Why flowers are sick - symptoms and treatment of plant leaf diseases


Houseplants Published: 06 August 2012 Reprinted: Last edits:

Caring for plants can bring both joy from the sight of beautiful and healthy flowers, and upset from failures: if a plant sheds foliage, does not bloom, withers and dies before our eyes, inexperienced growers begin to panic, not knowing how to save their favorite flower. However, there are no hopeless situations, you just need to know where to look for a solution to the problem. In this article, we will tell you about the symptoms of the most common plant ailments, as well as the causes of their occurrence.

Plant disease symptoms

The plants you just bought are dropping leaves.

Plants, like humans, can experience stress as a result of changes in habitual conditions, and the first sign of such stress is the loss of leaves by the plant. To minimize the discomfort from moving, the plant must be wrapped during transportation in the winter season - protected from cold air.

Leaves fall off instantly without losing color and turgor.

Most often, such consequences are caused by a sharp change in air temperature or cold drafts. Another reason may be a significant and sharp increase in the amount of light - you need to increase the light intensity gradually.

Treelike plants can shed their foliage abruptly if you allowed the earthen coma to dry out too much.

The leaves turn yellow, then crumble.

Many plants gradually begin to shed the lower leaves over time - this is a normal biological process that does not require action. If the plant sheds several leaves at once, then most likely this is caused by cold drafts or excessive moisture in the soil for a long time.

The leaves roll up and fall off.

Often this symptom indicates that the room is not warm enough or that the plant has been in cold drafts, or that the soil in the pot does not have time to dry out between waterings.

The lower leaves dry and crumble.

This could be a sign that the plant is lacking water. Another reason for the phenomenon may be too high air temperature and lack of lighting.

The upper leaves turn yellow.

If the leaves turn yellow, but do not wither, then this is usually due to the fact that too hard water is used for watering the plants (the water must settle for at least a day before watering). Another reason may be an excess of potassium in the soil, despite the fact that the plant does not tolerate lime.

The stems and leaves of the plant rot.

This is usually caused by water spilling on leaves or in a leaf outlet in a cold room environment. In winter, the frequency of watering and spraying for almost all plants should be reduced.

Brown spots appear on the leaves.

Dry spots are usually the result of insufficient watering. Keep in mind that almost all plants need to be watered as soon as the topsoil dries.

If the stains are soft and damp, then this means that you overdid it with moisture.

Yellow or white spots on the leaves.

Such spots can appear if the plant is in direct sunlight for a long time (many plants cannot stand the bright sun). Another reason: the plant is sick or infested with pests. Spots also appear if the plant is watered with cold water or the water gets on the leaves during watering.

The edges and / or tips of the leaves dry and turn brown.

This happens most often if leaves are constantly touching a wall, window, or some other object. These changes are often caused by too dry air. Try to increase the humidity by spraying the plant or the air around it with water at room temperature.

Brown or yellow leaf edges.

This ailment is the result of a number of reasons. The edges of the leaves turn yellow or acquire brown color both from the lack of moisture in the soil, and from its excess; due to dry indoor air; when overfeeding plants with mineral fertilizers; due to cold drafts. Such changes occur when the temperature regime is violated - too high or too low temperature than the plant needs. Another reason may be excessively strong or, conversely, insufficient lighting.

The leaves are drooping.

This is a symptom of a violation of the irrigation regime - both an excess of moisture in the roots and a regular lack of it. Leaves may wilt if the indoor temperature is higher than the plant needs and the lighting is too intense. Or if the pot is small and the flower needs to be transplanted into a larger container. Other reasons: damage to the plant by pests or insufficiently high humidity in the room.

The leaves turn pale.

The plant can be infested with spider mites or suffer from too bright light.

Holes and torn edges on the leaves.

This is either pest damage or mechanical damage.

Leaves are discolored.

Lack of light can lead to the fact that plants with variegated leaves lose their pattern and become monochromatic.

The stems are elongated, and the new leaves grow small and pale.

The plant lacks minerals, and it needs feeding, or it lacks light. The plant also stretches out with improper wintering - too high room temperature, unjustifiably abundant watering with insufficient lighting.

The plant does not grow or grows slowly.

For the winter period, this is normal, since most indoor plants have a dormant period in winter. If the plant is in a period of active growth, but does not develop, then the reason may be a lack of minerals. Development may stall due to the fact that the roots have filled the entire pot, and the need for a flower transplant is ripe. Excess moisture in the soil and lack of lighting can also inhibit plant growth.

