Good day to all readers!
Today is an article about cucumber diseases and their treatment with photos and descriptions. To extend the term of fruiting cucumbers, it is necessary to know everything about their diseases, to be able to recognize them and take action in time. Photographs and a description of the diseases will help to identify them correctly and take measures for treating folk remedies. In order not to spoil the harvest chemistry.
Among the cucumbers that are grown in the open ground and the greenhouse, there are fungal, bacterial and viral infections. As a rule, plants are affected by these diseases due to improper care. Today we talk about
Causes of disease
- One of the most important causes of disease - failure to comply with the temperature regime. Due to temperature fluctuations, the disease develops faster. Favorable environment for infection - conditions of high humidity.
- It is possible that cucumbers will be sick in violation of the principles of crop rotation. Cucumbers are not returned to the previous landing site after 4 years.
- Among other causes of disease development - poor lighting, constant drafts, lack of supplements.
- In order for cucumbers to grow well and develop, it is necessary to identify diseased plants in a timely manner, to remove their affected parts.
- Also, do not forget about cleaning the site. On the beds should be clean and tidy.
- Often, cucumbers are sick because of improper irrigation with cold water.
Some diseases often affect plants in greenhouses, and others in open ground conditions. One of the most common fungal diseases of cucumbers -
If the plant is sick, a white or grayish bloom appears on its leaves and stems, similar to scattered flour. Over time, small powdery spots do not pass, but spread throughout the leaf. This leads to yellowing and drying of leaves, the cessation of fruiting.
Characteristic whitish plaque on the leaves
Powdery mildew pathogens spread very quickly at low air temperatures, when it is cloudy and cool outside. When the air temperature rises to + 25 ° С, powdery mildew spores die.
In most cases, cucumbers are ill, which lack moisture, weakened by irregular irrigation. Also, this disease appears if you overfeed them with nitrogen fertilizers.
To prevent the disease you need:
- pour warm water on cucumbers
- to maintain cleanliness in the greenhouse and on the beds - on time to weed, loosen, remove weeds and plant residues during growth and after the end of fruiting. Do not leave cucumber whips until spring in the beds.
- raise the temperature - close the greenhouse or cover the beds with film.
- Grow varieties resistant to powdery mildew.
How to treat folk remedies?
To get rid of the powdery mildew, the plant is sprayed mullein infusion. For its preparation, take 1 kg of mullein, pour it with 3 liters of water and insist 3 days. After this, the infusion is filtered and mixed with 3 liters of new, clean water.
Also suitable folk remedy, cooked based on sour milk, diluted with warm water (in a ratio of 1: 1). Sprayed cucumbers once a week.
Can be treated with soda solution. On a bucket of warm water 50 grams of baking soda and 50 grams of soap. Spraying repeated every 5-7 days.
It also helps spraying a solution of potassium permanganate - 2 grams per 10 liters of water. They moisten not only the diseased plant, but also the neighboring plants, and the ground around it.
Spray the drug Phytosporin at the first signs of leaf damage. You can spray and for prevention. This preparation is safe for people and plants - cucumbers can be collected on the day of processing. But, usually, in the morning they harvest and then splash on the leaves with a solution.
In case of severe damage, they are treated with fungicides or copper-containing preparations (for example, HOM).
You can also process the colloidal sulfur - 20% aqueous solution. The treatment is carried out in cloudy weather.
Perinosporosis - downy mildew
Downy mildew affects plants of any age, both in greenhouses and in the open field.
If peronosporosis is affected, cucumber leaves are covered with numerous light yellow spots. Over time, the leaves of the infected culture become brown and gradually dry out. If you do not treat the disease, then gradually all the leaves dry up, and behind them, and whip.
Common causes of illness:
The causative agent of the disease is a fungus. The favorable environment for its reproduction is the increased humidity, and can also provoke irrigation with cold water.
- Do not pour cold water
- Plant less cucumbers - do not thicken the planting
- To air the greenhouse
- Collect the fruits in time
- Treat seeds before planting
- Remove plant debris - spores can hibernate in them
- Plant disease-resistant and early ripe varieties
What to do with the disease?
At the first signs of the disease stop watering and fertilizing fertilizers.
This disease, unlike the phytophtoras on tomatoes, does not affect the fruit, so they can safely grow further.
An excellent prophylactic agent to combat powdery mildew is whey solution.
To displace pathogenic spores, spraying Fitosporin, the preparation of Baikal-EM, helps.
You can spray kefir with iodine (per liter 1 drop).
Or pollinate a bed of ashes.
All these tools are harmless to people - they can be used during the growth of the fruit.
Although I am not a supporter of chemical methods of struggle, I need to know about them.
Fungi do not like copper. Therefore, it is possible to treat the Bordeaux mixture (dissolved in a bucket of warm water, 100 grams of copper sulphate and lime) or with a copper-soap solution (20 g. Of copper sulphate and 200 g of soap per bucket of water).
It also helps the treatment of fungicides, which are many different in stores. Be sure to follow the instructions for use and maintain the time to harvest the fruit after spraying.
After treatment with a special tool, the temperature in the greenhouse should not fall below + 25 ° C. When growing cucumbers in open ground, they are covered with a film overnight.
Brown Olive Spot - Cladosporiosis
The first signs of brown spot are olive spots on the stems and fruits of cucumbers. Then brown ulcers appear on the fruit - the fruits lose their marketable appearance, and in case of a strong defeat they are not edible. This dangerous disease can deprive us of the harvest in a week, as the plants and cucumbers are quickly affected.
