatment is carried out at the initial stages of the disease:

1. «Fitosporin-M " - biofungicide in the form of a dark brown paste, liquid or powder. In horticulture, powder or paste is used. For spraying, dilute 10 g of powder in 5 liters of water or 3 tsp. paste in 10 liters of water.
2. Copper sulfate. Good for spraying. Enough 2 tbsp. l. 10 liters of warm water.

Folk remedies

If it turned out to identify the first signs of late blight, folk methods will also cope with the onset of the disease.

They are completely safe:

1. Yeast. 100 g of yeast is diluted in 10 liters of warm water and the affected plants are watered with the resulting solution.
2. Garlic and potassium permanganate.Grind 100 g of garlic into gruel, pour a glass of water and leave to brew for a day. After the tincture is diluted in 10 liters of water and 1 g of potassium permanganate is added. The affected plants are sprayed with the resulting solution every 10 days until the ovary is formed.
3. Wood ash. A week after planting the seedlings, but before the fruit ovary, the aisles are sprinkled with ash between watering plants, leaving time for the ash to absorb excess liquid.
4. Milk serum... Dilute whey from sour milk with water in equal proportions and spray the seedlings with the resulting solution in July.
5. Table salt. Salt is taken simple, large, not extra. Dilute 1 glass of salt in 10 liters of water and spray the green fruits once a month.

How to cultivate the land after infected cucumbers

After harvesting, even with the slightest signs of disease, the soil is disinfected. Fungal spores have been doing well in the ground for years.

In the fall, after all the bushes have been removed, they begin to process the soil in any of the following ways:

• the beds are dug up and watered with a solution of copper sulfate;
• 10 g of "Fitosporin" is dissolved in 1 liter of warm water and the beds are fertilized;
• water the soil with a solution of potassium permanganate - 2 g of substance per 10 liters of water;
• digging up the soil with wood ash.

The greenhouse itself is not disregarded:

• if possible, the structure of the greenhouse (greenhouse) is treated with a steam cleaner;
• washed with "Pharmayod";
• remove the top layer of soil in the greenhouse and replace it with a new one;
• sow white mustard and dig up the ground before flowering, burying the mustard stalks inside the garden bed.

Can contaminated cucumbers be eaten

If the appearance allows the fruit to be eaten, this does not pose a danger to humans. However, such cucumbers have an unpresentable appearance and unimportant taste. This is what repels them from using them for food.

It is not worth preserving cucumbers infected with late blight. Banks will not stand for a long time.

Prevention

Subject to a few rules, the disease will not appear at the summer cottage:

• alternate the landing site;
• plant varieties that have strong immunity to late blight;
• ventilate the greenhouse regularly;
• avoid waterlogging of the beds;
• burn infected bushes, do not use as compost;
• feed seedlings with potassium-phosphorus fertilizers;
• disinfect seeds before planting by soaking in a weak solution of potassium permanganate.

Conclusion

In the fight against late blight, the most important thing is to be on time. Carefully monitor the condition of the leaves and ovary, and at the slightest suspicion of late blight, start treatment, avoiding the aggravation of the situation.