What Diseases Do Avocado Trees Get?

Fresh Avocados on a tree

Table of Contents

Avocados are gaining popularity for their nutritious value, and it feels bad to see the trees wilting and the fruits falling prematurely. 

People have embraced growing avocado trees, and you will love growing one in your compound. However, the trees are exposed to various diseases that can affect their growth and productivity.

Some diseases affect specific species, while others attack all avocado trees and lead to fruit shedding.

Let’s check some of the common diseases that can affect your avocado tree. Stick on.

1. Phytophthora Root Rot

Root rot is common in almost all species of avocado trees, and it’s mostly caused by the soil fungus Phytophthora cinnamomi.

The earlier you control this disease, the less harm it will be to your precious plant. When the roots rot, the performance of the root system will be highly affected and can cause the death of your plant.

You will notice yellow leaves, low fruit yield black lesions on the roots, and premature leaf drops on your avocado tree. To minimize this fungus, plant your avocado tree in properly draining soil.

2. Avocado Black Streak

Avocado black streak is a dangerous disease that killed three of my young avocado trees within a short time. The disease has short- and long-term effects on your avocado tree.

First, your plant leaves will start turning brown and yellow with reduced fruit production, or it can lead to smaller and less tasty avocados. Sadly, the cause of avocado black streak remains unknown, making its prevention harder.

One distinct characteristic that my avocado plant showed in its later stage is the development of sores and cankers on the trunk branches and the wooden parts, and they would often kill new fruits as soon as they grow.

The best you can do to protect your plant from the disease is carefully water and keep healthy soil around the tree for longer life and production.

3. Armillaria Root Rot

The soil-borne fungus causes trunk and root rot in your avocado tree, and it establishes fully on the root crown before you start seeing a sign on other parts of the plant. Young plants are overwhelmed by the disease shortly after infection and die prematurely.

The first symptom away from the roots is downward hanging foliage and wilting. The tree leaves also turn yellow and die back on the upper limbs.

If it’s during the winter season, small mushrooms may start growing at the base of the infected plant. If you suspect your tree has the infection, cut the bark off the crown and base for diagnosis.

4. Dothiorella Canker

Dothiorella canker is another fungal disease that will hit your flourishing avocado plant. The cankers start developing on the trunk and then to the primary branches.

A white powder starts forming at the infected area, causing the trunk’s bark to peel and separate from the tree, and if the cancers proceed, your tree will look dead.

The good news is that your tree can recover and produce the highest avocado fruits with the right treatment. Keep pruning dead limbs, practice good sanitation, and consider using rootstock cultivars to resist the disease.

5. Verticillium Wilt

The disease turns the leaves brown where they die but will remain on the tree for months before falling. You can see the brown streaks in the xylem or when you remove the root’s bark.

Additionally, the tree will develop new shoots shortly after wilting, and the tree will recover fully with the proper care.

There’s no specific method of treating the infected trees since some recover on themselves, and after the dieback, new growth begins, and you only need to prune the dead branches. Even with complete recovery, don’t use parts of the infected tree as seed or bud wood.

6. Anthracnose

The fungus infection affects the avocado fruit and becomes a rot that remains latent until the fruit ripens. It’s not easy to separate an infected fruit when packaging, or by looking at it, you will see the problem when preparing it for consumption.

It affects almost all varieties, including Hass, whose hard skin hides the symptoms, making them undetectable until you cut the fruit. You can manage the disease with regular orchard sprays after the fruit set.

7. Algal Leaf Spot

Have you noticed red and yellow spots with irregular shapes on your plant’s leaves? You realize when you scratch the spot, a gray crust forms. It could be that the viral algal spot has gotten to your plant.

Though the infection might be harmless, it makes your plant undesirable. To manage the disease, ensure that your trees are properly pruned, plus remember to treat the infested ones with copper fungicides.

Final Thoughts

The above post will help you greatly identify diseases affecting your avocado tree. If you notice any of the above symptoms, go ahead with a proper diagnosis. Good farm practices like proper pruning and wide spacing will keep away diseases.

Remember to apply the right fungicides to your plants. A regular walk on your farm will help you notice any undesirable characteristics of your avocado tree and fruits.

More Of The Same Category​

Willow Dunham

Willow Dunham

Hi, my name is Willow Dunham, and I'm an avocado tree grower. I live in Florida with my girlfriend, Jane, and we have a big yard with 5 avocado trees. Avocado has always been one of my favorite foods. I love the taste and how versatile it is.

About Me

Recent Posts

Growing AVOCADO Tree Time Lapse