How to treat brown spots on cucumber leaves, control measures
Cultivation of crops is not only about watering and weeding. You should carefully monitor the appearance of plants. The appearance of various spots on cucumbers speaks volumes. It is not so easy to understand the reasons.
How to treat brown spots on cucumber leaves?
It will not be possible to answer this question unequivocally. Since the reason for their appearance is not one. It is necessary to carefully look at the appearance of the spots and determine their features. Only then decide what methods to fix the problem.
Cladosporium
Fungal disease, another name for cucumber olive spot. Rounded spots of an angular shape are formed throughout the sheet. When dry, the structure of the leaf inside the stain is destroyed. The whole plant is covered with ulcers, they have an olive tint. The spot widens markedly already on the 3rd day. The infection affects young fruits, they become crooked and covered with spots.
A favorable environment for the spread of the disease is:
- Rain.
- Cloudy cool weather.
- Sharp jumps in temperature.
- At the end of the growing season, when the nights get colder, a lot of dew falls.
Vendors:
- Wind.
- Water.
- Rain.
The peculiarity of the disease is that the infection persists for a long time in the soil and plant remains.
The spread of the disease can be limited, just follow a few simple steps:
- Cucumbers should not grow in one place more than once every 4 years.
- Watering is carried out only with warm water, at the root.
- Feed the cucumbers in a timely manner.
- Remove all plants and vegetables from the beds without leaving them in the garden.
- Always ventilate when grown in a greenhouse.
If cucumbers have cladosporia, then the bushes should be treated immediately. But first, stop watering for 4–5 days. It is desirable that the temperature is +20 ⁰С, if it is lower, then you can cover the beds with material, and close the greenhouse well at night.
The methods of struggle are varied:
- Spraying the bushes with Bordeaux liquid. Solution at a concentration of 1%.
- 03–04% copper oxychloride solution. They are processed 3-4 times per season, a break of 10-12 days.
- Fumigation with sulfur dioxide for 2 days (in a greenhouse).
- Spraying the bushes with iodine chloride.
- Treatment with serum with water solution 1 * 10.
Ascochitosis
Large brown spots are formed on the leaves of the plant, gray-white spots on the stems. Young ovaries and large cucumbers are affected, as a result of which they rot. The disease arises and develops under adverse weather conditions.
Preventive measures.
- Spraying bushes with infusions of tobacco, tomato and potato tops, onions, garlic.
- Dusting with wood ash.
- For 10 liters of water, 30 drops of iodine, 1 liter of milk and 30 g of soap. Once every 10 days.
If the disease is affected, you should:
- Treat with 1% Bordeaux liquid solution and 0.3% copper oxychloride suspension.
- A weak solution of copper sulfate is prepared. Take 5 g of the substance and dilute with 10 liters of water. 10 g of urea is also added there.
Gray rot
The defeat of this disease is characterized by the appearance of brownish spots on the leaves, covered with a gray bloom. Shoots begin to rot, leaves dry, necrotic spots appear.
Distribution medium:
- Damp cloudy weather.
- High humidity.
- Low temperature.
Bacteria can be spread by:
- Wind.
- Contaminated soil.
Prevention consists of:
- In compliance with crop rotation.
- Planting material processing.
- Removing all plant residues from the beds.
- A selection of disease resistant varieties.
Processing is carried out in several ways. The decision remains with the summer resident, either to use chemicals, or to use folk methods.
Control measures:
- Fungicide treatment.
- Trichodermin, a biochemical control agent.
- 10 liters of water + 300 g of wood ash + 300 g of chalk + 1 teaspoon of copper sulfate. Process 2 plants with this volume.
Anthracnose
The second name is copperhead. Depressions appear on the stems. This prevents nutrients from moving forward. As a result, the plant dries up and dies, while infecting all nearby bushes. The speck that appears on the leaf is yellow with a brown tint.
Favorable conditions for the development of the disease:
- High humidity.
- Heat.
- Lack of potassium and phosphorus.
- The acidity of the soil is increased.
Preventive work:
- Top dressing with complex preparations.
- Control over soil moisture.
- Pest control.
- Treatment with weak fungicide solutions.
- A selection of varieties that are immune to the disease.
- Seed dressing.
How to deal with a developing disease:
- A 1% solution of a suspension of colloidal sulfur is used.
- Also 1% Bordeaux mixture solution.
- 0.5% solution of copper sulfate. After processing, be sure to powder the plants with chalk, coal, lime.
- Preparations "Tsineb", "Tsiram".
Bacteriosis
Holes form on the leaves, and ulcers on the fruits. The disease is bacterial, insect-borne or waterborne. Dark brown spots form on the outside of the leaf. The fruits are deformed. It spreads during periods of high humidity, temperature changes.
What to do to avoid infection:
- Do not plant a crop more than 1 time in 4 years in one place. If necessary, it is required to remove the top layer of soil.
- Treat seeds.
- Remove infected fruits and leaves from plants.
Treatment is carried out with chemicals. Also treated with Bordeaux mixture or copper oxychloride.
General measures to prevent the development of the disease
Nothing helps in this difficult matter as the advice of experienced summer residents who have faced illnesses. General measures for the prevention of all of these and other diseases are to follow simple recommendations.
It is easier to prevent the development of viruses and infections than to treat plants.
Preventive measures:
- First of all, adjust the watering method, it is best to use drip irrigation, or watering directly under the root.
- More attention is paid to soil moisture. Its shortage, like its surplus, leads to the fact that various diseases begin to develop.
- Watering time outdoors in the evening after sunset, in the greenhouse in the morning.
- Compliance with the ventilation regime when grown in greenhouses.
- A culture that grows from year to year in one place is much more susceptible to disease.
- It is better to use complex fertilizing, this will increase the general tone of the bushes and increase resistance.
- When grown in a greenhouse, constant processing and disinfection of the premises is required.
- The tools used in the work are disinfected without fail.
- Temperature for healthy culture development + 20⁰С. When lowering it, a covering material should be used.
Fertilizers
The presence of any external abnormalities in a plant is not always indicative of the development of any disease. Often the reason is the lack of minerals in the soil.
It is required to feed the plant regularly, in addition to the introduction of organic fertilizing, solutions are used that contain potassium and magnesium.
An excess of copper leads to the fact that the plant has brown spots on the leaves, they begin to fall off.
Variety selection
The main advantage of the modern gardener is the abundance of choice of crop varieties. You can choose the characteristics of the species that meet the requirements of the family.
In order not to suffer from constant struggle and carrying out preventive treatments for bushes, you can purchase special varieties. They are most often hybrid, resistant to major diseases. But it should be remembered that collecting seeds on your own will lead nowhere. Since such varieties do not preserve the hereditary genes of their parents.
Fruiting of many species does not depend on climatic characteristics. They set fruit even in unfavorable weather.
The appearance of spots on the leaves of a cucumber indicates that the plant needs something. Before starting treatment for all diseases or starting thoughtlessly feeding the bushes, they understand the reasons for their appearance.