Cladosporiosis develops under adverse weather conditions - constant precipitation, with temperature drops.
When watering with cold water from above, on the leaves.
As a rule, the disease makes itself felt at the end of the growing season, when it becomes colder at night, a lot of dew falls out.
In most cases, cucumbers become infected with cladspiriosis due to fungus spores, which remain on the vegetable residues of vegetables.
To prevent the plant from becoming infected with this terrible disease, it is necessary:
- regularly air the greenhouse,
- for watering use warm water
- do not forget to remove plant residues from the beds,
- do not plant cucumbers in the shade
- water under the root
- in the greenhouse water in the morning
When the first signs of the disease are detected, the plant does not water for several days; it raises the average daily temperature in the greenhouse above + 18 ° C if it is cold. In hot weather - airing the greenhouse, remove the film from the garden (if covered).
Then treat with drugs containing copper (Chom, Bordeaux mixture, oxyf, etc.) or fungicides.
From biological products can be treated with phytosporin.
Plants should be treated only from a sprayer, not watered. Then dry the leaves - open the vents.
Why can cucumbers be sick? All pumpkin crops to which this vegetable belongs, suffer from the same diseases, from seedlings to the fruiting period. Prerequisites for the spread of pests and the development of diseases are the following factors:
- sharp and frequent temperature fluctuations in the greenhouse,
- lack of normal conditions for the growth and development of seedlings,
- increased air humidity
- drafts, insufficient lighting, lack of nutrients in the soil,
- frequent spraying of plants, excessive watering, irrigation with cold water,
- planting seedlings in the ground, where unsuitable predecessors of cucumbers (pumpkin, squash, zucchini, melon, watermelon) grew before,
- rare replacement of soil for landing.
Anthracnosis, or Coxa, is a disease that the Colletotrichum lagenarium fungus provokes. The fungus is very fruitful throughout the growing season. For such a disease characteristic yellowish brown round spots on leaves and cotyledons, and the affected areas of the leaves become brittle and begin to crumble. On the shoots formed in-depth spots, which are covered with pink-copper mucus.
If the infection has affected the fruit, then they appear indentations in the form of ulcers. At high humidity, such formations first become covered with pink mold, and then turn black. The cucumber tastes bitter, and during transport and during storage it rots. Such a vegetable is desirable not to eat.
If you find such a disease affected fruits need to be removed urgently, and the plant is treated with 0.4% chlorine oxide of copper. It is also recommended to use a one-percent solution of the Bordeaux mixture. The treatment is carried out once every ten days.
Perinosporosis and its treatment
Perinosporosis is a very dangerous cucumber disease that most often affects foliage. The causative agent of the disease in contact with the plant begins to develop very quickly, preventing the flow of nutrients. Mycelium may remain in vegetable seeds for many years.. The surface of the sheet is covered with yellowish-brown spots, which gradually begin to expand and coalesce. On the reverse side of the leaf there is a thick gray-purple bloom, the foliage shrivels, dries and falls.
Treatment of the disease lies in the fact that watering is suspended, and the soil is covered with wood ash. At night, seedlings should be well covered, and in the afternoon it is airing. Also, the plant can be sprayed with a solution of "Fitosporin", and the leaves on both sides are treated with copper-soap liquid or Bordeaux mixture.
Gray rot is a disease of cucumbers, in which there is an infection of the leaves, ovaries, flowers and fruits of cucumber with the mycelium of Botrytis cinerea. On the fruits appear slippery gray formations, which gradually begin to grow together.
The treatment is that the infected areas of the plant are removed, capturing at the same time a part of the healthy shoot. Cut points sprinkled with crushed coal, blue vitriol or lime. If the plant is not infected too much, it is recommended to use Bordeaux mixture. When rot appears on bushes, experts advise to spray them with fungicides:
This is a dangerous disease of cucumbers, which does not spare seedlings and adult plants. Very often the disease affects affected copies. The bacterium appears in the root zone., contributing to the drying out and the death of the entire root system. As a result, the lower foliage turns yellow, after which the bush dies completely.
With the defeat of cucumber seedlings disease, it begins to grow weakly and often dies. Root neck of infected seedlings covered with brown spotsthat quickly spread. After a while, the shoot becomes thinner, and the young leaves fade. Seedlings can be easily pulled out of the ground.
The treatment of the disease is carried out using the following biological preparations:
The colonies of this insect feed on the sap of the plants, leading to their exhaustion. Gourd aphid for a short time completely fills the bushes and destroys the crop. Leaves and stems shrivel first, then die. Often insects are observed on cucumber shoots and the back of leaves in July-August. The appearance of them in the greenhouse contribute to the weeds, which should be disposed of in time.
The most effective tool in the fight against melon melts is the use of tincture of tobacco dust and red pepper. To make it 200 g of tobacco dust and 30 g of pepper is poured over 10 liters hot water. The workpiece must be infused for 24 hours, then filtered and 3 tbsp added. l wood resin. One week after the initial treatment, the procedure is repeated. Also use chemical drugs "Inta-vir" or "Strela".
Whitefly greenhouse and spider mite
The whitefly is a pest that often infects plants in greenhouses. He can destroy the whole plant in a short time. The whitefly settles on cucumber leaves and sucks the juice from them, releasing a sugary substance. Pest accumulates in large quantities on the bottom of the sheet, leading to the fact that the shoots and leaves first blacken and then die. Against the insect use biological product "Aktophyt" (0.2%). The treatment is carried out 2-3 times during the growing season.