The buds are falling.

Falling buds are often caused by the same causes as falling leaves. In addition, the buds crumble due to insufficient moisture in the soil and air, from a sharp change in lighting, when damaged by pests or from a change in the place of a flowerpot with a flower at the time of budding.

Lack of flowering.

One of the main reasons that the plant does not bloom is improper care during the dormant period. The plant does not bloom if the air humidity is too low, if it does not have enough light, or if too many minerals have accumulated in the soil. Some types of plants do not want to bloom in a spacious pot.

Short flowering.

Flowers can quickly fade from lack of water - from too rare or sparing watering, from insufficiently high humidity, which can be increased by placing the pot on a pallet with wet expanded clay, from heat or lack of light.

Plaque on a ceramic pot.

Green bloom indicates excessive watering or poor drainage - the soil does not have time to dry out or excess water does not leave the pot.

White bloom appears when watering the soil with hard water (we remind you: the water must be defended for a day before watering) or when over-feeding with mineral fertilizers.

All these troubles can be fought, but it is easier to avoid mistakes in care, strictly following the rules for growing indoor plants. After all, it is easier to prevent a problem from occurring than to look for ways to fix it later.

Literature

  1. Plant Disease Information

Sections: Diseases Diseases of indoor plants


Why flowers are sick - symptoms and treatment of plant leaf diseases - garden and vegetable garden

We all know our green pets get sick. And as soon as we see signs of change, we rush to help them, but often our attempts do not lead to anything, or it only turns out worse.
But the fact is that in addition to diseases and pests, there is simply a lack of nutrition. Plants show us that we need help, but it is difficult for us to understand them - the language of plants is not understood by many. Now I decided to make a small selection with color photos for roses. We have already done visual diagnostics for vegetables, as well as for ornamental plants, so use labels more actively.

Leaves lose their green color, young leaves are pale green, red dots appear on them, the leaves become narrow and fall off prematurely. It manifests itself primarily on old leaves. Shoots are shortened, flowering weakens. The wood of the stems does not ripen well, winter hardiness decreases. Top dressing with nitrogen fertilizers, preferably foliar.

The leaves are dark green with a red or purple tint. Purple-brown stripes and spots (especially below) may appear on the edges of the leaves, the leaves become smaller, become narrow, move away from the shoots at an acute angle, fall off, the growth of shoots is delayed, they are bent. The stems, petioles and veins of the leaf acquire a lilac color. Shoots are weak, often blind. Flowering is delayed, the root system is poorly developed. Plants lose their decorative effect. If there is a deficiency of phosphorus, the plants must be fed with superphosphate or complex fertilizer (1 tablespoon per 10 liters of water), the soil must be mulched with peat, followed by embedding it in the ground.

With a deficiency of potassium, the edges of the leaves turn yellow, the veins remain green. Often the edges of the leaves dry out. Gradually, the leaves turn yellow completely and acquire a reddish-purple color. Yellowing begins at the top of the leaves. The flowers are small. Young leaves turn reddish with brown edges. Often seen in roses growing on sandy soils. The withering process starts from the lower leaves and spreads to young leaves. They turn black, and the stems of roses die off. Usually, roses lack potassium on sandy and peaty soils. With a lack of potassium, roses must be fed with potassium fertilizers - potassium sulfate, potassium magnesium or complex fertilizer (1 tablespoon per 10 liters of water).

LACK OF MAGNESIUM
Symptoms Treatment
On old leaves, and then on young ones, discolored spots appear in the middle of summer. Dead dark red areas are formed between the veins, dying off zones of reddish-yellow color. The edges of the leaves remain green. Leaves fall prematurely. Magnesium deficiency is eliminated by the introduction of fertilizers containing magnesium - magnesium sulfate, ash. Often occurs in roses growing in acidic soils. Feed with complex fertilizer, add ash.

Symptoms Treatment
Plants experience iron deficiency very often on neutral, alkaline and calcium-rich soils. Leaves turn yellow starting from the edges. Young leaves are especially affected. A narrow green strip remains around the veins. If chlorosis progresses, small veins also become discolored. The leaf becomes almost white or cream-white in color, then the leaf tissues die off and they fall off. If there is a lack of iron, it is necessary to add rapidly decomposing organic fertilizers or any acidifying fertilizer to the soil, two-three times to carry out top dressing with iron-containing preparations (complex fertilizer "Kemira Universal 2" - 1 tablespoon per 10 liters of water).

