Cucumber is one of the most common vegetables growing in areas of almost every gardener. In general, the agricultural technology of Zelentsy does not look complicated, the main thing is to monitor the condition of plants and protect them from diseases and pests in a timely manner. One of the most dangerous diseases is white rot. What is it, what are the symptoms of the disease and how to save cucumber plantings, read on.

Disease danger

White rot is a type of fungal infection. Its causative agent is sclerotia fungi, hence another name for the disease - sclerotinia. Due to the fact that the disease is quite common, and fungi affect the culture with lightning speed, each gardener should study the symptoms, control measures and the causes of such an unpleasant phenomenon. A neglect of the sick state of cucumbers and a slowdown in the treatment process is fraught not only with loss of yield, but also with the death of plants.

The dangers of sclerotinia are as follows:

1. Fungal spores are quite tenacious, and can be in the ground for a long time.
2. White rot is able to affect absolutely all parts of the plant: foliage, shoots, fruits, stems and rhizome.
3. Both young bushes and even seedlings, as well as adult plants at the fruiting stage can get sclerotinia.
4. Fungal spores are quickly spread to neighboring bushes, especially if the planting pattern was violated and cucumber plants were planted quite densely.
5. Sclerotinia can be caused by greenhouses growing in a greenhouse, as well as those planted in the open air.

Did you know? July 27 is considered International Cucumber Day.

Symptoms of white rot on cucumbers

White rot on cucumber plants can be recognized by characteristic signs, which include:

1. The occurrence of multiple white spots, like cotton wool, that form on different parts of the bush.
2. The ripe, watery state of the parts affected by the fungus.
3. The appearance of mucous growths dripping on neighboring bushes.
4. The formation of a white flaky plaque on the foci of infection.
5. Withering and dying of cucumber tops.
6. The formation of black sclerotia - accumulation of fungal spores, which is especially noticeable in sections.

Varieties of rot

In addition to white, cucumbers can also suffer from gray, stem and root rot, so the gardener should always be vigilant in order to begin treatment of greenhouses for these diseases in a timely manner.

Gray rot

A widespread disease that affects mainly greenhouse greenhouses is much less common in open ground conditions. The source of the disease is pathogenic fungi, which can enter the plant from the soil, greenhouse structures and plant debris. Most often, it enters the bushes through microcracks and pistils of flowers.

The disease is easily recognized by the characteristic symptoms:

1. Formation on stems and shoots of culture of shapeless gray spots covered with mucus.
2. Spread stains on foliage and cover them with fluffy coating.
3. Rotting of infected parts of a plant.

The main causes of gray rot:

• non-compliance with the rules of planting bushes;
• watering plants with cold water;
• sharp cooling;
• excessive humidity in the greenhouse;
• lack of ventilation.

To eliminate gray rot will help spraying with solutions of "Fitosporin", "Gamair", "Planriz", "Alirin B", "Trichodermin", "Bayleton", "Euparen".

Important! It is necessary to process both sick and healthy bushes, as well as crops growing with cucumbers in the same greenhouse.

Stem and root rot (Fusarium)

Stem and root rot are diseases caused by phytopathogenic fungi that live both in greenhouse conditions and in open ground.

The main factors causing the disease:

• use of cold irrigation water;
• excessive moisture and fertilizer;
• use of contaminated soil and seeds;
• sharp cooling.

Fungi get into the plant through the roots - they begin to rot. Outwardly, this is manifested first by the withering of the cucumber tops, and soon the entire bush: it takes on the form of a plant that has been suffering from drought for a long time. The next stage after withering is finding the root neck of a pink color and its rapid decay. Since the roots of the plant also rot, it soon dies.

To eliminate fusarium, plantings need to be treated with the preparations "Maxim Dachnik", "Previkur", "Gamair", "Trichodermin", "Pseudobacterin", "Baktafit", "Planriz".

Important! Too often, cucumber bushes die due to an untimely definition of the disease, since the roots that are hidden underground are initially affected. Therefore, if you have even the slightest suspicion about the appearance of fusarium on your greens, immediately proceed to the fight.

Reasons for the appearance

Any disease is easier to foresee and prevent than to get rid of it later. In order not to allow white rot to your cucumbers, it is worth studying the causes of its appearance.

What factors contribute to the emergence

It is very easy to plant the disease for cucumbers: sclerotia can get to the culture with irrigation water, when the soil is planted under the plantings with fresh soil, by using tools that previously treated the infected areas. Another factor contributing to the appearance of sclerotia is the wind: it is able to carry spores of the fungus over a long distance. And in order for white rot to spread en masse in all the bushes, just one argument is enough.

Processing cucumber bushes must be done carefully and carefully, being careful not to damage the plants. After all, it is through cracks and damage of a mechanical nature that spores get inside.

Did you know? Spikes on cucumbers are needed to bring out excess moisture. Early in the morning, a dew drop appears from each spike.