Cucumbers in the greenhouse often affects spider mites. Their number increases with increasing temperature. Such a pest can feed on both seedlings and adult plants. The presence of spider mites can be determined by the web, which is used to move ticks. Special preparations are used against the pest: "Akarin", "Talstar", "Bicol", "Fitoverm", "Clipper" and others.
Perinosporosis and Copperhead
The treatment of cucumbers for downy mildew with its minor manifestations is carried out using one percent solution of urea or milky iodide solution (a liter of skim milk is poured into 9 liters of water and 10 drops of iodine are added). A solution of copper oxychloride or Bordeaux liquid is good for this disease. In the most severe cases, the fungicides “Ridomil” or “Ordan” are used.
If cucumbers in open ground struck a creeper, all affected areas should be treated with copper sulphate (0.5%), and then sprinkled with lime or charcoal. Treat cucumbers every week Bordeaux liquid. Spraying stops a week before harvest.
Ascochitis and Fusarium
The treatment of this disease of plants in the open field is carried out using one-bordeaux fluidwhich process cucumber beds. Spraying procedure carried out once a week.
To combat fusarium wilt, only preventive measures can be used - before planting cucumber seedlings, the soil is treated with Fitoforin-M or Trichodermin biofungicides.
The plant in the open ground often affects aphids, which feeds on its juice. Ladybugs help to reduce its quantity. bring spring from field grass. Plants can be treated with infusion of wood ash or tobacco, adding laundry soap. Well relieve aphids infusions of garlic and onions. From biological preparations use:
Spider mites are fought by spraying. The solution can be purchased at the store. In the absence of such a possibility leaves are treated with soapy water. Cucumber beds can be populated by the natural enemy of the spider mite, phytoseiulus, which sucks eggs laid by females. But the settlement should be carried out every 2-3 weeks.
Minerals are pests that can infect cucumbers in the open field during fruiting. If there are a lot of insects, you can use the same biological preparations as against aphids.
Thus, there are quite a lot of diseases and pests of cucumbers, which should be eliminated as soon as possible. Thanks to proper plant care and timely prevention, the probability of cucumber contamination of pests and diseases can be practically reduced to zero.
Why cucumbers dry
Often gardeners complain that cucumber ovaries dry and fall off. This happens because the plants do not stepchild, and in fact everything that grows out of the sinuses of the first three to six leaves must be eliminated, while those stepsons that are formed above must be pinned above the 2nd leaf.
Another prerequisite for the fact that the ovary will turn yellow and dry may be the thickening of the planting - cucumbers have little food area, and they are unable to grow all their own ovaries.
You should know that cucumbers constantly form flowers with a margin in case negative conditions appear, and when all the buds are pollinated, the plant throws out excessive ovaries. So that reduction of part of the ovaries - This is a completely natural process that should not cause alarm in the gardener. However, what if cucumbers dry on a catastrophic scale for a vegetable garden and you are afraid for the next harvest? It is necessary to correct all the mistakes you made and hope that the plants will be able to re-enter the tone.
If already large fruits begin to wither, the reason may lie in the defeat of plants by the disease askohitoz.
Diseases of cucumbers in closed ground
Cucumbers are also dry due to the fact that the quality of fertilizer manure is applied during fruiting, но ведь именно на данной стадии становления огурцы имеют необходимость не в азотных, а в фосфорно-калийных удобрениях. Это значит, что навоз нужно исключить.
A prerequisite for the fact that the fruits of cucumbers turn yellow and dry can be growing bee pollinated species and hybrids instead of parthenocarpic ones in the greenhouse.
Why cucumbers turn yellow
Why do cucumbers turn yellow leaves? - This is probably one of the most frequently asked questions. True, in connection with which there is such a disease in cucumbers? And what action should be taken if the plant leaves turn yellow? Below we consider all possible causes.
If a the lower leaves turn yellow , this may mean that the plants have little light, but there is nothing terrible in it, so here you just need to cut off the yellowed leaves.
It happens that cucumbers turn yellow in the open ground because of the disturbance of water balance - or lack of, or excess water in the soil. One should not forget that cucumbers are a very moisture-loving crop, which in the usual summer asks for moisture two or three times in 7 days, and in extreme heat the plants need daily moisture. However, if the rains are charged for a long time, the excess water can become cause root rot and, as a result, we will soon discover again that the leaves have turned yellow.
However, the most common cause of yellowing due to fungal diseases - Fusarium, Pythiasis and others. As soon as the thirty-degree weather changes to cool rains and the temperature drops sharply at night, be prepared to fight fungi.
The leaves of cucumbers turn yellow and due to the defeat by parasites - whiteflies, spider mites or aphids.
And another reason for the yellowing of leaves may be a lack of nutrients in the soil: if the edges of the leaves dry and turn yellow, this means that the plant is experiencing magnesium or potassium deficiency, and dark green veins on a general yellowish background indicate a lack of manganese or iron. The lack of copper during cucumber disease also makes the leaves turn yellow, but only the upper ones ..
Well, the last prerequisite for yellowing leaves on cucumbers may be a natural process - old age. Over time, leaves coarsen, in them stops the process of photosynthesis and they, yellowing, die.
Why dry cucumber leaves
Reduction of leaves during cucumber disease can occur according to the same reasons as their yellowing - this is actually the next round of development of the problem. Including sometimes the leaves of cucumbers dry due to the fact that they were attacked by mites or aphids. Turn them over and look closely: if you find insects, process the cucumbers insectoacaricides: Aktellik, Aktar, or Bazudin.
