Cucumber Diseases: [Characteristics, Types, Detection and Treatment]

What are cucumber diseases and how can we detect them?

Cucumber belongs to the Cucurbitaceae family and is one of the most appreciated vegetables in world gastronomy, since it serves as both fresh and industrialized food.

However, there are many diseases that attack this crop, some caused by parasites, fungi, bacteria and even viruses that cause serious damage to the plant.

One of the parasitic diseases that affects cucumbers is Oidiopsis, which appears as yellow spots on the upper side, causing necrosis in the center and showing a kind of whitish felt on the underside.

Among the cucumber diseases that are caused by fungi are: powdery mildew of cucurbits, mildew, Botrytis, white rot, gummy canker; Root and stem rot and Anthracnose that affect the leaves and flowers.

They also infect some cucumber crops such as Watermelon Necrotic Spot Virus type 1 and 2, Zucchini Yellow Mosaic Virus; Cucumber Mosaic Virus and Cucumber Yellow Vein Virus.

Viruses cause necrotic lesions and are seen as dark green spots along the veins of the leaves, smooth deformations on the leaf blade. They are generally combated by removing weeds and aphids.

When the cucumber is affected by some type of virus, it presents the yellowing of the veins of the leaves and a mosaic, light-green, dark-green, is produced in the fruits.

Description of cucumber diseases

Cucumber cultivation is attacked by the following diseases:

Oidiopsis

Caused by Leveillula taurica, which is a semi-internal development parasite whose conidiophores come out through the stomata, causing yellow spots and, in extreme cases, drying the leaves.

powdery mildew of cucurbits

Also called «Ceniza» is a disease caused by Sphaerotheca fuliginea, which is spread by spores that are carried by the wind.

This fungus reproduces with favorable temperatures that are in a range of 10-35ºC, with the optimum around 26ºC.

Mildew (Pseudoperonospora cubensis)

This fungus is a parasite that needs free water to disperse its spores.The development of the fungus is favored by the alternation of hot temperatures. Night dews and morning mists also favor its development.

gray rot

Caused by Botrytis cinerea, it attacks a large number of plant species, including cucumber, affecting all protected horticultural crops, being able to behave as a parasite and saprophyte.

On cucumber leaves and flowers it leaves brown lesions. A soft rot (more or less watery, depending on the tissue) takes place in the fruits, in which the gray mycelium of the fungus is observed.

white rot

It is generated by the fungus Sclerotinia sclerotiorum that directly attacks the cucumber stem and generally causes the plant to collapse and die quickly.

The disease starts from soil sclerotia from previous infections, which germinate under conditions of high relative humidity and mild temperatures, producing a variable number of apothecia.

Gummy stem canker (Didymella bryoniae)

It directly affects the cotyledons, which end up drying out, producing lesions in the area where they join the stem.

In cucumber cultivation there are attacks on the fruit, which are characterized by strangulation of the area of the stylar scar, which is covered with pycnidia.

Root and stem rot

Produced by Fusarium solani fs cucurbitae, which attacks the root and the base of the stem where a dark lesion can be seen that hangs the plant.

Anthracnose (Colletotrichum orbiculare)

It affects the leaves and flowers and can also cause lesions on the fruit.On the cucumber plant, moist brown spots are observed that spread throughout the leaf blade.It can attack both foliage and fruits.

How to identify and eliminate cucumber diseases?

Cucumber cultivation is of great importance, which is why it is necessary to know how to identify the conditions caused by bacteria, fungi and viruses to determine controls and methods to eradicate them.