Cucumber anthracnose: causes, symptoms and treatment with photos

Often, marble spots appear on the foliage, stems and fruits of cucumbers, destroying the cells of the plant. The disease that causes such a reaction is called cucumber anthracnose or verdigris. Consider the causes, symptoms and treatments for the disease.

Reasons

The disease is caused by the pathogenic fungus Colletotrichum. It enters through infected plant debris on the ground, often carried from one bush to another with the help of wind or rain. Also, seeds collected from diseased fruits become a source of infection. Crops that are both in the open area and in the greenhouse are susceptible to infection.

This is a dangerous infection, because it affects not only cucumbers, but also other vegetables in the garden - grapes, peas, melon, pumpkin, zucchini, beans and raspberry bushes, currants and gooseberries.

Greenhouses with a high moisture content provide comfortable conditions for the reproduction of the fungus. Fungal spore vectors.

wind;
prolonged wet weather;
insects;
instrument used on affected areas.

Conditions for the development of the disease

Wet and warm weather - comfortable conditions for the development of a fungal infection. It spreads with dew and frequent heavy rains. Fungal growth is activated when air humidity is above 60 degrees.

Greenhouses with high moisture content provide favorable conditions for the reproduction of fungus.

The incubation period of spore growth reaches 6-7 days, at elevated air temperatures it is halved.

Spreaders of spores from diseased bushes to he althy ones are aphids and spider mites, so these insects should be de alt with.

Planting density is also a reason for the transfer of spores from a diseased plant to a he althy one.

Under the right conditions, the fungus multiplies rapidly, causing disease to all plants growing in the garden. But when the air humidity drops sharply, the growth of the infection slows down and stops.

Symptomatics

Fungal disease in wet conditions affects the stalks of the sprouts, brown spots attack the necks of the roots. The fungus develops rapidly - the stem breaks, the seedling dies. On adult cucumbers, the fungus is able to infect all parts - root, stem, leaves and fruits.With the development of the disease on young shoots, they die.

Also, the reason for this phenomenon is non-compliance with the temperature and water regime. In adult cultures, the symptoms are as follows.

A few brown spots appear at the bottom of the bush.
The spots grow and merge, the leaf dries out, the stem turns black.
After the defeat of the leaves, the fungus passes to the fruits.
When the weather is dry, the infection site dries up.
When wet it starts to rot.

In the initial stage of development, leaves and stems are covered with copper-brown spots with a diameter of several millimeters to 4 centimeters. The spots are concentrated on the edges of the leaves and between the veins. First, one leaf located below is infected, and then the infection spreads to the entire plant. Therefore, it is difficult to recognize the disease in the initial stage of development.

The second stage leaves turn yellow, the diameter of the spots increases, and they merge with each other. As a result, the leaves lose their photosynthesis function, and the affected stems often break. Vegetable crops should be treated when the first symptoms of infection are detected.

The spots darken and dry out over time. On the stems, the foci are pressed inward by a few millimeters. The infection that has passed to the fruit also forms depressed areas, the young vegetable begins to rot.

When the humidity is high, the spots become covered with a fungal pink coating. These are spores that reproduce on the bush under wet conditions.

Infected fruit becomes bitter and unfit for food.

Cucumber treatment

In case of cucumber disease, treatment is started immediately.The following preparations are used to fight: solutions containing sulfur, Bordeaux mixture, Quadris preparation. These medicines kill the spores of the fungus, stopping the spread of the infection. They begin to use these funds at the first symptoms of the disease, with extensive distribution they are not very effective.

Fungicides used to treat anthracnose.

Topaz.
Fitosporin.
Previkur.
Abiga peak.
Quadris.
Polyram.
Cumulus.
Copper oxychloride.
Thiovit Jet.

Processing is carried out in protective clothing and a mask, after the procedure, hands are thoroughly washed in soapy water.

The root form of the disease is treated as follows: 1% Bordeaux mixture or 5% Abigo-Peak.Shed mainly under the root after abundant watering of plants with warm water. Only a small part of the mixture should fall on the cucumber stalks. Consumption - up to 1 liter per plant. The treatment can be repeated 2-3 times a week. This disease is rarely treated with folk remedies.

Prophylaxis plays an important role in preventing plant infection.

Prevention

Before planting, the purchased seeds are soaked in a solution of potassium permanganate. Soaking the seeds in Pseudomonas mycophaga, a culture fluid of bacteria isolated from the rhizosphere of cucurbits, also gave positive results.

Seed dressing is also carried out using the following chemicals.

Imvunnocytophyte.
Thiram.
Protravitel TMTD.

In addition to seed treatment, the soil is disinfected before planting. The applied fertilizers have a negative effect on the spread of the fungus. After planting, the seedlings are inspected daily for symptoms of the fungus. When an infected plant is found, it is removed.

When growing plants in film greenhouses, the accumulation of moisture on the film is monitored. With a large amount, shake it off, ventilate the greenhouse. Plants thinned and planted at a sufficient distance from each other will slow down the spread of bacteria. Removing old plants from the surface of the bed will also reduce the chance of infection.

Anthracnose appears not only on cucumbers, but also affects other vegetable crops grown on the site. This reduces the yield of plants by 50%. Therefore, it is important to carry out the prevention of all diseases, and if an ailment is detected, immediately begin its treatment.Under the right growing conditions, cucumbers will please their owners with a plentiful and he althy harvest.