Symptoms Treatment
It occurs with an excess of potassium. Calcium occurs naturally in the form of limestone, chalk and other compounds. It is necessary for plants for the normal development of the aerial part and the growth of roots. With a lack of calcium, the stems and leaves are weakened, the tops of young leaves are sick or die off, the peduncles die off, the roots do not develop. Young leaves are crocheted. Plants need to be fed with superphosphate or calcium nitrate (1 tablespoon per 10 liters of water).

LACK OF MANGANESE
Symptoms Treatment

In affected plants, leaves turn yellow between veins from edge to center, forming tongue-shaped patches. A green rim is formed around the veins of the leaf. A yellow color appears on older leaves (on this basis, it is easy to distinguish from chlorosis due to a lack of iron: with a lack of iron, young leaves suffer, with a lack of manganese, old ones). In this case, the plants need to be fed or sprayed with a solution of manganese sulfate and the lime content in the soil should be reduced, that is, physiologically acidic fertilizers should be added to the soil - peat, leaf or coniferous litter, potassium sulfate or ammonium sulfate, etc.

LOCKING OF THE ROOT SYSTEM
Symptoms Treatment

Locking the root system leads to its death. At the same time, yellow spots appear on the leaves, in the middle of the leaf plates, which increase and turn brown over time. Leaves fall off, bushes often die completely. First of all, of course, try to normalize the condition of the soil so that stagnant water does not form in the flower bed. In severe cases, the rose may have to be dug up, cut off decayed roots and shoots, and transplanted into a pit or to a new place - for intensive care.

BURN FROM TREATMENT WITH CHEMICALS

On the leaves, areas of dead tissue appear, often pointlike (where the drops fell). Burns can appear if the drug is not diluted according to the instructions, or the leaves are especially sensitive to it. Burns are also likely if plants are treated in sunny weather - in modern preparations there is a substance that holds the solution on the surface of the leaf, which works like a lens in the sun. Use drugs according to the instructions and carry out treatments only in the morning / evening hours.


What diseases are found on gladioli

The main diseases of gladioli that occur on plants are divided into infectious and non-infectious. Often, infection occurs with seed or through the soil. Some pathogens are carried by pests that attack gladioli. As a result of damage, gladioli cease to bloom, severe damage leads to the death of plants. Therefore, the planted flowers are regularly examined in order to take the necessary measures in time, and they carry out preventive measures. It is necessary to know the signs of diseases and the types of pests that reduce the vitality of gladioli.

Gladioli are susceptible to diseases that affect all bulbous crops. But if these diseases are less dangerous for onions, then gladioli tolerate them harder. This is due to the constant work of breeders to improve varieties. Many modern species cannot be grown without the constant use of special means. Most of the pathogenic microorganisms that cause disease are found in the soil. Therefore, it is rather difficult to fight them.

The causative agents of diseases can be divided into groups:

  1. Viruses. Viral diseases spread in any region and cannot be completely cured.
  2. Mushrooms. Fungal infections often affect plantings of gladioli on acidic soils.
  3. Bacteria.

Plants are infected with spores or through the root system. Some gladiolus diseases develop on weeds, which are often the main vectors. In addition, the causes of gladioli diseases can easily be:

  • unfavorable climatic conditions
  • failure to comply with the requirements of agricultural technology
  • illiterate choice of variety.

Before you start growing and breeding gladioli, stock up on useful information about possible problems. The article will list the main pests, as well as diseases of gladioli and their treatment, a photo of each problem.


Varieties of diseases

Dahlias are susceptible to various diseases, most often they are fungal diseases. They develop in humid climates and provided that the grower has planted flowers very densely. Further, the most common of them will be described, as well as advice on how to deal with diseases and their consequences will be given.

Leaf spot

The fungus Entyloma dahliae is considered the causative agent of dahlia leaf spot. A symptom of the disease is yellow-green spots on the leaves.Subsequently, they blur and become gray-brown with a pronounced border. Poor ventilation between dahlia bushes due to densely planted plants leads to leaf spot.

To cure this disease of dahlias, fungicides are used. It can be Oxyhom or Fundazol. Healthy dahlia bushes are treated with these drugs, and diseased plants are destroyed.

