The tomato is one of the fruit vegetables that young and old particularly appreciate. Gardeners like to grow different varieties. But some very specific diseases can attack tomato plants despite all the good care given to them. Let’s take stock of the four main tomato diseases, ways to treat them (when possible) and also see how to avoid them.
Common Tomato Diseases, Symptoms and Treatments
Viral, bacterial or fungal diseases can devastate an entire crop of tomatoes. Many factors are involved, namely:
- humidity,
- Temperature,
- The wind,
- The vulnerability of certain varieties,
- Soil infertility.
Four diseases are particularly recurrent in tomatoes and can be identified by certain symptoms.
1 – Septoria leaf spot
It is a fungal disease that specifically attacks tomatoes. Very devastating, it destroys the leaves. Identifiable at first by rounded spots first appearing on the leaves close to the ground, it then spreads throughout the leaf system. The leaves turn brown, dry up and fall off. There is not much you can do to save your bed of tomatoes when the disease is very advanced. It is therefore necessary to react very quickly at the first symptoms by treating with an organic copper-based fungicide.
2 – Fusarium wilt or Fusarium wilt
This is a fungal disease more common in hot climates that can devastate an entire crop of tomato plants. The whole plant can wilt and die. It is essential to use a biological fungal treatment, but if the infestation is very important, the only solution is to uproot all the plants.
3 – Mildew
Downy mildew is caused by a pathogenic fungus. It is quickly identified by the appearance of brown spots on the foliage, yellowing and then leaf fall. It is the most common tomato disease. We treat with a fungicide based on sodium bicarbonate or even based on copper.
4 – Brown rot or bacterial wilt
This bacterial disease is caused by the bacteria Ralstonia solanacearum. The leaves wither and fall after they have completely dried out and the stems are marked by large brown mottling. Note that it is always the youngest leaves that are attacked before the others. You can see that a slimy film oozes from the stems when they are cut. Unfortunately, this disease is spreading at lightning speed on many vegetable plants. All infested tomato plants must be uprooted as soon as possible. Currently, there are no products available to treat brown rot.
Prevent tomato diseases
To avoid problems caused by common tomato diseases, it is essential that the gardener follows the following recommendations.
- Select resistant varieties.
- Always respect the needs of plants, both in terms of exposure, soil and watering.
- Never overtighten your plants because you must allow air to circulate within a bed but also in the heart of each plant in order to avoid as much as possible the excess of confinement which promotes fungal diseases (or cryptogamic diseases) .
- Opt for the rotation des cultures which consists of not growing the same vegetables in the same place, several years in a row.
- At the slightest sign of disease, eliminate all the affected parts or even the complete plants and burn them to avoid contaminating other plants, since certain pathogenic organisms can live for several years in the soil.
- Disinfect all the tools used to prune the tomato plants as well as the containers in which you wish to transplant the seedlings if the project is to grow tomatoes in pots.
- Limit the risk of fungal diseases by taking care not to wet the leaves of the tomato plants when watering and protect the foliage from splashes of rainwater by suitable mulching.
- Practice companion planting as soon as possible, i.e. plant friendly plants near the tomatoes that repel parasites and avoid certain diseases such as basil, New Zealand spinach, marigold, the lettuce, cucumber, cabbage, chives, marigold, carrot, garlic…
By adopting all these good habits, you can protect your crops against many diseases and benefit from an abundant harvest of excellent quality tomatoes. But these tips remain valid for all vegetable plants. It should be noted, however, that all tomato-friendly plants are not necessarily associated with all the plants in the vegetable garden. It is necessary to inquire well beforehand in order to opt for the good associations.