Conditions for the development of rot

The lightning-fast development of white rot occurs under the following conditions:

1. High humidity in the greenhouse. Experienced gardeners advise regularly to ventilate the greenhouse and take care of good ventilation. In the open ground, the ideal period for hitting the bushes with the disease is long rains.
2. Low temperature. If greenhouses grow in a greenhouse, temperature indicators should not fall below + 20 ° C, and when grown in open ground, ideal temperature indicators are + 20 ... + 22 ° C.
3. Use of cold irrigation water, especially during hot weather. This creates ideal conditions for the germination of fungal spores.
4. Thickened plantings that retain moisture prevent ventilation and soil warming.
5. Neglect of timely pruning of bushes, which leads to their thickening.
6. Seeding to Zelentsy culture-compactors (dill, parsley, salads).

Important! Even if there was only a small speck of white rot on the cucumber fruit, it is impossible to eat such a vegetable: it loses edibility, acquiring a bitter taste, becomes soft and becomes covered with mucus.

How to deal with white rot

The fight against sclerotinia must be carried out by an integrated method, since the use of one method of control may not give an effective result.

Agrotechnical events

The main measure is about pruning, especially well-branched cucumber varieties. It is a mistake to assume that this procedure is aimed only at increasing the fruiting of the crop (the bush does not spend strength, nutrients and energy on the development of tops, but exclusively on the crop). Among the main goals of pruning is to reduce thickening, and, accordingly, the risk of incidence of bushes, increase fresh air and improve the ventilation of plantings of cucumbers.

Video: Gray and white rot of cucumbers

The first cucumber pruning is carried out after the seedlings reach a length of 5-6 cm. The central shoot left for growth is tied to the greenhouse ceiling using twine. After he reaches the ceiling, he is lowered down and tied again.

After the appearance of 5-7 leaves on the seedling, they trim the lateral foliage.

The length of the side shoots should not exceed 3-5 knots. After fruiting begins, the formation of the bush should begin, by directing all of its shoots into the row. Shoots that go beyond the boundaries of the row must be cut off, even if rich ovaries are formed on them.

Important! Agro-technical measures to prevent the appearance of white rot include compliance with crop rotation rules and timely cleaning of the remains of precursor plants from the site.

Fungicides

For the treatment of cucumbers for sclerotinia, it is advisable to use preparations containing copper. So, in case of damage to the ground part, it is recommended to spray the bushes with a Bordeaux mixture, as well as with a solution of Abiga-Peak, Ordana, Planriza, Alirina-B and Gamair. If the roots are affected, then the plants need to be watered with the listed drugs. The working solution is prepared strictly according to the instructions.

A single treatment will not be effective - it needs to be repeated 2-3 times, observing a ten-day interval. In this case, you must remember about the ban on eating cucumbers for 14 days after treatment.

During processing, it is necessary to remove damaged parts of the bushes.

Folk remedies

Particularly effective at the initial stage of the disease:

1. Milk iodine solution. To prepare it, you will need 1 liter of milk, 10 liters of water and 10 g of alcoholic iodine solution. To prevent the product from draining from the plant, liquid soap (40 ml) or grated solid soap (10 g) is added to it.
2. Soap paste with ash. It is prepared by mixing ash and ground soap in equal proportions. A little water is added to the mixture to make something like a thick paste. Such a drug lubricates the places of slices of diseased mustaches and stepsons, as well as wounds formed after removal of sclerotia.
3. A solution of soda with manganese. In 10 l of water is dissolved in 8 tbsp. l soda and potassium permanganate. To the resulting solution add 1 tbsp. chopped laundry soap, and spray the mixture with bushes.

Important! The treatment of plants with chemical or folk preparations should be accompanied by phosphorus-potassium fertilizing, which is necessary for the tissues to gain strength and resistance to infection attacks.

Disease prevention

A gardener growing cucumbers should organize the following preventive measures against sclerotinia:

1. Ventilate the greenhouse regularly and ensure that the air humidity does not exceed 80–85%.
2. Timely remove the tissue of the bush damaged by the disease and disinfect the wounds obtained with the soap and ash paste described above.
3. Prevent waterlogging of the soil under the bushes.
4. Monitor the temperature of irrigation water: it should be warm.
5. To process the greenhouse before planting cucumbers.
6. To disinfect the soil in which greens will grow, as well as to disinfect the seed.

Make sure that the predecessors of cucumbers are not celery or parsley, which are often affected by sclerotinia.

Which varieties are most susceptible to disease

The most resistant varieties to white rot are Zozulya, Superior Telegraph, Claudia, Connie, Sport Resist. Such varieties as Graceful, Swallowtail, Emerald, Regia, Farmer and others are more actively exposed to sclerotinia.

As you can see, in order to get a good crop of cucumbers, you need to protect the bushes of the culture from diseases, in particular, from sclerotinia. Neglecting the symptoms of white rot can lead to the death of cucumber plants, so if you notice that the tops of the bushes have begun to fade, immediately proceed with measures to combat sclerotinia.