Content
Growing cucumbers in a greenhouse allows you to get a harvest much earlier than in open ground. But this process is fraught with certain difficulties. After all, greenhouse conditions are an ideal environment for the proliferation of pathogenic microflora. And if certain preventive measures are not followed, gray rot appears on cucumbers. If the fight against this fungal disease is not started in a timely manner, the harvest will be very modest.
Gray mold can lead to the death of all plants in a greenhouse
How dangerous is the disease?
Gray rot is a dangerous fungal disease that affects many vegetable crops, including cucumbers. In greenhouse conditions it progresses especially.
The disease affects leaves, shoots, flowers and fruits of cucumbers. As a result, they rot. In case of massive damage, the plant dies completely. And pathogens spread to all nearby crops in the greenhouse.
Causes of gray rot
Certain conditions are necessary for gray rot to develop.The disease begins to progress at a temperature of +16-18 ° C and high humidity of about 90%. First of all, pathogens attack weakened cucumbers.
Factors contributing to the further spread of gray mold in the greenhouse:
- dense plantings;
- sharp changes between day and night temperatures;
- non-compliance with crop rotation rules;
- watering with cold water;
- excessive moisture;
- high levels of nitrogen in the soil;
- insufficient ventilation of the greenhouse;
- untimely removal of plant residues.
Causative agent of gray mold
The causative agent of gray rot is the fungus Botryotinia fuckeliana. It feeds not only on living cucumber cells, but also on dead organic matter. The causative agent of gray rot overwinters on plant debris in the soil and greenhouse structures. And with the arrival of spring warmth, its life cycle resumes.
The pathogen enters through microwounds on the shoots and leaves of cucumbers. It is also capable of penetrating flowers through the pistils and causing the ovary to rot. Having settled in the tissues of cucumbers, the fungus begins its destructive activity. It releases toxins that cause cell death and disrupts metabolic processes. Subsequently, the affected areas become a breeding ground for the development and reproduction of the fungus. At the end of the growing season of the crop, the pathogen, along with plant debris, enters the soil, where its mycelia and sclerotia overwinter.
Signs of gray rot on cucumbers with photos
The first signs of gray rot damage to cucumbers begin to appear seven days after the pathogen penetrates the plant tissue.It is at this stage of the development of the disease that it is important to promptly identify the lesion and carry out treatment. In this case, the chances of saving the future harvest are quite high.
Since the pathogen overwinters in the soil, the first signs appear in the lower part of the plant
First, you can detect a gray coating on the leaves and at the base of the shoot of cucumbers. As the disease progresses, spots with jagged edges of a yellowish-brown hue appear on the affected areas. Subsequently, they increase in size and merge. As a result, the disease rises up the stem, affecting not only the leaves, but also the flowers and the ovary of cucumbers.
Fungal spores appear on the affected areas, which spread to all crops in the greenhouse. At this stage, it is much more difficult to resist gray rot.
How to deal with gray mold on cucumbers
To combat this disease on cucumbers, comprehensive control measures should be used. Only in this case can the further spread of pathogenic microflora be stopped and the future harvest saved.
Folk remedies
To combat gray mold on cucumbers in a greenhouse, you often have to use folk remedies. Since this crop is characterized by early fruiting, the use of chemicals is not always possible. This control method helps prevent and slow down the development of gray rot.
Effective folk remedies against gray rot on cucumbers in a greenhouse:
- Wood ash. The product must be sprinkled onto the surface of the soil. You should also dust the shoots and leaves of cucumbers with wood ash against gray rot.
- Iodine. Mix 1 liter of milk and ten drops of the main component. Then add 5 liters of water.Spray the cucumbers with the resulting product, spraying it in an even layer on the soil, leaves, and shoots.
- Baking soda. Dissolve 2 tbsp in 5 liters of warm water. l. component. Add 100 g of grated laundry soap and mix thoroughly. Treat cucumbers with the resulting mixture.
- Garlic. To prepare a working solution, you need to grind 200 g of the component and pour in 4 liters of warm water, and then leave for two hours. Treat the soil with the resulting mixture. And then add another 1 liter of water and spray it on the shoots and leaves.
