When growing cucumbers, farmers often encounter various diseases of this crop.
One of the most dangerous is considered to be fusarium wilt, which can lead to the death of the plant.
What is Fusarium, what is it manifested and how to deal with it.
What is dangerous and where does it come from
The main cause of leaf wilting is overheating of the plant; they begin to wilt at ambient temperatures above 38ºС. And overheating of the soil above 25ºС can lead to the destruction of the bush. 
Another reason is the defeat of spores of the fungus Verticillium or Fusarium oxysporum. Such wilting is called fusarium or tracheomycotic. In this case, not only the leaves are subject to fading, but also the entire bush.
Spores enter the plant through a weak root system and injured leaves. Fusarium develops faster at low temperatures, excessive watering, and also in greenhouse conditions due to the fact that in greenhouses the soil is often not treated.
Important! Sometimes the spores of the fungus get to the plants along with the water from the natural reservoirs, if they are irrigated from such.The danger of this disease is that the earlier the infection occurred, the higher the harm done in the future. And also in the fact that in the early stages it is impossible to identify it, it appears only on adult plants during the flowering period.
The main cause of this disease is infected seeds or seedlings. The soil can also cause infection, but mainly in cases of greenhouse cultivation of cucumbers or when they are grown in one area for several years in a row. 
Signs of appearance
When fusarium affects the vascular system of the bush. On the cut of leaves and stems visible dark vessels. At the slightest suspicion of a disease, a cross section is made and the plant is examined for the presence of a brown vascular grid.
Check out such varieties of cucumbers as the "Real Colonel", "Masha f1", "Competitor", "Zozulya f1", "Nezhinsky", "German f1", "Courage".Fusarium can also be determined by the rotting of the radical neck and root. In these places, the stem grows brown and thinner, and the leaves begin to turn yellow. The plant begins to wither and dies. It also blooms poorly, and after flowering, the ovary dies out.
Preventive measures
Fusarium wilting of cucumbers is dangerous because there is no 100% effective method of struggle against it, so when asked how to fight it, the most rational approach would be to prevent infection through preventive measures. 
Since the spores of fungi enter the plant through the soil, the main preventive measure is soil treatment. It is disinfected with boiling water or green manure, i.e. green fertilizers obtained from mustard, lupine.
It is necessary to observe the temperature regime, not to overwet the soil. Cucumber seedlings are hardened in greenhouses, so that the leaves of adult plants are less prone to wilting.
Did you know? Word "cucumber" derived from ancient greek "aguros"that means unripe, immature.
In addition, it is imperative to remove the affected bushes, as well as to choose disease-resistant varieties for planting.
Agrotechnical receptions
To prevent the development of the withering of cucumbers, it is necessary to observe the technology of preparing substrates and observe the terms of their use. 
It is also recommended to change the substrate from time to time for the subsequent cultivation of crops.
To strengthen and improve cucumbers, compost or humus is introduced into the soil. Loosen the soil to saturate the roots with oxygen. Drainage systems should be monitored with drip irrigation, avoiding stagnant moisture.
Did you know? Spines on cucumbers are designed to drain excess moisture from the fruit. In the mornings they can see dew drops.Plucking bushes and timely harvesting reduces the load on the root system, as a result of which it becomes more resistant to diseases.
Preparations from the withering of cucumbers
The fight against the withering of cucumbers in many cases is not sufficiently effective, since the causative agent of the disease exhibits high resistance. Nevertheless, consider the most popular and effective drugs. 
Biologics
Among biopreparations, the drug Trichodermin, created on the basis of Trichoderma strains, is the most effective in the fight against fusarium. To improve the effectiveness of the drug make a couple of days before transplanting in a pre-moistened soil.
Next, hold the spraying of the soil and stems suspension. Other effective drugs in this group are Baktofit, Trihofit and Planriz. As a preventive measure, they spray the seedlings and the substrate.
Learn how to deal with diseases and pests of cucumbers, especially with midges, powdery mildew.
Chemical
Fungicides for the most part have little effect on the fungus. During the experiments, a satisfactory result was given by the drug "Fundazol". They are treated with seeds before planting.
Also, after sowing seeds, it is recommended to water the soil with a solution of Previkur Energy (concentration of 0.15%). 
In the early stages of the detection of a disease, Quadris, Gymnast, Acrobat MC, and Maxim can be used to treat bushes. To increase resistance to fading, seeds and seedlings are treated with Humisol.
Folk
With fusarium wrestling is carried out by popular methods. One of them is spraying with whey solution. 4 liters of serum are added to 10 liters of water.
Important! Copper sulphate can be added to this solution (1.5 tsp.).
Is it possible to fight in the active phase of development
Unfortunately, in the advanced stage it is impossible to fight this disease. Affected bushes must be removed and burned. They cannot be used as compost. Neighboring plants are processed by one of the above methods. 
Resistant varieties
The most effective preventive measure is the choice of cucumber varieties that are resistant to diseases. These are predominantly hybrid varieties labeled with F1. Here is a list of the most popular hybrids:
- Ryabinushka;
- Dunyasha;
- Ideal;
- Zhukovsky;
- Vityaz;
- Caprice;
- Sir;
- Bunny.
