What is fusarium wilting of cucumbers and how to treat it
Fusarium wilting of cucumbers is one of the most harmful and aggressive diseases that actively affect large areas of cultivated plants. Even 20 years ago, fusarium disease attacked mainly grain crops, less often other types of garden crops suffered from this. The trend is rapidly changing. Fusarium and cucumbers are not spared. Resistant to almost all fungicides. Therefore, it is very important to know the symptoms and causes of Fusarium wilt of cucumbers, how to deal with it, what will help preserve the plants, how to prevent infection, what to do if symptoms of the disease are found on the bushes.
Fusarium wilting
Characteristics of the disease
The causative agent is fungal bacteria, persistent and fast growing, which belong to the genus Fusarium Link. The most common is especially toxic F. graminearum or F. solani (Mart). Distributed in many regions. Active parasitic fungi tend to infect virtually all types of garden crops.
These types of bacteria spread easily, retain their viability in the soil for several years. They can be transferred from plant to plant by wind, water. Fungal spores penetrate the root system. High temperatures and overheating of the soil stimulate the development of the disease. Fungal diseases are most active in favorable conditions for them. The disease attacks weakened plants especially quickly.
Causes
The reasons for this deterioration in the persistence of cucumbers are as follows:
- poor quality agricultural technology;
- soils poor in microelements;
- sudden changes in temperature;
- damage by pests;
- high humidity of air or soil.
Excessive watering, stagnation of water in the aisles will negatively affect the health of vegetable crops, and will provoke a decrease in disease resistance.
In a special risk group are varieties grown in greenhouses. Since the soil in greenhouses is rarely disinfected, and the temperature and moisture level are favorable for the life of Fusarium Link. When infected, the crop of greenhouse cucumbers dies very quickly.
Symptoms
It is difficult to detect infection of young plants. In the initial period, fusarium wilting may not appear. The asymptomatic course of the disease lasts a couple of weeks. When diagnosing young bushes, the stem cut should be examined. In the presence of the disease, darkening of the transport capillaries of the cucumber lash will be observed. In young plants, root rot is the first sign. Visually, it will look like a darkening of a part of the stem and its gradual thinning.
The main symptoms are:
- wilting of the lower single leaves, and gradually all;
- changes in pigmentation of the green part of the bush (pallor, yellowish spots);
- exit to the surface of the stem of conidia (pink bloom);
- darkening of the stem, its cracking, traces of rot.
When the disease progresses, other symptoms begin to appear, which indicate the intensive development of fusarium, the movement of bacteria through the vascular system of the cucumber. The gradual advancement of Fusarium through the plant will be accompanied by wilting along the entire growth line. Fusarium fungi, like any other living organism, secrete traces of vital activity, and it is they that are toxic and, in addition to blocking the vascular system, the process of rotting roots, as well as other parts of the bush, is added. As a result, necrosis (death) of vegetative organs and complete death of the plant.
Preventive measures
In the case of such a disease, infection prevention and preventive measures are the ideal treatment. For this, there are a number of agrotechnical measures that will maximally protect cucumbers from infection.
Preventive measures will help preserve the harvest
Planting healthy seedlings and non-contaminated seeds will be an important and indispensable preventive measure. Processed seeds can be easily purchased in specialized stores. As for the seedlings, the best choice would be self-grown in compliance with the technology.
The next step is to cultivate the soil in a greenhouse or in a garden bed intended for planting cucumbers. There are different methods of disinfection and preventive measures:
- thermal;
- biological;
- mechanical;
- chemical.
Thermal is the treatment of the soil with boiling water, suitable for small beds and small greenhouses. The biological, laborious method, takes time and effort. Such disinfection is carried out by removing 20-25 cm of soil, which is sent to compost, transferring the soil with balls of manure and keeping it for 2-3 years. Mechanical is similar to biological, in this method the top layer is removed and replaced with a fresh, uninfected one. The most optimal and fastest remains chemical, with the help of a wide range of disinfectants, soil is treated.
Well, the correct agricultural technology will be important so that the plants grow strong and resistant. Moderate watering, timely feeding and pest control, as well as the use of covering material in cases of sharp drops in temperature.
Treatment
Fusarium disease refers to those diseases that are difficult to treat for several reasons:
- late diagnosis and definition of the disease;
- infection comes from the root system.
The first thing to do when identifying diseased plants is to remove them from the garden and burn them to prevent contamination of healthy plants; in no case should the affected plant be left in the garden or in the compost pit.
The next step will be treatment with biological or chemical agents for the prevention and control of fusarium.
Biological agents
The biological product Trichodermin has proven itself well in the fight and prevention of fusarium in cucumbers.
The product is made on the basis of a laboratory-derived trichoderma strain. Trichoderma is a unicellular organism of the genus hyphomycetes. An organism that parasitizes certain types of fungus and thereby destroys it. It is this characteristic property of Trichoderma that makes it possible to use it in the fight against fusarium in cucumbers. Absolutely safe for cucumbers and the environment.
The drug is used to spray the stems and leaves of plants that are at risk of infection. Trichodermin is also used for soil cultivation 2 days before transplanting.
Similar analogs are Baktofit, Trichophyte, Planriz. They have also been used successfully to stop the spread of fusarium wilt in cucumbers.
Chemicals
The use of chemicals for the treatment and prevention of fusarium wilting also takes place in agricultural technology. Most fungicides are not effective enough to fully combat the disease.A large number of chemicals (fungicides) have been produced that do well in the fight against fusarium on cereals, cereals and ornamental crops. There are not a large number of effective fungicides used on crops of the pumpkin family, and their effectiveness is not high enough to combat fusarium in the active stage.
Based on the research results, Fundazol has shown itself to be effective. The drug is used for dressing seeds before planting, and in case of illness, cucumber bushes are added with a solution. The period of action of Fundazol's protection is two to three weeks. A group of benzimidazole preparations has shown themselves to be effective in combating wilting.
Fusarium resistant varieties
The modern seed market allows you to choose varieties that are resistant to this type of disease, which will make it easier for the gardener.
Several varieties that have quality characteristics and are especially resistant to fungal diseases:
- Vocals are resistant to fungal diseases, high humidity, insufficient lighting, temperature changes. Parthenocarpic, universal, high-yielding.
- Raphael is a self-pollinated, vigorous hybrid, resistant to root rot with smooth cylindrical fruits, good taste.
- Obskiy is a medium-sized hybrid resistant to peronosporosis, fusarium, bacteriosis and sudden temperature changes, the taste is wonderful.
- Dvoryansky is a mid-early pollinated hybrid with an early type of flowering, resistant to anthracnose, ascochitosis, cladosporosis, fusarium, bacteriosis and viral infections.
Conclusion
Despite the complexity and widespread occurrence of this type of disease, there are ways to grow a high-quality crop with minimal losses. The main and most effective way to combat fusarium wilting when growing cucumber is preventive measures, disinfection and soil treatment. And the main thing is the correct cultivation technology and careful plant care. Strong and healthy bushes, rarely susceptible to fungal diseases.