Biological agents
Biological products help to cope with the problem and at the same time grow an environmentally friendly crop of cucumbers. But their disadvantage is that they are not able to penetrate plant tissue and affect the pathogen from the inside. Therefore, their use is justified as a preventive measure and at the initial stage of damage to cucumbers in a greenhouse.
Effective means:
- Trichodermin. One of the most effective remedies that can be used against gray rot. Sold in the form of powder and water emulsion. To treat cucumbers in a greenhouse against gray rot, you can use both forms of the drug. The composition includes spores and mycelium of the antagonist fungus, components for the development of beneficial microflora and a vitamin complex. When beneficial microorganisms enter a plant, they displace pathogens by intensive reproduction. To process cucumbers, you need to prepare a working solution based on this drug. To do this, the aqueous suspension should be diluted with warm water at the rate of 10-100 ml per 10 liters, mixed and left for two hours.When using powder, initially you need to dissolve 10-100 g of the product in 1 liter of water, leave for two hours, and then bring the volume of liquid to the required volume and mix.
Trichodermin is classified as a natural antibiotic.
- Fitosporin-M. A biological product containing beneficial bacteria Bacillus subtilis. During their life, they produce antimicrobial fungicidal proteins. Produced in paste and powder form. Both forms of the drug are suitable for processing cucumbers in a greenhouse. To prepare the working fluid, you need to dissolve 100 g of paste in 200 ml of water, and then 3 tbsp. l. add concentrate to 10 liters of water. When using powder, you need to dilute 10 g of the product per 5 liters of water. After this, the solution must be left for two hours to activate beneficial bacteria. Spray cucumbers three times every 10-15 days.
The active components of Fitosporin-M suppress the development of pathogens
Chemicals
Chemicals should also be used against gray rot on cucumbers. Without fear, they can be used for pre-sowing tillage and spraying of plants at the initial stage of development. Because by the time the crop is harvested, the harmful components have already broken down into safe compounds.
Effective remedies against gray rot on cucumbers:
- Topsin-M.
Topsin-M is available in powder form
- Switch.
The switch stops the growth of mycelium in plant cells
- Maksim.
Maxim should be used for soil cultivation
- Home.
Hom is a copper-containing drug
Agrotechnical techniques
Gray mold can be combated using agrotechnical methods.To do this, it is recommended to lay mulch at the base of cucumbers when growing them in a greenhouse. This will prevent the increase in humidity levels, which is so necessary for the development of pathogens.
If signs of disease appear on cucumbers, cut off all affected areas and burn them. And if the plant dies, dig it up along with a lump of earth on the roots and take it outside the greenhouse. It is also recommended to feed cucumbers with potassium sulphide at the rate of 25 g per 10 liters of water to increase their immunity.
Preventive measures
To avoid having to deal with gray mold later, you must adhere to certain rules of prevention. This cannot completely eliminate the possibility of damage, but it can reduce it to a minimum.
Preventive measures:
- timely removal and burning of plant residues after harvesting;
- compliance with crop rotation;
- planting cucumbers in a greenhouse at a distance of 20-25 cm;
- mandatory tying of shoots to a support;
- pre-sowing treatment of seeds and soil with fungicides;
- regular ventilation of the greenhouse;
- watering with settled water, the temperature of which is not lower than +18 ° C.
Cucumber varieties resistant to gray rot
There are varieties of cucumbers that have increased resistance to gray rot. However, to maintain their high immunity, it is necessary to follow the rules of care in accordance with the requirements of the culture.
Resistant varieties of cucumbers:
- Rowanushka.
Rowanushka is a medium-ripening hybrid
- Ideal.
Ideal is not susceptible to low temperatures
- Zhukovsky.
Zhukovsky fruits do not acquire bitterness due to lack of moisture
- Caprice.
Caprice is characterized by an accelerated growth rate
- Tanechka.
If the harvest is untimely, the fruits of the Tanechka hybrid do not outgrow
Conclusion
Knowing how gray rot appears on cucumbers, you can take measures to protect the plants. To do this, you should not wait until the first signs of damage appear, but rather pay increased attention to prevention. After all, it allows you to prevent the development of pathogenic fungi in the greenhouse and reduces the number of plant treatments during the season. An important role is also played by the choice of cucumber varieties for a greenhouse, which have increased resistance to gray rot, which makes it possible to grow the crop without much difficulty.
