What is phytophthora and how can you fight it

Posted By: Adrian Medina

You have wilting plants and you don't know why. Although you water them, they don’t get better. You would even say it is making it worse. 

If it has ever happened to you, it is very likely that your garden has been affected by the phytophthora fungus. A very dangerous and difficult to treat variety of fungus, which can remain dormant for a long time in the roots of plants. 

The phytophthora extends through the host plant to death and contaminates the soil in which it was planted. Once the fungus has developed, it is almost impossible to eliminate it. 

But keep calm. If you catch it at an early stage of the disease, it is still possible to save the plant. 

In this article we are telling you how you can prevent the appearance of phytophthora and we are giving you some tips to detect it in time. Do you want to know more? Keep reading. 

What are the symptoms of phytophthora?

In the early stages of infection, it is easy to confuse the symptoms of phytophthora with the lack of irrigation. But these simple guidelines will help you distinguish it: 

Affected plants do not improve with irrigation: At first, it may appear that the species infected by the fungus are lacking water. The leaves turn brown, yellow or red and end up wilting. However, no matter how much we water them, their condition does not improve. 

Brown spots appear on stems and roots: With the attack of the fungus, rot marks appear on the roots of the plant and at the base of the stem. This can give us a clue that our plant is being infected. 

It only affects plants in soils with poor drainage: If the only plants that have symptoms of drought are those that are in soils with waterlogging, it is most likely due to the attack of the fungus. This point is key to detect it in time and eliminate it. 

The fruits rot: In the case of fruit trees, we will see brown areas appear, with an appearance similar to leather, on the surface of the fruits. These spots end up rotting all the fruit. 

Gomosis: Trees affected by phytophthora exude a sticky amber substance through their bark, which is known as gummosis. 

Which plants are more sensitive to phytophthora? 

Almost any plant can suffer the attack of phytophthora. However, these varieties are especially sensitive: 

Conifers: Dryness extends from the base of the trunk to the top. The branches turn brown, as if the tree was drying. 

Citrus and fruit trees: Lemon, avocado, peach tree ... These species are usually targeted by the phytophthora. We will notice it by the appearance of brown spots on stems, leaves and branches, and by the rot of the fruits. It is also common for gummosis to occur. 

Lawn: Freshly sown and poorly drained grass is the most susceptible to the phytophthora fungus. 

Once the fungus has spread throughout the plant, there are no products that can completely eliminate it. Therefore, the best weapon against phytophthora is prevention. 

How is phytophthora prevented?

These are the guidelines you should follow to prevent your plants from being affected by the fungus: 

Well-drained tree

Like most fungal diseases, phytophthora thrives in moist soils. It infects the plant through the water absorbed by the roots. 

To avoid it, we must always ensure that the soil has good drainage and no waterlogging. 

Water moderately

Excessive irrigation can be fatal to our plants. We will avoid overwatering them. 

Use disease resistant rootstock Some varieties of fruit trees have a natural resistance to phytophthora. Use them as a rootstock of a weaker variety to protect it. 

Some species of fruit trees that you can use are: 

• Trifoliate orange and hybrid varieties of this tree 

• Pomelo and tangerine hybrids 

• Sour orange 

Fungicide Mixtures

Applying a mixture of fungicides can be useful to prevent the appearance of phytophthora in young plants. In addition, it can also eliminate the fungus in the early stages of the disease. 

Remove infected specimens

Once the disease has spread too much, it is almost impossible to eliminate it. If you have a much damaged specimen, it is best to remove it so that it doesn’t infect others nearby. 

Did you find these tips helpful? Would you add any more? Tell us in the comments. 


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