The leaves dry out of peronosporoza, or downy mildew, and also from root rottenness caused by various fungi. How to treat these diseases of cucumbers, read below.
However, most often the leaves dry out for the most obvious reason - due to lack of water. Do not allow the soil to dry out either in the garden or in the greenhouse, keep the aquabalance at the proper level.
Why do cucumber leaves turn black
A dark patina on cucumber leaves may appear as a result of an attack on aphid plants: in the process of their vital activity, this pest leaves it to fall — wastes that are considered a suitable breeding ground for the black fungus that covers the leaves.
BUT dark mesh on yellowed leaves it appears as a result of cucumber disease by dark mold.
Why cucumbers fall
Therefore, why they dry: due to the fact that they are not stepson, because of a very large number of ovaries, because of a very dense planting and a small area of nutrition, due to incorrect feeding, and because of some fungal diseases. Read the rules for the care of cucumbers and correct your shortcomings.
Cucumbers wither leaves
On all the negative factors of the bushes of this plants react immediately it is the state of your leaves, and if you see that your cucumber leaves are fading, then look for the reason among the following options:
- insufficient, or excessive, or untimely watering,
- insufficient distance between the bushes in the garden,
- wrong plotwhich is too open to direct sunlight
- mistakes in carrying out dressing - the soil is oversaturated with fertilizers or, on the contrary, they are not enough,
- sudden cooling - cucumbers are extremely sensitive to temperature extremes,
- fusarium wiltwhite or root rot, perinospora,
- aphids or mites, or both.
All you have to do is discover the cause of the leaf wilting and eliminate it.
Cucumber leaves turn white
The emergence of this phenomenon may also be preceded by several circumstances. For example, the loss of color at the tips of the leaves (chlorosis) may occur due to lack of copper, plant-eating mites, aphids, and bacteriosis can occur on the leaves. However, most often these are symptoms of diseases such as powdery mildew and white mosaic. Unfortunately, if this culture can be cured of powdery mildew, then a white mosaic, alas, is incurable. The carriers of this viral infection are considered just sucking insects - mites and aphids.
How do cucumbers get sick and how can they be cured
We have already learned that black plaque can form on the leaves with a lesion of dark mold or black fungus. White bloom - the first sign of powdery mildew. Rose-copper plaque is evidence of plant damage by anthracnose. The white edge is a sign of white rot, and greyish green (bronze olive) appears in case of cucumber disease with kladosporosis, or brown spot.
Diseases of cucumbers in the greenhouse and their treatment
Diseases of cucumbers in the greenhouse appear as a result of damage by the same pathogens as in the open ground - fungi, viruses, microbes and bacteria. Only fungal diseases can be treated, and bacterial and viral diseases, Ufa, are virtually incurable.
Mealy dew on cucumbers
This is one of the most common diseases in the greenhouse, which can kill up to fifty percent of the crop. Disease begins with the onset of the formation of white bloom on the seamy side of the leaves, and on the face there are white powdery spots that grow evenly and darken. However, the matter is not limited to stains. The leaves are deformed and fall off, the fruits become small, start to taste bitter, and as a result the plant dies.
Control measures: as soon as the first signs appear, process cucumbers in a closed greenhouse at a temperature of plus 23-28 ºC fungicides:
in accordance with the annotation, after 10-14 days repeat the procedure. From folk remedies using mullein. From it make a solution in a five-liter vessel dissolve 1 l of mullein and 1 tbsp. urea spoon.
Cucumber Powdery Mildew (Perinospora)
it far unsafe disease, mainly affects the leaves: brownish-yellowish round or angular spots appear on their plane, expanding and coalescing, and their underside is covered with a viscous gray-violet bloom. With the development of the disease and the spread of spots, the leaves turn yellow and dry, turn brown, then shrivel, break and eventually leave the bush. In wet weather, the leaves die. Measures should be taken as soon as possible, because peronosporosis develops very quickly.
Fusarians, who grow cucumbers in greenhouses, most often face fusarium wilt. First, the tops of the plant and the individual leaves wilt, then the root collar rot.
The trigger for the development of the disease is the increased humidity. The causative agent of Fusarium wilt is transmitted through seeds and soil. But it usually manifests itself after the start of fruiting - the bush begins to gradually fade and quickly ends up bearing fruit and fades completely.
Under the condition of increased temperature and lack of watering, the disease develops rapidly - in a few days all infected bushes can wither.
The prevention in processing of seeds before crops, and cleaning of the vegetable remains. To displace pathogenic fungi from the soil, it is shed with a solution of Fitosporin or Trichodermine, a week before planting seedlings or seeds. Also, the introduction of high-quality compost helps the earth to improve its health.
This pathogen is very resistant to chemicals and its spread is better not to allow. With good care, timely watering healthy plants do not get sick, even in the presence of pathogens in the soil.
With white rot disease, multiple white bodies appear on cucumbers. Over time, they become darker in color. After that, all parts of the plant are completely covered with white mucous coating.
Sclerotia fungi multiply rapidly when the air is too humid and the soil is wet.
As a preventive measure, they avoid thickening of cucumber crops, observe crop rotation and remove plant residues from the beds in time.
The damaged parts of the plant are removed, sections are treated with lime, charcoal or a mixture of copper sulfate and chalk in half.
You can spray the plants with a serum solution (3 liters of serum, 7 liters of water and a teaspoon of copper sulfate).
Of the chemicals used Oxyhom, Home, Topaz (according to the instructions). Spraying is carried out after harvesting.