Gray rot

The causative agent of gray rot, or, as it is also called, Botrytis, is the pathogenic fungus Botrytis cinerea. The first sign of the disease is the appearance of brown spots on the leaves, and then the whole plant is affected. Gray rot leads to drying of leaves, drying of buds and deformation of peduncles.

If botrytis infects dahlias during the flowering period, then water spots appear on the inflorescences, as a result of which the tissues soften and the flowers rot. The disease develops due to excess moisture, which is the result of a thickened planting.

In the fight against the disease, fungicides are used in the same way as in the previous case. It can be Topsin, Fundazol, Benleit or Rovral.

Verticillous and furious wilting

The symptoms of these diseases are the same, although the causative agents of the diseases are different - Verticillium dahliae and Fusarium oxysporum. First of all, the roots and tubers are affected, they simply rot. After that, the leaves and apices of buds and shoots wither. The affected dahlia is covered with a pinkish (fusarium) or brown (verticillium) bloom.

The cause of the disease is the same as in previous cases - a violation of ventilation and the presence of excess moisture due to a thickened planting. Affected tubers should be removed from the flower bed and burned. As a prophylaxis and treatment, plants should be treated with systemic fungicides. For example, Oxyhom or Fundazol.

Brown rot

The causative agent of this fungal disease of dahlias is the mushroom Rhizoctonia solani. As a rule, young shoots and dahlias at the beginning of the growing season are affected by brown rot.

The disease develops as a result of too deep planting of tubers. Fungicides are used as prophylactic and therapeutic agents. It can be Fundazol, Alirin, Fitosporin-M and Gamair.


Diseases of cucumbers

Cucumbers are extremely thermophilic plants, they do not tolerate too much moisture in the soil and excessive rainfall, many cold days when the temperature drops below 12 ° C, which occurs mainly during germination and the initial growth phase. A decrease in temperature below 10 ° C and an excess of moisture in the soil cause a complete inhibition of plant growth, mass death of seedlings.

Before flowering, nighttime temperature drops below 12 ° C cause cold damage with symptoms similar to powdery mildew. When growing cucumbers in cold and rainy years, diseases are a limiting factor in yield, even with intensive traditional protection. In dry and warm years, the most important factor in the success of growing these vegetables is the ability to water.

Downy mildew or downy mildew

The disease is caused by the fungus Pseudoperonospora cubensis.

Photo. Peronosporosis on leaves

Description

The disease causes a significant decrease in the quality and quantity of the crop. The symptoms of the disease vary by cultivar. A characteristic feature is rust on the cucumbers. The disease develops rapidly, causing the immediate extinction of the plantings of cucumber plants. In the southern and central parts of the country, the first symptoms of peronosporosis in varieties that do not show resistance to this disease can occur at the end of the third decade of June, and in varieties with high resistance - after 20-30 days (in mid-July).

Disease prevention

  1. Growing resistant varieties.
  2. Compliance with crop rotation - in one place you can grow cucumbers no more than after 2 years.
  3. Choosing a sunny, warm landing site. Garter plants so the whips don't lie on the ground.
  4. Reducing plant density by increasing the distance between bushes or rows.
  5. Gentle watering at the root, preferably in the morning. When watering in the evening, the drops of water do not have time to dry and remain on the plant overnight, which adversely affects the plant and promotes the development of the fungus.
  6. Prevention of this disease of cucumbers in the greenhouse and treatment includes mandatory soil disinfection, periodic soil replacement.
  7. Correct irrigation regime.

Preventive spraying with phytosporin and other drugs, including folk remedies.

Treatment of peronosporosis with chemicals

The correct protection of plants against disease is the use of fungicides with different mechanisms of action (contact, deep action and systemic preparations). Contact preparations form a protective layer on the surface of the plant and prevent the spore of peronospora from entering the leaf tissue. The deep-acting drugs are responsible for suppressing infection in the upper layers of leaf tissue. Systemic drugs are transported into the whole plant or part of it and provide protection in the rest of the plant.

A common mistake is refusing to use contact medications. When the infection is suppressed with deep and systemic remedies, the leaves will still show disease symptoms and, due to the specificity of the disease, will not be cured. In addition, the symptoms on the leaves reduce their assimilation surface and therefore reduce yield. That is why it is extremely important to carry out the first basic treatment against peronosporosis with contact preparations.

