What to do if there are rusty spots on the leaves of cucumbers
Rusty spots on cucumber leaves should not be ignored. A briskly green cucumber garden can turn into a sad sight in a few days - goodbye to the dream of crispy cucumbers. Brown or dark yellow spots that appear on the leaves may be sunburn marks. Burns are common, but not worth fearing. The burnt plants will move away and continue to grow further, you just need to gently water the bushes, not getting water on the leaves. The danger is a fungal infection, from which rust appears on cucumbers.
Why are rusty spots visible on cucumber leaves?
Spores of various fungi are carried by the wind, accumulate on weed leaves, and live in the upper layer of the soil. A plant with strong immunity, with good care and a favorable microclimate, copes with infection.
Various factors weaken cucumbers:
- cold weather;
- frequent rains;
- lack of sunlight;
- the difference between night and day temperatures.
Infection (bacteria, fungus, virus) under unfavorable conditions causes diseases, the symptom of which is brown spots on the leaves.
Consider several diseases common in open ground and greenhouses: cladosporium, peronosporosis, anthracnose.
Diseases
Most plants infected with the fungus are covered with dry, brown leaves in the latter stages of the disease. The first symptoms of almost all diseases on cucumbers look like white, yellow, brown spots on the leaves.
Consider only those diseases in which, due to rust on the leaves of the whip, they die, lag behind in development, and stop bearing fruit.
Cladosporium
Otherwise, this disease is called brown olive spot. The fungus affects almost all parts of the plant:
- leaves;
- whips;
- fruit.
At the initial stage, small red (olive) spots are visible on the leaves and stems. Over time, the spots darken, resemble a burn, gradually holes form in their place. The spores settle on the fruit, and brown dents form on them.
Cladosporiosis usually affects cucumber whips in August with sharp fluctuations in daily temperatures and during the period of prolonged rains.
Experienced gardeners offer the following scheme of actions to get rid of the rusty spots that appear:
- The fungus grows better in a humid environment, so the first step is to stop watering the bushes. The pause in watering should last at least a week.
- At an average daily temperature of 15 - 16 ° C, cover the cucumber ridge with spunbond or other covering material at night, remove the cover during the day.
- Carry out the treatment of plants from the fungus.
Treat bushes with one of the drugs:
- Bordeaux liquid, concentration 1%;
- copper oxychloride, solution 0.4%;
- "Oxyhom" in the amount of 20 g per 10 l bucket, the water should be warm.
Peronosporosis
More often this disease of cucumbers is called downy mildew. Yellow spots form on the surface of the leaves, their size grows every day, the color of the spots changes from a dark yellow shade to red. Leaves affected by the fungus wilt and dry. Bushes may die.
How to deal with the problem? Having noticed signs of downy mildew, you need to temporarily abandon fertilizers and watering. Treat leaves and stems for fungal infections without waiting for them to spread to other plants. Drugs used for treatment:
- copper oxychloride;
- bordeaux liquid;
- "Ridomil";
- "Ordan".
In the open ground, cover the treated plants at night with a film (covering cloth), in the greenhouse, raise the night temperature to 16 ° C.
Anthracnose
People call anthracnose copperhead. The appearance of rusty spots on the leaves signals the onset of the disease. The symptoms are recognizable - a plant with anthracnose is easy to recognize:
- multiple brown spots on the leaves, which seem to be burned;
- dry leaves;
- brown ulcers on fruits.
Gardeners believe that the main cause of the disease is contaminated seed. The spread of anthracnose occurs when collecting seeds from diseased plants. The main factor leading to anthracnose is cold watering.
Processing alone will not be enough. For the first time to eliminate the reasons, use Bordeaux liquid (1%). All damaged parts of the plant are regularly removed and sprayed with copper sulfate (0.5%). We save ourselves from anthracnose in different ways. It is permissible to use home recipes for fungal diseases.
How to treat a diseased plant? It is better to prepare a working onion solution in an enamel or iron bucket. Hot water is needed for infusion. A 10 liter bucket of water will take 2 tbsp. l. (50 g) chopped onion skins. Bring a bucket of water and onion skins to a boil and remove from heat. The working solution should be prepared within a week. One cucumber bush will take 1 liter of liquid fertilizer. If home control measures are ineffective, resort to the help of a fungicide.
Prevention
Knowing why rust appears on cucumbers, you can take measures to eliminate these prerequisites by fighting the fungus in advance. Start prevention from the first stage - sowing seeds. Protect the seeds from the fungus with a manganese solution. Soak them in the pink solution for at least 15 minutes.
How to deal with the problem? Disinfect the planting substrate when propagating bushes using seedlings:
- Method one - warm up the soil for 25 minutes at a temperature of 100 ° C.
- The second way is to spill it with boiling water.
- The third way is to shed Fitosporin.
Further preventive measures concern the vegetable garden (greenhouse). Alternate crops in the garden. Do not plant the crop in one place. Poor predecessors of cucumber are squash and pumpkin, after which pathogens that are dangerous for cucumbers accumulate in the soil. In autumn, we get rid of the remnants of vegetables and weeds in the garden. 2 weeks before planting the beds, we spill Fungicide or a pink solution of manganese.
We process the plantings during the growth, flowering of the culture with Bordeaux liquid at least 4 times. Remove the rusty cucumber leaves, lubricate the cut with a solution of copper sulfate.
The loss of yield from rust can be noticeable - up to 30%. But now we know what to do as soon as signs of pathology appear: we urgently begin to treat the diseased plant.