After the last harvest of the fruit, the bed is treated with a solution (50 g of copper sulphate on a bucket of water). Then leave for a day, then collect all plant residues, whip cucumbers with roots and burn outside the site.
The carrier of an ordinary mosaic is aphid. When the disease leaves the cucumbers are yellow-green in the form of a mosaic. Then they curl, dry up and fall off. The plant becomes very weak and stops growing at the first low temperatures and dies off.
Mosaic virus overwinter in weedy grass (in the roots of quinoa, woodlice, wheatgrass, bindweed) - therefore it is difficult to fight it. With seeds, this disease is not transmitted.
For prophylaxis, plants are sprayed with a 50% serum solution (diluted 1: 1 with water), and at the onset of the disease with an undiluted solution.
You can spray a solution of phytosporine (according to the instructions). For the prevention of disease sprayed not only plants, but the earth around.
To prevent disease, weeds are removed.
White and green speckled mosaic
Among the signs of a white mosaic, individual white or yellowish spots first appear, and then they merge into a common spot and the leaf becomes white with green veins. The growth of lashes slows, female flowers on such plants is small. It is also transmitted to the fruits - small depressions appear on them, the flesh becomes dense, the rind turns yellow.
With a green speckled mosaic - the leaves become wrinkled with light spots. Plants are also stunted and fruits become deformed with a mosaic color.
Unlike ordinary mosaic, the virus is transmitted through infected seeds, it can also remain in the ground and plant debris.
Usually provokes the disease a sharp rise in temperature from + 20 ° C to 30 ° C and above. It develops rapidly in greenhouses, hotbeds, closed beds, especially with sudden temperature changes and thick plantings.
To avoid infection, before planting the seeds are pickled and heated. The best way to avoid illness is to take good care.
In order to prevent:
- sprayed with a weak serum solution,
- remove immediately damaged leaves and shoots
- plant the plants at the optimum distance,
- remove weeds,
- fight with aphids - the main carrier of the disease,
- warm water
- remove diseased plants and burn
Why do the leaves turn yellow?
Many gardeners are faced with premature yellowing of the leaves. If there are no diseases, and the leaves start to turn yellow early, then the reason lies in the lack of potassium, magnesium or sudden changes in temperature.
Smoothing the temperature mode can be, if at night to cover the plants film.
If you do not have enough potassium, cucumbers sprayed with infusion of ash.
Onion infusion is quite effective. It is prepared in a metal bucket. 50 grams of onion peel is added to 10 liters of warm water. The content should boil, and after that the infusion is cooled, filtered. Cucumbers with yellow leaves are watered with a slightly warm extract.
Yellow cucumbers with improper watering:
- Water often, but not enough. In this case, only the top layer of soil is moistened, and the lashes and leaves lack nutrition.
- Watering is rare, but abundant. From the excess moisture roots can rot, the leaves will begin to wither and turn yellow. Or in light sandy soils, the water will quickly go away and the plants will lack moisture.
It is necessary to ensure regular watering of cucumbers, loosen and mulch the soil after watering.
Cucumber disease is easier to prevent than to seek treatment. If it is necessary, then try to defeat the disease by popular methods, so as not to poison the crop.
Chemicals are used in extreme cases.
I wish you healthy and beautiful cucumber beds!
The main diseases of cucumbers with photos and descriptions
The sudden illness of a cucumber can deprive the summer resident of the entire crop. Therefore, cultures are not only struggling with diseases when they have already appeared, but also carry out mandatory prophylaxis that contributes to their prevention. Cucumbers are subject to the following diseases:
- Bacterial and viral.
Anthracnose or verdigris
This is perhaps one of the most dangerous diseases. Gherkins, grown in greenhouses or under film material, are particularly susceptible to this disease. Both leaves and fruits are affected. The appearance of the lesion looks like yellow or brown spots of a round shape on the leaves of cucumber plants.
As for the fruits, they can be found dents, large enough size, which eventually become covered with moss pinkish reflux. All this leads to drying out or rotting of the fetus. The first signs of the disease of greenhouse plants can be found already on the shoots.
The cucumber may fall ill with the cure in the following cases:
- Seeds of cucumbers for seedlings already have the causative agent of the disease. This is because the seeds were taken from an infected culture.
- Contact with the cucumber tops, not harvested from last season, on which disputes can spend the winter, with the new season activated.
- Increased rainfall during hot weather. This is due to the humidity of the air, because in a dry climate, anthracosis is almost impossible.
In another way, this disease is called olive blotch, since that is how it looks in reality. On the fruits themselves, small water spots first appear, turning into ulcers of olive color. These sores then begin to fall through. If the humidity is high, then the spots begin to become covered with brown bloom. Also, the manifestations of this infection can be seen on the stalks of cucumber - they are exactly the same spots of olive color. As for the leaves, they begin to dry out, leaving only the veins.
Naturally, the fruits that the disease found at an early stage of development remain underdeveloped and twisted.
The percentage of development of cladosporia increases dramatically with increased precipitation, high humidity, etc. It is the water that carries pathogens throughout the crop - this can happen even during the irrigation process. But in the drier and hot summer splashes of this disease is not observed.