The most effective drugs:

  • Acrobat MC 69% at a dose of 2-3 kg per hectare (30 g / weave).
  • Infinito 687.5 at a dose of 0.2 l / ha (2 ml / hundred square meters) is a combination of two substances - propamocarb hydrochloride and fluopicolide. This product works systematically and deeply.
  • Ranman 480 - at a dose of 0.15 l / ha (1.5 ml / hundred square meters). A modern contact preparation contains a substance - ciazofid, used for prophylactic use.
  • Armethyl M 72 at a dose of 2.25 kg per hectare (22 g / hundred square meters) is a reliable systemic agent.

Photo. On the right side, the site is not protected, on the left, protected by the Infinito fungicide.

Fungicides are also used to destroy peronosporosis:

  • Ridomil MC - 25% s.c. 0.8-1kg / ha (8-10 g / weave)
  • Dove - 500 SC 2 l / ha (20 ml / hundred square meters)
  • Medzyan 50 WP 2.5-3 kg per hectare (25-30 g / are)
  • Copper oxychloride - 90% s.p. 2.4 kg per hectare (24 g / weave).

Spraying begins at the end of June and is applied every 7-10 days or after the first symptoms of cucumber disease appear. Resistant varieties are sprayed less often, every 10-14 days, with a dose reduction by about half.

Traditional methods

An effective way to fight fungus is to use horsetail extract or a preparation derived from yeast.

  1. Horsetail extract is prepared with 300 g of fresh horsetail (or 100 g of dried), which is placed in a large container with 3 liters of water and left for 24 hours. During this time, the solution is stirred several times and boiled for one minute, then cooled, filtered, diluted with water. The extract in this form is ready for spraying on plants.
  2. A yeast solution is prepared by dissolving yeast in water at a ratio of 25 g of yeast to 4 l of water. Plants are sprayed with the solution.

Cucumber bacteriosis

A common and dangerous disease that affects cucumbers in open ground and greenhouses. According to long-term observations, the threat of bacteriosis may arise as early as the third decade of June.

Photo of the leaves. Cucumber bacteriosis.

Description

The disease is caused by the bacterium Pseudomonas lachrymans, which overwinters on the seeds and debris of infected plants. During the growing season, the bacterium is carried by rain, insects and mechanically on tools. It infects cucumbers mainly at an early stage of development.

The disease in the early stages of plant development leads to a lack of fruiting, at later stages - to a decrease in yield, a deterioration in the quality of fruits.

Attention! Bacterial angular spots on cucumbers are easily confused with downy mildew due to the same period of onset of symptoms of both diseases.

A period of 10-14 days of sunny weather inhibits the development of the disease in the open field.

How to distinguish bacteriosis of cucumber from peronosporosis?

The first symptoms of peronosporosis are difficult to distinguish from bacteriosis. The main difference between the symptoms of both diseases is the loss of tissue affected by bacteriosis. With bacteriosis, small uneven holes appear on the surface of the leaf. The tissue on the leaves affected by peronosporosis does not crumble.

Prophylaxis

  1. seed dressing with apron 35% d.p. Dosage - 5g / kg of seed
  2. deep digging of soil in autumn
  3. correct crop rotation - in the old place, cucumbers are grown no more often than after 4 years
  4. cultivating cucumbers after mustard as a precursor reduces the occurrence of disease
  5. it is advisable to fertilize the soil with organic fertilizers, because cucumbers respond positively to the content of humus and organic matter in the soil
  6. removal of the remains of infected plants, fruits
  7. harvesting should be done after the dew has dried
  8. increased doses of potassium fertilizers (the rate of application of potassium sulfate for cucumbers is 1.5 kg for digging), even an excess of potassium is tolerated by plants well.As an alternative to potash fertilizers, manure can be added for digging in the fall at a dose of 600 kg per hundred square meters.

How to treat bacteriosis of cucumbers?

In April and early May, bacteriosis of cucumber in greenhouses is rare. Often, when growing a vegetable in greenhouses, farmers are overly concerned about the harvest, and in the beginning of spring they carry out many unnecessary and dangerous for plants and at the same time expensive treatments. Most often they are sprayed with copper preparations with the addition of various leaf fertilizers. The result of such treatment is often leaf burns (photo) or whole plants.

Photo. Symptoms of phytotoxicity of remedies for copper preparations on a cucumber leaf

Cucumbers during this period require, first of all, a large amount of heat and the correct application of mineral fertilizers, preferably multicomponent liquid fertilizers applied to the soil, and preventive irrigation with a fungicide.

