Why rusty spots appear on cucumber leaves and how to deal with them

In summer, in vegetable gardens, you can often see rusty spots on the leaves of cucumbers. There are many reasons for this phenomenon. Cucumbers are picky plants and need proper care. It is important to properly care for the crop to prevent yellowing of the leaves.

Why rusty spots appear on the leaves and what to do to prevent them from appearing, you will learn from this article. Gardeners will share their personal experience and tell you how to get around the problem and grow cucumbers without loss.

Causes of rusty spots on cucumber leaves

Cucumbers are native to tropical forests, where a humid warm climate reigns. This factor must be taken into account when starting to grow crops in the garden. Violation of habitual growth conditions leads to a variety of problems. One of them is that rusty spots appear on the leaves of cucumbers. There are several reasons for this phenomenon.

Diseases

Why are there rusty spots on the leaves of cucumbers? The first reason is fungal illness, such as cladosporiasis, anthracnose, ascochitis, peronosporiasis.

To determine which disease has attacked the plantation, inspect the leaves:

1. If the spots are light brown on the leaves, and the lower part is covered with cobweb-like mycelium, then this is a lesion cladosporiosis (olive spot). The disease progresses with high humidity and low air temperature. Young shoots and fruits are affected more often.
2. If brown depressed spots appear on the root collar, the plant is ill. anthracnose... The disease affects the leaves - even red spots appear on them. This disease is sometimes called "copperhead". The main reason is the water that gets on the leaves of the plant during watering or rain.
3. In greenhouses often occurs ascochitis (black stem rot). Cucumber stems are covered with large spots, which are green at first. Over time, the spots turn brown, the fruits rot. The ascochitosis fungus does not live in the soil, it multiplies only through the seed.
4. Another disease that affects cucumbers in a greenhouse is angular spotting... Plants are covered with oily green spots. Over time, they acquire a rusty hue, holes appear in the leaves, the fruits become covered with whitish ulcers.
5. Another problem is peronosporosis... It is also called downy mildew. Yellow spots appear on the top of the sheets. Gradually they grow, acquiring a rusty hue, the tops of the cucumbers dries up.

Attention. Fungal diseases develop actively in high humidity and are often transmitted through seed.

Lack of nutrients

Rust on cucumbers can be caused by a lack of nutrients, as this weakens the plant's immune system.

When growing a crop, feed according to the following scheme:

1. After the appearance of the fourth leaf, apply nitrogen fertilizers. For this, ammonium nitrate is suitable. Dilute 2 tbsp. l. saltpeter in 10 liters of water. Water 0.5 liters under the bush.
2. Second top dressing spend after 2 weeks. At this time, the plant is gaining green mass. Take 0.5 kg of yeast, 1 liter of old jam and dilute in a bucket of warm water. Let the solution ferment in a warm place for several hours. For feeding, 1 liter of the mixture is diluted in a bucket of water. Water with 0.5 liters of fertilizer under each bush.
3. During flowering and fruiting, they switch to phosphorus-potassium fertilizers, continuing to apply top dressing every 15 days. You can prepare a mixture in the proportion: 1 tbsp. l.superphosphate, 2 cups of potassium chloride, 0.5 cups of wood ash. Dilute in a bucket of water, pour 0.5 liters under a bush.
4. Organic lovers use humus or compost. You can also use pharmaceutical preparations - brilliant green, hydrogen peroxide. These funds not only nourish the cucumbers, but also serve as antiseptics, protecting plants from diseases.

Attention. Fertilizers are applied after watering so as not to burn the root system.

Pests

Sometimes red spots on cucumbers are caused by a spider mite. This pest appears in hot weather and feeds on the plant cell sap.

To get rid of it will help:

• weeding of beds;
• moistening the beds in hot weather;
• the drug "Fitoverm" with severe damage.

Dry leaves can be caused by melon aphids. It settles on the inside of the leaves, sucking the juice out of them. A solution of baking soda, water and laundry soap (1 tablespoon of soda per 1 liter of water) will help to fight aphids. The soap is used to adhere the solution.

How and what to treat

There are many ways to deal with rust. It is important to remember that fungi thrive in humid environments. In this regard, it is worth taking a number of measures to save cucumbers:

• stop watering for a week;
• when the temperature drops to +15 ° C, cover the beds with oilcloth;
• thin out the beds to improve ventilation;
• lighten the structure of the soil by fertilizing with hydrogen peroxide (dilute 2 tablespoons of peroxide in 1 liter of water and pour 0.5 liters under the bush).

Chemicals

Chemicals will help get rid of rust on the leaves: Bordeaux mixture or copper oxychloride. Processing is carried out 3-4 times during the growing season and at the beginning of flowering. Heavily affected areas are wiped with a solution of copper sulfate.

Traditional methods

Those who do not want to use chemicals in their garden can fight with folk methods. But activities must be started even before planting the seeds.

Procedure:

1. After the appearance of the fourth leaf, they are sprayed with a solution of brilliant green. Prepare it at the rate of 10-15 drops per bucket of water. They cultivate it from all sides, water the soil between the rows and near the plants.
2. At the first signs of the disease, the leaves are irrigated with a weak solution of slaked lime or wood ash diluted in water (a glass of ash in a bucket of water).
3. Use tinctures of garlic, celandine - half a bucket of herbs is poured with water, insisted for a day. Spray the plants in the evening.

Preventive measures

The most effective method of dealing with rust on cucumbers is prevention. You can pre-treat the plantation with preparations of the fungicidal group (Benomil, Chlorothalonin) or take other preventive measures:

• disinfect the seed material before planting with a solution of potassium permanganate for 30 minutes;
• treat the soil with Fitosporin before planting seeds;
• warm the soil with boiling water;
• fertilize the beds before planting seeds;
• observe crop rotation - do not plant cucumbers in the same place for several years in a row;
• regulate watering, prevent dry soil;
• mulch land between rows;
• remove weeds in a timely manner;
• water at the root, without touching the leaves.

Tips and tricks of experienced summer residents

Experienced gardeners know why rusty spots appear on cucumbers.

Petr, Kaluga: «I carry out prophylaxis before planting seeds in the ground. I soak the seed in a solution of potassium permanganate, water the beds with boiling water before planting. When the cucumbers rise, I fertilize with ammonia (1 tablespoon per bucket of water). In the future, I feed them every 2 weeks. I also spray it with a solution of brilliant green (10 drops per bucket of water). I never have red spots on the leaves of cucumbers. "

Masha, Orsk: “I always have a rich harvest. To avoid stains on the cucumbers, agricultural techniques must be followed. I water it 3 times a week so that the water does not get on the leaves. At the beginning of the season, I add ammonia, then a mixture of superphosphate, wood ash and potassium salt. I prepare the beds for planting in advance, add compost, rotted manure, peat. "

Read also:

A promising and high-yielding hybrid of "Kibriya" cucumbers.

Hybrid cucumber "Dirigent" from Dutch breeders.

Review of the Pasamonte cucumber variety.

conclusions

Often there is a problem in vegetable gardens - rusty and yellow spots on the leaves of cucumbers. The main reasons are fungal diseases and pests. Disinfection of the soil and seeds with a solution of potassium permanganate will prevent the disease, and watering at the root will prevent it from spreading. You can fight rust on the leaves with the help of chemicals or folk remedies.