Bacterial and viral diseases of cucumbers: causes, treatment, prevention
Viral and bacterial diseases of cucumbers occur with the direct contact of a healthy culture with the patient or are carried by seeds. Such contact is observed at harvest, when pruning plants, etc. Most likely, such a disease can be picked up by a cucumber from weeds that breed in clouds around it - for example, a sow thistle or bindweed. The most significant diseases of this origin are:
English cucumber (or green speckled) mosaic
Especially dangerous for cucumber in greenhouse conditions, also the likelihood of its occurrence increases many times in the hot summer, when the thermometer tends to mark 30. The disease most often appears about a month after the cucumber transplanting to the greenhouse. The virus is in last year’s plant residues, in the seeds themselves, in the soil on which the crop is planted.
The signs of cucumber disease in English cucumber mosaic are the appearance of yellow stars on the leaf. Then they cover the whole leaf, after which it shrinks, dries out. As for the fruits themselves, they acquire white stripes that tighten its tissues. Slowed crop growth is also a sign of green speckled mosaic. Treatment of viral diseases is not yet produced, the diseased plants must be carefully removed from the soil and burned.
This viral disease can affect not only greenhouse, but also street cucumber. The external signs of the manifestation of the disease are in many ways similar to the English mosaic - the same slow growth that will be noticeable at an early stage, light green areas on the plant tissue, thinning of the stem at the very base, death of the tissues.
It is noteworthy that the mosaic virus is not commonly found in cucumber seeds - it can be transmitted only from weed (common sow thistle), flowers (gladiolus, dahlia, phlox) or from sucking insects (for example, aphids).
Когда-то считалось, что для снижения вероятности заболевания ни в коем случае нельзя допускать распространения сорняков около культуры ближе, чем на 10 м, такое же расстояние рекомендовалось выдерживать между посадками огурца и цветочными клумбами. Но в природном земледелии и к сорнякам и к уплотненным посадкам относятся по-другому – разнотравье улучшает экологическую среду на участке. Поэтому, при выявлении пораженных растений просто аккуратно извлеките их из грунта и сожгите.
The causative agents of the disease, wintering on organic debris, are especially rapidly spreading in overcast and cool weather. If the average daily temperature rises above +18. + 20 ° C, powdery mildew stops its development.
The disease most often affects plants that are “overfed” with nitrogen fertilizers, as well as those that are irrigated irregularly and insufficiently.
As soon as you notice the first signs of powdery mildew, immediately spray plants with fungicides, such as topsin. Or treat them with a solution of the preparation "TOPAZ", for the preparation of which mix 2 ml of the preparation with 10 liters of warm water. Spraying is carried out in windless dry weather for the prevention of the disease, and at the first signs of its occurrence.
Good results in the fight against powdery mildew gives the treatment of plants with a preparation "HOM" (copper oxychloride solution). To prepare the solution, take 40 g of powder and dilute it in 10 liters of water. Spray the plants, consuming 1 l of the resulting solution per 10 m².
Can process plants colloidal sulfurusing a 20% solution in open ground (for 10 liters of water 20 g of colloidal sulfur) and a 40% solution for protected ground (for 10 liters of water 40 g of colloidal sulfur). The resulting solution to process the leaves of the plant in cloudy weather on both sides.
If you consider the use of chemicals at your dacha to be unacceptable, try to cope with the disease using powdery mildew.
- Spray the plants with a mullein infusion: mix 1 kg of raw material with 3 liters of water, leave for 3 days, strain the infusion, mix it with 3 liters of clean water and spray the plants.
- Mix 1 l of sour milk with 1 l of warm water. Strain the solution and spray plants once a week.
- Dissolve 50 g of baking soda and 50 g of soap in 10 liters of warm water. Spray this solution on cucumbers every 5-7 days.
Downy Mildew - Perinospora
On the leaves of cucumbers appeared small, but numerous light yellow spots? Last week - the spots increased in size, and the leaves themselves turned brown and began to dry out? This means that cucumbers are infected with powdery mildew, or peronosporosis, a very dangerous and common disease that can affect plants at any stage of their development.
Downy mildew - Peronosporaz.Photo from greentalk.ru
Sclerotinia - White Rot
At first, multiple white bodies appear on all affected areas of the plant, which eventually become dark, even black? Then the leaves, the stems and even the fruits of the plant are covered with a continuous white bloom, become lick, soften and rot? This is sclerotinia, which is often called white rot.
Sclerotinia - white rot. Photo from fr.academic.ru
Numerous brown spots appeared on the leaves, stalks and even fruits? The affected leaves began to dry out gradually, and the fruits were covered with wet ulcers? Recognizing the disease is not so difficult - the plants are infected with anthracnose or, as it is often called, cooper.
Anthracnose (verdigris). Photos from the site 693437.ucoz.ru
Why do cucumber leaves turn yellow?
Most likely, the reason is the temperature drop during the day and at night and (or) the lack of potassium. And if in order to raise the night temperature, it is enough just to cover the cucumbers for the night with any covering material — film, spunbond, etc. — then, in order to cope with the second problem, it is necessary to apply a little more effort.
Cucumber leaves turn yellow prematurely. Photos from sazenec.ru
Spray the plants infusion of ash. To prepare such an infusion, dissolve 3 tablespoons of ash in 1 liter of warm water and let it brew for 2 days.
It will be useful to feed cucumbers onion infusion. To prepare it, take a metal bucket, pour 10 liters of warm water into it and, adding 50 g (about 2 tablespoons) of onion peel, boil the contents. Let it stand. When the onion infusion becomes barely warm, water the plants with them, consuming 1 liter of infusion per 1 bush.
Also, when growing cucumbers, you may face another problem: their stems crack. Why this happens and how to cope with the problem, you will learn after reading the discussion of the post Why is the stem cracking cucumbers and zucchini?