Sprayers are used only when the first symptoms of the disease appear, using copper preparations 2-3 times from the appearance of 2-3 leaves to fruiting. The recommended remedy for treating cucumbers for this disease is copper fungicides.

It is worth recalling that copper fungicides in the EU countries are the only permitted measures to protect the integrated and organic cultivation of cucumbers from fungal and bacterial diseases. These drugs are the least toxic.

Copper preparations have a waiting time of 7 days and can only be used until the flowering period.

The following preparations are used for spraying cucumbers:

  • Bordeaux liquid - 0.5-1%
  • copper oxychloride
  • cuproxate
  • Champion 50 WP at a dose of 2.5-3 kg / ha (25-30 g / weave)
  • Medzyan 50 WP 2.5-3 kg / ha (25-30 g / weave).

In the early stages of growth, these preparations can cause yellowing of the edges of the leaves, which then disappears.

Cucumber powdery mildew

The disease develops on greenhouse cucumbers and in the open field. Caused by the fungus Erysiphe cichoracearum.

Photo. Affected leaves in a white powdery bloom

Description

Symptoms appear at the end of the growing season.

Prevention

  1. The correct choice of variety. It is recommended to grow hybrids of cucumbers resistant to powdery mildew - Brunet F1, Artek F1, Katyusha F1, Swallow F1, Alladin F1, Adam F1, Atlas F1, Courage F1, Bettina F1, Sort Phoenix, Nezhinsky.
  2. Early sowing.
  3. Deep digging of the soil.
  4. Treatment of cucumbers and soil around with sulfur preparations.
  5. Destruction (incineration) or treatment with formalin or lime-sulfuric decoction of affected plant residues.
  6. Maintaining optimal soil moisture, uniform watering.
  7. In greenhouses, sharp temperature fluctuations should be avoided, and regular ventilation should be carried out.

How to deal with powdery mildew on cucumbers?

Chemical control is rarely used. In rainy weather, spraying is carried out every 7-10 days after the first symptoms appear. The same means are used as for the fight against downy mildew. In addition to them, the following spray preparations are used:

  1. colloidal sulfur (0.2-0.5% - in the greenhouse, 0.5-1% - in the open field)
  2. copper-soap emulsion (7 g of copper sulfate and 100 g of liquid soap per bucket of water)
  3. karatan 18% 10-30 g / weave
  4. topaz 10% 1.5-2 ml / weave.

Spraying is carried out every 8-9 days.

Alternaria

The pathogenic factor - the fungus Alternaria cucumerina, rarely infects cucumbers.

Photo. Manifestations of alternariosis on affected leaves

Description

The disease appears later than peronosporosis and bacteriosis during warm and humid weather. With this disease, the leaves of cucumbers turn yellow.

Prevention and treatment

Similar measures are applied as for protection against peronospora.

Anthracnose

The disease caused by the fungus Colletotrichum orbiculare is very harmful. Cucumbers spoil badly during transportation and storage - they rot, become moldy. The disease is especially common in warm regions.

Photo. Signs of anthracnose damage to cucumber leaves and fruits

Description

The disease develops in humid climates. Infects greenhouse and ground cucumbers.

Prevention

  1. selection of disease resistant cucumber varieties
  2. seed dressing (5 g of apron 35% per 1 kg of seeds)
  3. destruction of plant residues
  4. deep digging of soil
  5. correct crop rotation.

Treatment

Chemicals are rarely recommended. If there are signs of the disease, the use of fungicides recommended for the fight against peronosporosis is indicated.

Several options for spraying cucumbers for this disease:

  • Bordeaux liquid - 1%
  • colloidal sulfur - 60 g / weave
  • copper oxychloride - 24 g / weave.

Cucumber cladosporium disease (olive spot)

The disease is caused by the fungus Cladosporium cucumerinum. The disease causes the death of the ovary during flowering.

Photo. Cladosporium disease of cucumber on leaves and fruits

Prevention

  1. It is recommended to grow cladosporium resistant varieties.
  2. The fungus hibernates in plant debris and seeds after harvest; it can persist for up to 2-3 years. It is necessary to thoroughly disinfect and destroy plant residues and dig up the soil. Any unhealthy plants and plant debris should be removed from the field and burned.

Treatment

The use of protective measures is the same as for the control of downy mildew. Chemical protection is not recommended when growing resistant varieties.

