Recognizing and controlling cucumber diseases | 10 diseases of cucumbers

Bacterial soft rot primarily affects young fruit. These become soggy from the beginning of the blossom and smell rotten. Recognizing the rot is important so that other fruits on the plant are not affected. Because direct combat is not possible, as sprays against these bacteria have not yet been approved. If the rot is therefore detected, the following steps should be taken immediately:

• remove affected fruit immediately
• never water from above
• even the smallest splashes of water could be the cause
• Bacteria are present in the water
• reach fruit through the smallest wounds

powdery mildew

Cucumber plants are unfortunately very susceptible to fungal attack. This also includes powdery mildew, one of the most aggressive types of fungus, as it is almost impossible to combat. If a cucumber is attacked by powdery mildew, this usually means the end of the plant. Since these are edible vegetables, there is no effective spray agent approved for kitchen gardens against powdery mildew infestation. The infestation can be recognized as follows:

• dry and warm weather ideal for infestation
• possible in greenhouse and outdoors
• white coating on the leaves
• first spotty
• later extensively
• leaves die off
• Plant dies altogether

If you recognize powdery mildew on a cucumber plant , you should remove it immediately and dispose of it in the residual waste, as it is impossible to combat it. In this way, however, one can possibly prevent further spread to the adjacent plants.

Angular leaf spot disease

If the plant is attacked by the bacterium “Pseudonomas syringae pv. Lachrymans”, the fruit will rot. The cucumber disease that occurs here is called angular leaf spot disease. The infestation is favored by high humidity and high temperatures of over 24° Celsius. These diseases are particularly common in a greenhouse that is mainly exposed to the sun. The following steps should be taken to identify and combat the infestation:

• yellow, glassy, ​​angular spots on leaves
• enlarge
• turn brown, dry up
• Holes form on the leaves
• Fruits get mushy spots
• dark with white central dot
• Bacterial slime is secreted on both
• Remove plant altogether
• not to be saved
• cultivate resistant varieties such as “Flamingo” or “Saladin”.

If a cucumber plant with the pathogen was cultivated in the garden and the weather conditions caused an outbreak, then neither pumpkins, courgettes nor cucumbers should be cultivated on this bed for the next three years in order to eradicate the bacterium here again.

Grauschimmel

If there is a gray coating on the leaves, then it is usually gray mold. Stems, leaves and fruit bases are equally covered here. The spores survive in the soil and spread whenever there is dew on the cucumber plants and in generally wet weather. Usually, however, already weakened plants are attacked by the gray mold. The infestation can be prevented or combated as follows:

• good air circulation
• especially in a greenhouse
• Avoid splashing water on leaves
• only water at the roots
• at first infestation, remove shoots and leaves
• ensure less humidity
• maybe replace the floor
• here the fungal spores survive
• dispose of old soil in the residual waste

If the fruit is already affected, then the plant can no longer be saved, because fungicides must not be used in a kitchen garden. If the bed is prepared for the following year, the soil should always be replaced.

cucumber aphids

Cucumber aphids are not only a nuisance, they are also carriers of the viruses responsible for cucumber mosaic virus. Therefore, if only a few aphids are recognized on the cucumber, they should be combated immediately. Otherwise, the cucumber diseases that then occur could cause major damage to the plants that can no longer be repaired. The harvest then fails that year. Combatting cucumber aphids is therefore as follows:

• choose natural fines
• Larvae of lacewings and ladybirds
• hoverflies
• Wash cucumber plants
• spray with soapy water
• pay attention to air circulation
• this allows plants to dry off again
• repeat several times
• do not use insecticides

cucumber mosaic virus

The cucumber diseases also include the cucumber mosaic virus, which also affects zucchini, pumpkins or melons and many other vegetables and ornamental plants. The viral infection is transmitted by aphids. It is therefore important to fight the aphids directly so that there is no virus attack that looks like this:

• Symptoms at high temperatures
• light green or yellow mosaic discolouration
• especially young leaves deform
• get bumps
• Fruits get spots or warts
• also wilting or undergrowth of the plant
• occurs at cooler temperatures

Harvested and unaffected fruit can usually be eaten. There is no suitable remedy for the disease.

cucumber wilt

If the cucumber suddenly shows wilted leaves despite sufficient watering, this could be due to one of the cucumber diseases, the so-called cucumber wilt. The plants are attacked by a soil fungus, Fusarium oxysporum. The fungus is in the soil, is absorbed with the irrigation water via the roots and thus clogs the pathways from the inside. As a result, the cucumber no longer receives enough liquid in the upper part and begins to wilt. Cucumber wilt can be recognized as follows:

• often at the same time as root rot
• pink down at base
• between stem and soil
• Remove affected cucumber plant immediately
• Exchange soil generously
• Disinfect soil around other plants
• Plant cucumbers directly into a grow bag
• fill with substrate from specialist shops
• Cucumber has no direct contact with the ground

Minierfliegen

Leaf miners are not a cucumber disease, but they are annoying and harmful. Females lay hundreds of eggs per generation. The larvae eat the leaves, weakening the plant for viruses or bacteria to invade and making it susceptible to disease. Ichneumon wasps, which are available in well-stocked specialist shops, can be used against leaf miners.

Sclerotinia-Which

If the cucumber plants are cultivated in a greenhouse, Sclerotinia wilt, which is a classic greenhouse plant fungus, is more likely to occur. This fungus grows anywhere that is cool and extremely humid. You can recognize Sclerotinia wilt by the following symptoms:

• cottony turf of fungal spores on stems
• with small black globules
• outer leaves turn yellow
• start zu which
• later the fruits are also affected
• Remove the plant promptly if an infestation is detected

The cucumber can no longer be saved from these cucumber diseases caused by the fungus. It is only possible to prevent an infestation on the surrounding plants. Therefore, the soil should be completely replaced in the entire cucumber bed. Alternatively, disinfecting and chopping also helps. Planting garlic in the cucumber bed can also protect against infestation.

spider mites

Spider mite infestation can be very damaging to cucumber plants. The pests appear mainly in dry and warm weather and settle on the leaves. These react immediately with damage, in that the upper side shows small yellow dots and the leaves later dry up altogether. The underside is covered with a white net. As a result of the damage, the plant loses its strength to form cucumber fruits, especially when this occurs massively. Therefore, in the event of a spider mite infestation, a harvest will fail if you do not fight it. This should be done as follows:

• Spider mites very small
• usually not visible to the naked eye
• only from damage to leaves
• Cycle of propagation only one week
• many generations in one season
• Use predatory mites and lacewings
• helps especially with cultivation in a greenhouse

Conclusion
Unfortunately, there are many cucumber diseases that can affect the plant before harvest. These include various fungal diseases that must be avoided. Because once the cucumbers have been attacked by one or the other fungus, they can usually no longer be saved, since effective measures are not permitted in a kitchen garden and therefore may not be used. It is therefore important that you create the living conditions for the plants with ideal care so that a rich harvest can also be guaranteed.