Why does gray rot appear on cucumbers and how to deal with it

Ideal not only in appearance but also in taste, cucumbers are a reality that greenhouses have given us. But the artificially created climate is ideal not only for the growth of beds, but also for the development of various bacteria. Fungal diseases affect many cultures, and cucumbers are no exception. Today we will figure out what gray rot on cucumbers is and how to deal with it.

Gray rot on cucumbers and how to deal with it

What is gray rot

To combat the disease, it is necessary to correctly diagnose. Consider the characteristic features. Gray rot is a common bacterial infection. The culprit of her appearance is Botrytis cinerea. It affects leaves and fruits, covering them with a plentiful gray coating. Affected areas of the plant actively rot, and when the stem is infected, the entire bush soon dies.

Light brown blurry spots on cucumber leaves are the first signs of infection.

Further, the gray rot begins to hit the fruit, covering it with spots. When completely defeated by spores, the fetus becomes very soft and watery, covered with a gray fluff. The insidiousness of this disease is that it very quickly infects neighboring crops, subsequently destroying them.

Reasons for the appearance

Gray rot on cucumbers in a greenhouse can appear for a number of reasons:

Temperature violation

Sudden changes in temperature always adversely affect plant growth. A decrease in immunity exposes a seedling to a fungal infection. Therefore, on average, the air temperature should be kept from 22 to 28 degrees during the day and from 18 to 22 degrees at night. Overheating is considered to be a temperature above 30 degrees during the day and 23-24 at night, which provokes accelerated aging of the plant. If the temperature drops to 8 degrees Celsius for more than a day, irreversible disturbances begin in growth.

Wrong watering

Cucumbers are poured with settled water at room temperature under the root using a watering can with a spray. At air temperatures above 25 degrees, it is necessary to begin daily sprinkling. But it is worth observing the measure in the amount of water, since excessive moisture provokes decay of the plant. The soil should be moist, not wet.

Affection for one place

Cucumbers are strictly not recommended to be planted every year in the same place. This depletes the soil, spreading the disease to all subsequent crops. To get a good harvest, you can plant cucumbers in place of cabbage, tomatoes or potatoes.

Unregulated Humidity

The threat for sowing is both a lack of moisture, and its excess. In the seedling period, the air humidity necessary for cucumbers is 70-75 percent, with a usual relative humidity of 85-95 percent. As for the soil, before flowering, the moisture should be moderate, and after rising to 80%.

Excess fertilizer

Never overfeed a plant with fertilizers. First of all, it concerns substances containing nitrogen. Moderate top dressing takes place in four stages: 1 - 15 days after planting, 2 - when flowering begins, 3 - during fruiting, 4 - near the end of the fruiting period.

Lack of ventilation

Regular ventilation is required.

Without ventilation, moisture will increase in the greenhouse, which is fraught with the onset of decay. To provide ventilation in the greenhouse, it is enough to leave the door open for 2-3 minutes once a day.


Even with a small area, it is recommended to plant crops at least at the minimum necessary distance from each other in order to slow down possible infection. Optimal for this type of plant is the distance between the bunches of 15-20 cm.

Disinfecting disinfection

You always need to be responsive to soil decontamination in the greenhouse.

For this, formalin, fungicides or pesticides can be used, for which dust is added to the beds.

If precautionary measures are not followed, the above factors can cause the onset of the disease. And as you know, to conduct the treatment itself is much more difficult than prevention.

Methods of struggle

The fungus is able to destroy your crop in the shortest possible time, and therefore you need to master the methods of dealing with this disease in advance. When conducting prophylaxis, cucumbers can be made resistant to spore infection. But when the first signs of the disease appear, it is immediately worth starting treatment for your garden.

Watering stops immediately and all damaged sheets are removed. Then carefully inspect the stem: if it is slightly damaged, it is enough to sprinkle it with lime, if it is strong, it is better to cut it immediately, not giving in to treatment, and treat the sections with a solution of copper sulfate. When the fruits are already damaged, fight late, they need to be removed, and then treat the plant with special means

Care products

  1. For dusting, a dry mixture of a teaspoon of copper sulfate and a glass of wood ash is suitable. You can also use the option with the addition of a glass of chalk.
  2. Common purchases: Rovral, Khom, Bayleton, etc.
  3. Bordeaux liquid is used in a proportion of 20 grams of copper sulfate per five liters of water.
  4. You can treat the plant with a five-liter solution with the addition of five grams of vitriol, 5 grams of urea and half a gram of sulfur zinc.
  5. A proven means of control - chalk and water in a ratio of one to one.

How to prevent the disease

Given the above factors for the appearance of infection, a number of basic requirements for the care of the garden can be distinguished. Be sure to purchase seeds in specialized stores and disinfect before planting. Properly feed, ventilate and water.

Consider crop rotation, making room for cucumbers. We advise planting land after cucumbers with marigold flowers or mustard. This will help to destroy the spores of rot in the soil. And also thin out the bushes, as the lush plants touch each other, transmitting more likely fungal spores.


Cucumber is a popular vegetable that takes its due place in the life of every person in any corner of the Earth. It consists of 95 percent water, because it perfectly removes toxins, which also contributes to weight loss. Helps establish the functioning of organs with kidney stones, maintain sugar levels, and improve bowel function.

Cucumbers are rich in B vitamins, vitamin C, iron (purifies the blood), magnesium and many other useful substances. Often this vegetable is used for cosmetic purposes. Face masks can refresh the skin, giving it a tone, and hair masks will help strengthen your hair and remove excess fat.

Agree, it is very unfortunate to lose such a healthy crop because of your negligence. Therefore, be vigilant and protect your greenhouse garden.


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