How to combat tomato powdery mildew?

Powdery mildew is a disease caused by fungi that causes serious damage to a wide variety of plants, including the tomato plant. However, although it may seem just the opposite, it is actually not very difficult to treat … as long as it is detected early.

So if you want to know how to eliminate tomato powdery mildew and/or how you can prevent its appearance, then we will explain in detail everything about this disease.

What is it?

The mildew is a parasitic fungus that attacks the aerial parts of the plant (leaves, stems and fruits). The species that affects our tomato plants is known by the scientific name Leveillula taurica . It is easy to distinguish since as soon as it infects plant beings, they soon become covered with a cottony layer of gray-whitish to white mycelium, which we call gray dust or mold.

The optimal conditions for its development are a temperature of 20 to 25ºC and a relative humidity of 50 to 70%. For this reason, it is during spring and summer when we can see it, coinciding with the tomato planting, growing and harvesting season.

What are the damages / symptoms it causes?

Powdery mildew affects tomato

Image – Flickr / Scot Nelson

The damages or symptoms it causes are the following :

  • White and powdery spots on the upper part of the leaves that increase in size and turn yellowish.
  • Whitish powder on the underside of the leaves and / or on the fruits.
  • Premature death of the leaves.
  • Growth arrest.

How can tomato powdery mildew be cured?

To eliminate tomato powdery mildew we recommend doing the following:

Next, if we have the plants in pots, it will be convenient to take them and take them to another area , away from the other plants. This is very important to prevent others from catching it. Likewise, if they have very affected parts, for example, if they have tomatoes that are already excessively soft or rotten, or leaves full of mold, then we will cut them with previously disinfected scissors.

And finally, we will water only when necessary . Tomatoes are plants that want a lot of water; in fact in summer they may need a daily watering, but an excess of water can be fatal. For this reason, it is important that the soil in which they grow has good drainage, and that if we have them in pots with a plate underneath, we do not keep said plate always full of water.

Nor should their leaves be sprayed / sprayed , except if we live in an area where the humidity is low, less than 50% (we can find this out by consulting any meteorology website. For example, if you are in Spain you can Google something like : AEMET X (changing the X by the name of your town or city) and then you would have to give it to See detailed table, and you could see what the relative humidity is in your area).

How to remove powdery mildew from tomato plants naturally?

Sulfur and copper alone are already good ecological fungicides. You simply have to sprinkle them on top of the leaves, as well as on the soil around the stem of the plants. Now, there are also other natural products that you can use, such as horsetail, whose extract you can buy ready for use, or make it yourself by preparing an infusion with a liter of water and 100 grams of plant. You leave it boiling for ten minutes, and then you wait for it to cool down before using it.

Another product that you probably have at home and that will also help you fight tomato powdery mildew is baking soda. This is a good fungicide, which also has antibacterial and antiseptic properties. To use it you have to mix 1 liter of water, 2 tablespoons of olive oil, and 2 tablespoons of bicarbonate, and spray the plant with it. But yes, as a precaution it is highly recommended to first take a sheet to see how it reacts.

Can you prevent powdery mildew in tomato?

Tomatoes can have powdery mildew

Tomato powdery mildew can leave us without a harvest, hence it is necessary to take some measures to avoid its appearance. Although they are not infallible, they do help prevent it. They are as follows:

  • Pluck wild herbs.
  • Eliminate the affected leaves and / or fruits.
  • Treat the plant with copper-based fungicides, which we will find in garden stores or nurseries, as soon as we see the first symptoms.
  • Keep the tomato plants well cared for; that is to say, water them very often so that they do not go thirsty and fertilize them with organic fertilizers throughout the season.
  • And of course, we do not have to buy sick specimens as they could infect the rest.

As you can see, tomato powdery mildew is a disease that can be serious, but it can be treated with effective products.

How to combat tomato powdery mildew?

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