Anthracnose in tomato: What are its symptoms and how to treat it

Anthracnose in tomato is caused by a fungus

Anthracnose in tomato is caused by a fungus

There are many diseases and pests that can affect our crops, which also includes tomato plants. One of the most common pathologies in these fruits is one caused by fungi, known as anthracnose. To learn more about tomato anthracnose, we will discuss its symptoms and how to treat it.

If you are growing tomatoes and want to prevent them from being affected by the anthracnose fungus, I recommend that you keep reading. We will explain what this disease is, what its symptoms are, how to treat it and most importantly: How to prevent anthracnose in tomato. So take note to prevent your crops from being affected or even detect if they are already infected by this fungus.

What causes anthracnose?

Anthracnose in tomato kills the fruits

Anthracnose in tomato kills the fruits

Before explaining the symptoms and treatment of anthracnose in tomato, we are going to comment on what this disease is. The agent responsible for this phytopathology is a fungus called Colletotrichum gloeosporioidesbut it can also be caused by other species belonging to the genus Colletotrichum, Gloesporium y Coniothyrium Coming from the Greek, the word “anthracnose” translates as “coal” and is a limiting disease for various fruits, such as tomatoes or papayas, affecting their shelf life.

This type of fungi is characterized by having spores or reproductive structures called conidiyou. They are arranged in acervuli that in turn participate in the plant infection process. When it comes to colonizing the plant, there are two phases:

  1. Initial or biotrophic phase: The fungus feeds on the plant, specifically its living cells. Thus, the pathogen ends up establishing itself in the plant.
  2. Second phase or necrotrophic phase: Due to the attack of the pathogen, the resources obtained now come from dead cells. It is in this phase that the first symptoms of anthracnose appear.

The chances of anthracnose appearing in tomato increase considerably when the plant has wounds, whether they are caused by some nutritional imbalance, by blows, by friction or by insect attacks. Another factor that favors the appearance of this fungus is the heat. Therefore, this disease usually appears in summer and even in spring. Too humidity enhances the fungus. Those climates whose humidity exceeds 90% or that have a lot of rain and wind considerably facilitate the spread of the fungus and the dissemination of its spores.

Symptoms of anthracnose in tomato

To detect anthracnose in tomato, we must pay attention to the plant and be attentive to the appearance of the symptoms of this disease. Among them stands out the appearance of brown spots on the leaves, specifically around the nerves. When it is still in its initial state, first they are small, circular spots. Over time they darken until they cause the death of the tissue, which is known as necrosis.

We can also observe symptoms in the fruits of the vegetable, especially in those that are in the process of maturation. In this case sags and dark lesions appear on the surface of the tomato. As a consequence, the whole fruit ends up rotting prematurely.

How is anthracnose controlled?

There are treatments and prevention measures for anthracnose in tomato

There are treatments and prevention measures for tomato anthracnose

If we have detected symptoms of anthracnose in tomato, we must treat the entire crop with post-harvest fungicides. In addition, it is very important to remove all affected parts, whether they are leaves, stems or fruits. It is very important to remove all crop debris affected by the fungus, as they are a means of propagation of the fungus. The mycelia of the pathogenic agent can continue to be active after two years or even more.


Although there is a treatment for anthracnose in tomato, it’s better to prevent than to cure. For this reason, we are going to give you some advice to prevent your plants from being affected by this fungus:

  • Before planting the vegetable, first disinfect the soil.
  • Prevent the soil from flooding when watering.
  • Improve soil drainage.
  • If we are in an area with a climate and environment that favors the appearance of anthracnose, space the plantation frames.
  • Remove wild weeds.
  • Avoid increasing the density of the pathogen in the soil.
  • Avoid monoculture.
  • Do not wet the parts of the plant that are in the air, such as stems, leaves and flowers.
  • Always clean pruning tools, both before and after using them. For this we can use a few drops of dishwasher or pharmacy alcohol.
  • When watering, avoid doing it from above so that the water does not splash the upper part of the plant.
  • Prevent healthy tomatoes from coming into contact with the soil.
  • Use postharvest fungicide treatments, just in case.

As you can see, tomato anthracnose is a fairly serious disease for the crop, but with a simple solution. Nevertheless, It is best to take all possible measures to prevent that this fungus, or any other, could end up infecting our crops.

Anthracnose in tomato: What are its symptoms and how to treat it

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