And how do you fight the most common diseases of cucumbers? Tell us what secrets and tricks are known to you, and how do you succeed in this difficult task?
Downy mildew or perinospora
Disease on the leaves of cucumbers.
The causative agent is a peronospore mushroom. Downy mildew differs from the present in that the mycelium (mycelium) develops from the lower side of the leaf, and spots appear on top. The spots themselves, unlike pepelitsa, yellow or brown.
The disease often affects greenhouse cucumbers. Its spread is promoted by high humidity and cold nights. Appears more often in late July and early August, but may occur earlier. Saved in the soil for 6-7 years.
Signs of defeat. The disease manifests itself on the leaves of cucumbers. On the upper side of the leaves appear numerous yellow-oily spots of irregular shape. Within 5-7 days, the spots increase and turn brown. From the bottom side, the mycelium is a white-purple bloom.
The leaves dry out within 2-3 days. A disease in a week can destroy the whole greenhouse.
Ways to treat the disease.
- Stop watering and well-ventilate the greenhouse.
- Remove all affected leaves.
- Sprinkle ashes under the plants to prevent the spread of the pathogen.
- Treatment with drugs Previkur, Consento, Revus.
- The use of preparations containing copper: Abiga Peak, Ordan. Bordeaux mixture in the fight against peronosporaz ineffective.
- Spraying with biological products: Trichoderma, Gamar.
- Spraying a bright pink solution of potassium permanganate.
- 25 g of soda ash is dissolved in 5 liters of hot water, 5 g of tar soap is added. Sprayed cucumbers in the initial stage of the disease.
All spraying carried out on the underside of the leaves.
If cucumbers are planted in one greenhouse from year to year, then the spores of the fungus accumulate there in large quantities.
- Early spring removes topsoil, replacing it with fresh earth.
- Preventive spraying of cucumbers with biological products Fitosporin and Gamar. The interval between treatments 5-7 days.
- Growing resistant to peronosporoza varieties: Affin, Darling, Octopus, Pecti, Crew.
Prevention is quite an effective method. It reduces the risk of peronosporosis 1.5-2 times.
Bacteriosis or angular spotting
The causative agent is a bacterium from the genus pseudomonas. It is stored on plant residues and in seeds. The development of the disease contributes to high humidity and temperature. Most often affects greenhouse cucumbers. Indoors should not be watered by rain, as drops of water on the leaves contribute to the spread of infection.
The disease affects leaves, fruits and seeds. The disease can occur during the entire growing season, including in the seedling phase.
The disease appears on the leaves, and then goes to the green.
- Yellow, angular spots appear on the leaves, which then become gray-brown and dry. In this place the fabric falls out, holes appear on the leaves, and then they dry out. Dull pink droplets appear on the underside.
- On the fruits appear brown sores, which are filled with dirty-pink contents. When the fluid dries, a film appears on the surface. In places of the appearance of spots the fruits are bent. The infection penetrates into the pulp of the fruit, and from there into the seeds, where it remains until the next season. Zelentsy with angular spotting become inedible. But the disease at dachas, as a rule, does not reach this stage of development.
If you do not take urgent measures, the plants die.
How to treat bacteriosis. Despite the fact that the pathogen of bacterial origin is treated with fungicides (antifungal agents). They are quite effective.
- Copper preparations are most effective against bacteriosis: Kuproksat, Bordeaux mixture, Abig Pik. Zelentsy then can not be eaten for 20 days.
- Use of biological product Fitolavin. It belongs to phytoantibiotics (biobactericide) and completely destroys the causative agent of the disease. To prepare a working solution, dilute 2 ml of the drug in 1 liter of water, the consumption rate is 10 l / 100 m 2. The solution is used only fresh, it is not stored.
- In a top dressing, increase the dose of potash fertilizers or make additional potash fertilizer.
There is no effective folk remedy against bacteriosis.
- When the first signs appear, watering is reduced, and greenhouses are constantly airing. Humidity should be reduced to 80-85%. Air, soil and plants must be dried.
- Collection and destruction of plant residues.
If bacteriosis appeared in the greenhouse, it is advisable to replace the earth in the fall.
The disease usually accompanies bacteriosis. It affects all aboveground parts of the plant: leaves, lash, green. Manifested in the second half of summer, greenhouse cucumbers are particularly affected by anthracnose.
The causative agent is a fungus that remains on plant residues.
Signs of illness. Initially, the disease infects the leaves. Vague, brownish spots appear on them, which then merge. Most of the sheet takes on the baked appearance. The leaves dry and crumble. On the lashes and stalks may appear mucous pads of orange color.
Cucumber leaves sick anthracnose.
Later anthracnose infects young greens. Brown sores appear on them with hard edges. They are very similar to poklev birds. Affected cucumbers are unfit for food.
Disease treatment. The fungus is particularly hard on cucumbers in hot and humid summers. In the greenhouse culture is sick more often than in the open field.
- At the first signs of illness, the affected parts of cucumbers are removed and burned.
- At an early stage of development, biopreparations are quite effective: Alirin B, Fitosporin.
- Spraying cucumbers with copper preparations. It is advisable to make a preventive spraying after the appearance of 5-6 sheets. Then the probability of the defeat of cucumbers by anthracnose is markedly reduced. Copper has a good healing effect, but after processing, green stuff cannot be eaten for 20 days. Simultaneously with spraying, watering with the same preparations is carried out, since the pathogen is preserved on the soil and the lower yellowed and fallen leaves.