Cucumber mosaic

The viral disease is caused by the Cucumis mosaic virus (CMV). Infected fruits are not tradeable.

Photo. Cucumber mosaic - damage to fruits and leaves

Description

The first symptoms appear 6 weeks after sowing the seeds.

Prevention and treatment

  1. It is recommended to cultivate cucumber varieties genetically resistant to the cucumber mosaic virus.
  2. Disinfection of seeds - heating at 50 degrees for 3 days, then at 80 degrees for a day.
  3. Infected plants are pulled out, destroyed.
  4. It is not recommended to grow cucumbers with plants susceptible to this disease:
    • tomatoes,
    • peas,
    • celery,
    • tobacco.

Sclerotinia or cucumber white rot

The disease has been a major problem in cucumber cultivation for many years. The causative agent is Sclerotinia sclerotiorum.

Description

Prevention and treatment

  1. The fungus survives in the soil for 7-12 years, but germinates at a depth of no more than 8 cm. Therefore, it is recommended to carry out deep plowing (digging) in the fall.
  2. Requires constant ventilation of greenhouses, greenhouses.
  3. The fungus should not be allowed to enter the soil. Early removal of infected plants or their parts and thorough cleaning of plant residues after cultivation are carried out.
  4. The disease cannot be defeated with a traditional fungicide, therefore an integrated treatment system must be applied. Several weeks before planting, you can use Contans XX, which contains the antagonistic fungus Coniothyrium minitans.

Fusarium wilting

The disease often manifests itself not only in adult plants, but also in their seedlings, which die off. The infection can persist in soil, seeds.The causative agent of the disease is a polyphagen with a very large number of hosts. It is found on cucumbers in open ground, in greenhouses, hotbeds, often destroys entire plantings.

Description

Prevention and treatment

  1. correct crop rotation - pumpkin plants can be planted in the same place after 5 years
  2. good predecessor - alfalfa
  3. destruction of plant residues
  4. deep digging
  5. application of fertilizers with increased doses of phosphorus, potassium.

Black stem rot

Black rot of buds and shoots of cucumber, caused by the pathogen Mycosphaerella melonis. The fungus produces 2 types of spores: Didymella bryoniae and Phoma cucurbitacearum. Spores germinate in 4-8 days. Several generations grow during the growing season.

Description

Preventive actions

  • maintaining air humidity in the greenhouse below 80%
  • irrigation should be adapted to weather conditions, reduce irrigation with a low load of bushes with fruits
  • leaves are cut equally, perpendicular to the stem
  • disinfection of instruments
  • avoidance of sudden changes in microclimate.

Root rot

The disease is common in greenhouses and greenhouses.

Description

This disease is complex, it occurs when the roots of a cucumber are affected by unfavorable weather conditions and soil fungi settle on them.

Prevention and treatment

  • observance of crop rotation
  • soil disinfection
  • hilling roots
  • watering with warm water (water is heated to 20 degrees)
  • rational fertilization and feeding.

When the disease has already appeared, you can bend the stems to the ground and create horizontal layers, sprinkling them with earth, additional healthy roots are formed in the stems through which the bush will feed.


Plant diseases. Scab, causes and methods of struggle

I will continue the series of articles on plant diseases with a story about scab. I have already told about the prevention of various rot, today I will talk about methods of dealing with scab, a dangerous fungal disease that has a fast spreading rate and affects mostly fruit trees.

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Vyacheslav Gennadievich Turkovsky

When I first bought a laminate floor, I studied the technologies for manufacturing laminated products and came to the simple conclusion that there is nothing more practical than an array.


Why cucumbers get sick

There are several reasons why cucumbers in the country can get sick. Knowing them, you can prevent or reduce the consequences.

A diseased plant can be a hassle.

One of the main factors in the occurrence of unpleasant sores is non-observance of the temperature regime.

Changes in temperature, including day and night, as well as high humidity, watering with very cold water are favorable causes of infection.

It is important to observe crop rotation in the beds. Cucumbers can be returned to their original planting site no earlier than four years later .. Lack of light, the presence of drafts, untimely feeding also make the cucumber culture vulnerable to a number of diseases.

Lack of light, the presence of drafts, and untimely feeding also make the cucumber crop vulnerable to a number of diseases.

Timely identify and remove the affected parts of diseased bushes.


Watch the video: Plant Health u0026 Disease Troubleshooting Guide


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