Fungal diseases of plants: what it is and examples

Plant cryptogamic diseases represent the majority of phytopathologies

As many of you already know, plants not only suffer from pests, but they can also suffer from various diseases. There are different types. They are usually distinguished by the pathogen that causes them. In this article we will talk about fungal diseases of plants. This term may not sound familiar to you, but some of these conditions are.

We will not only explain what fungal diseases of plants are, but we will cite some examples, such as anthracnose or botrytis. So, if you want to know more about this type of pathology, I recommend that you continue reading.


What are fungal diseases?

Cryptogamic plant diseases are diseases caused by fungi or other parasitic filamentous organisms.

Before giving examples, we will first explain what plant fungal diseases are. These are diseases caused by fungi or other filamentous parasitic organisms, as the oomycetes. When animals are affected, this type of disease is called “mycosis”.

But what is the curious name “cryptogamic” due to? Well, fungi and other filamentous organisms have been classified as cryptogamous plants. It is for this reason that the diseases they cause are known as fungal diseases. The forms in which these pathologies present themselves are very diverse, representing about 90% of all phytopathologies, or plant diseases.

Evolution of plant fungal diseases

With regard to the evolution of fungal diseases in plants, contamination occurs first. The spores belonging to the cryptogamous fungi are transported, by the wind for example, to the plants, where they are deposited. There they begin to germinate and eventually penetrate inside the plant tissues.

The attacking fungus passes through the stomata and lenticels, which are natural openings in plants. It usually even has the ability to cross the cuticle! You can also access the inside of the vegetable by wounds available to the plant in question. These injuries can be caused both by insects and by ourselves, not being careful when handling the vegetable.

Once the contamination of the plant is over, move on to the next phase: Incubation. This is when the fungus begins to branch out and invade plant tissue cells or the spaces between them. Then the first symptoms begin to appear, which eventually develop gradually. These are accompanied by the fruiting of the fungus.

Plants attacked by fungal organisms may languish. In other words: They may suffer from obstruction of vessels, tissue necrosis, etc. When it comes to fighting these types of diseases, Fungicides are often used because they are usually fungi that invade plants.

Here we will talk about some examples of plant fungal diseases, I’m sure some of the others sound familiar to you.


First of all, we have the famous anthracnose, also called chancre or chancre. It is very common in humid and warm regions. The fungus responsible for this disease generally belongs to the genus Gloeosporium Where Colletotrichumor be part of the species Coniothyrium fuckelii.

Anthracnose can infect various plants, herb trees. Affected plants may exhibit a variety of symptoms, such as the following:

  • Sunken spots on the leaves with a wet appearance and various colors.
  • Necrosis in the nerves of leaves, flowers, fruits and stems.
  • tissue death and wilting (following necrosis).

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Anthracnose, one of the fungi that most affects plants

On many occasions, anthracnose initially appears in cuts made during stem grafting. It also usually begins to manifest itself in wounds caused by pruning. So we have to be very careful while performing these tasks. If we suspect that our plants may be infected with these fungi, Treatment should be started as soon as possible to control the disease. To prevent its appearance, it is best to use seeds that are resistant to this type of fungus.

If our vegetables are already infected, we can try various treatments to control anthracnose:

  • Destroy plant tissues that are affected by the fungus.
  • Apply fungicides.
  • Fight pests and insects that spread this type of fungus.
  • Natural remedies: Apply horsetail or nettle porridge, or use homemade fungicides made from milk, garlic and baking soda.


Another fungal disease of plants is Botrytis cinerea, also known as botrytis. This time it is a fungus belonging to the genus Botryotinia of the family Sclerotiniaceae. Specifically, the species that causes this disease is the Botryotinia fuckeliana. This fungus not only affects plants, but also animals and bacteria. This, yes, its favorite host is the vine.

As with most fungi, the risk of infection is greatly increased when the environment is hot and humid. Botrytis is also known as gray mold because one of its most striking symptoms is the appearance of a kind of grayish powder on the plant.

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While it’s true that botrytis is a fairly simple disease to tell apart, it can be somewhat difficult to recognize at first. To help you in its detection, we will see below symptoms caused by the fungus Botryotinia fuckeliana:

  • Leaves that turn brown and eventually fall
  • Slowing of the overall growth of the affected plant
  • Stems adopting a soft or rotting composition
  • Flower death and abortion
  • Fruits that turn dark brown or even black and eventually drop
  • Appearance of the characteristic grayish powder on fruits, leaves and stems


Downy mildew is the name given to various fungal diseases of plants.

Downy mildew is the name given to various fungal diseases of plants. These are all those caused by oomycetes belonging to the family Peronosporaceae. But what are oomycetes? The name means “egg fungi” and they are basically a group of filamentous protists that are part of the pseudofungi group. These pseudofungi are types of mold very similar to true fungi. However, they are not related to them.

Late blight fungal diseases are spread by spores. They usually appear during periods of rain and with high temperatures, that is, above 25 degrees. With these optimal conditions, this pest or disease spreads very quickly. The oomycetes responsible for downy mildew they grow in the fruits, in the stems and inside the leaves of the plants.

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How to detect mildew? This disease is characterized by the appearance of slightly greenish spots that eventually turn yellowish or even brown on the upper side of the leaves. In exchange, a grayish type of down usually appears on the underside. As a result, the leaves dry out and eventually fall off the plant. Unlignified stems can also be affected. Fortunately, there are products to fight mold.

Among the mildew diseases, the best known is Plasmopara viticola, which generally attacks the vine. Other common species are Peronospora farinosa, which mainly affects spinach; the P.manshurica, which primarily infects soybeans; and others that harm various vegetables such as potatoes, tomatoes, onions, lettuce, etc. In none of these things crop yields are greatly reduced.

powdery mildew

Another cryptogamic plant disease should also be highlighted: powdery mildew, also known as powdery mildew. This time, the fungus responsible for the pathology is the Uncinula necator. As this disease progressesthe leaves of affected vegetables turn yellow and eventually dry out. However, the most characteristic symptoms are:

  • White or gray coating like ash, which covers the leaves.
  • Appearance of whitish spots resembling dust.

One of the areas most prone to powdery mildew It is the Mediterranean region. There, all the conditions for an optimal development of the fungus are met: Low temperatures, high humidity, poor ventilation, stale air, low light and excess nitrogen. All of these factors facilitate the spread of powdery mildew.

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powdery mildew

As soon as we detected the first symptoms of powdery mildew, Infected leaves should be removed as soon as possible. In addition, it is very practical to improve the aeration of the plant and the orchard in general. For this we can resort to the pruning of vegetables and remove some plants, in case the density is high. If we don’t act, powdery mildew will continue to spread. As a result, plant growth will slow down and leaves will turn yellow and die.

When it comes to controlling this fungus, there are several spray treatments that can be applied to the leaves. They are:

  • Use half a liter of skimmed milk for 8 liters of water. This treatment is very effective.
  • Dilute 75 milliliters of hydrogen peroxide in five liters of water.
  • Sulfur: It can be used in aqueous spray or powder given with bellows. Of course, it should never be applied during the flowering season.

These are just a few examples of the most well-known fungal plant diseases. There are many more and its rapid recognition is essential to be able to save the harvest.

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