- Disinfection of greenhouses in the fall. In the greenhouse, the sulfur bomb is set on fire, and 3-5 days after that, the earth is shed with copper sulphate (1 tbsp per 10 l of water) or with a dark raspberry solution of potassium permanganate. You can sprinkle the earth with bleach, and a week later digging shovels with a bayonet. But this should be done only in the fall.
- In the spring, you can also set fire to a sulfur checker. The earth is spilled boiling water several times.
- During the growing season, 2-3 prophylactic spraying with copper preparations should be carried out.
- Destroy the weeds around the cucumber plot, as they can also be affected by anthracnose.
- The greenhouse is constantly aired. It is especially necessary to do this in the early morning when dew appears on the leaves of cucumbers.
Anthracnose is easier to warn than powdery mildew or downy mildew.
Brown (olive) spot or cladosporia
Disease of fungal nature. Occurs more often in greenhouses. The main cause of the disease is sprinkling of cucumbers with cold water, as well as cold weather (10-13 ° C during the day and at night). The pathogen is stored on plant debris and in the soil, it is well tolerated by adverse winter conditions. Therefore, when growing cucumbers in greenhouses, when the disease appears, it is necessary to change the soil and disinfect the greenhouse.
Signs of the disease. More often it affects young greens, less often leaves. Brown and dark brown sores appear on the leaves, emitting drops of turbid liquid. Gradually the spots cover the whole fruit, and it becomes inedible.
Small dark brown spots appear on the leaves, which gradually merge.
How to treat:
- Copper treatment.
- Airing greenhouses.
- At the very beginning of the development of the disease, Biopreparation treatment is Fitosporin, Pseudobacterin, Gamar.
- Do not water cucumber sprinkler.
- Watering only with warm water.
- Timely cleaning of all affected fruits and leaves.
- It is desirable to produce a crop rotation in the greenhouse.
- Growing resistant varieties: Cupid, Alphabet, Amazon, Valaam, Dobrynya, Green Wave, Cellar, Five Stars.
Cladosporiosis is very harmful. If you do not take measures, you can be left without a crop.
Cucumber Mosaic Virus
This is how sick leaves look at cucumber mosaic.
Pathogens are a group of viruses that cause various manifestations of the disease. In addition to cucumbers, viruses infect tomatoes, sweet and hot peppers, lettuce, beans, cabbage, currants, raspberries, and about 700 cultivated and wild plants. The virus persists on plant debris and in the roots of weeds for several decades. Viral diseases mainly affect greenhouse cucumbers. In the open field the disease on the culture almost does not occur. The disease is very dangerous, if no action is taken, it can appear on most garden crops, as well as on shrubs.
On the summer cottages there are 2 types of pathogens: the green speckled virus and the mosaic virus.
Green Mottled Mosaic of Cucumber
Crop losses up to 50%. The virus affects crops growing with cucumbers in the same greenhouse (except for eggplants). Cucumbers are affected during the entire growing season, starting with the seedlings.
The virus spreads with seeds. Also, from diseased plants to healthy ones is transmitted by contact when caring for cucumbers.
Description of the disease. The disease may not manifest for a long time. The first signs occur after a sharp rise in temperature above 30 ° C. Veins on the leaves become yellowish. Along them appear pale yellow strokes or spots, which then spread to the entire sheet. Dark green and yellow-silvery spots appear. The leaves are deformed and die.
On greenhouses appear the same spots and strokes. Some strains of the virus cause deformation of the fruit. Cucumbers become shortened and bitter, in varieties the seeds do not develop, but remain in their infancy.
Ordinary mosaic of cucumber
The source of infection is infected seeds. The virus is actively carried by aphids. In winter, it is preserved on weed plants (woodlouse, sow thistle, quinoa), as well as on infected currant bushes, raspberries.
Signs of defeat. The earliest signs may appear even during the period of emergence, but usually the first symptoms appear during the growth of the lashes. Yellow and dark green spots appear on diseased leaves, the leaf becomes lumpy, corrugated, shrinks, its edges bend down. Around the veins, the color may become dark green.
The leaf struck with an ordinary mosaic.
Cereals become speckled or striped, shrinking with a strong lesion. Dark green areas become convex, and places with normal or light coloring are depressed. Fruits are especially deformed when the temperature drops to 17-19 ° C.
On the lashes internodes are shortened. The growth of lashes is suspended. If the first signs appear in the second half of the summer, the cucumbers are not damaged so much.
- When the first signs of infection of cucumbers (and other cultivated plants and shrubs) appear, they are treated with Farmod, which has a strong antiviral effect. The drug is sold in garden stores. You can use its analogue Povidone iodine. After processing, do not water the cucumbers on the leaves and prevent the formation of condensate in the greenhouse, because the preparation is easily washed off the treated surface.
- With severe infection, diseased cucumbers are removed and burned, the rest are treated with Pharmamod.
Prevention of the disease.
- Cutting all weeds around the perimeter of the plot.
- It is not recommended to plant other pumpkin crops alongside, as the virus is transmitted with water, soil, and when plants come into contact with each other.
- Destruction of aphids at the dacha.
- Growing virus-resistant varieties: Alphabet, Mischief, Nezhinsky, Funny friends.
- Complete replacement of land in the greenhouse.
The cucumber mosaic virus is very dangerous. If after the first treatment the symptoms of the disease continue to grow, then the plant is removed. Sometimes you have to completely destroy all greenhouse cucumbers, then you have to choose between the preservation of plants and a very high risk of infection of shrubs and trees.
You might be interested in: