Fig diseases are ignored most of the time even though they are a serious problem. When I inspect other people’s figs, I find diseases more often than pests. They can be easily mistaken for pests attacking the tree because some of them have similar symptoms.
If you suspect pests might attack your tree, I’ve written an article about them as well.
What Is Attacking My Fig Tree? – Common Insect Pests on Fig Trees
Most common fig tree diseases:
- Fig rust (fungus)
- Anthracnose (fungus, several disease varieties)
- Leaf Blight (fungus, many disease varieties)
- Fig mosaic (virus, 12+ virus types)
Fig Rust
Fig rust is a fungus that causes leaves to die and fall off. Even though most people think fig rust doesn’t affect the fruit, it does. It causes fruit to be ripe prematurely.
It’s not particularly dangerous for a tree’s survival, but you can expect reduced yield and slow growth if it happens a few years in a row.
The best way to identify is by brown spots on the leaves. When affected by fig rust, the spots range from small to big. They can also appear on the fruit and might seem like something stung it at first.
How to Treat and Prevent Fig Rust?
Fig rust can be treated with fungicides containing copper sulfate and lime. This type of fungicide can be used once a week for most of the growing season, which lasts from April to November. However, it’s best not to use it past June because the fruit won’t be edible. Other fungicides are not as effective and not recommended for fig trees.
Fig rust appears in humid conditions during the growing season. Especially if the summer is rainy, keeping your fig dry will prevent fig rust. The best way to do that is by pruning unnecessary branches in the middle to improve airflow.
Anthracnose
Glomerella cingulata is the most common fungus that causes fig anthracnose. It attacks the fig tree’s leaves and fruit. Fruit that rots and falls off the tree prematurely, as well as immature fruit that shrivels and never falls from the tree, are all indications of fig anthracnose. Sunken, discolored patches will appear on the fruit. These patches will grow pink spores as the disease advances.
Anthracnose of figs generates a dark brown edge on the leaves, which surrounds dots that are somewhat depressed. These spread and mix over time, resulting in vast regions of brown on the leaves. The edges of the leaves develop a dry, brown border, and the leaves eventually fall off the tree.
How to Treat and Prevent Fig Anthracnose?
No chemical solution for fig anthracnose will successfully remove the illness while keeping the fruit edible. Some people claim that the fruit is fine to eat after using fungicides with copper, which effectively stops the spread. However, I would avoid poisoning myself with heavy metals.
Prevention and effective management best control the disease and prevent it from harming trees and crops.
I try to keep my fig trees well-maintained to be more resistant to diseases like anthracnose. These trees require full sun to partial shade, well-drained soil, and a warm environment to thrive and resist disease.
Fig trees can survive wet circumstances, although they are more susceptible to fungal infections. You should avoid watering from above, which isn’t recommended for fig trees anyway.
Despite your best efforts, fig anthracnose symptoms may appear on your tree. If this is the case, remove all afflicted branches and dispose of them properly. Keep the space under the tree clean and clear of debris, particularly the sick tree portions that have been clipped.
Thread Blight and Leaf Blight on Fig Trees
A blight is actually a group of fungal diseases, all causing yellow spots on leaves. The whole group of fungus causing this disease is very similar, in symptoms and spreading.
Most articles focus on only one fungus causing leaf blight, but that’s not ideal because there are tiny differences. It’s impossible to determine which fungus is affecting the tree in a good portion of blight cases. That’s why it’s better to discuss the whole fungus group at once.
Leaf blight is rarely fatal for the tree, but it can spread fast in the right conditions like other fungal diseases.
How to Treat and Prevent Blight on Fig Trees
Treatment includes copper and lime-based fungicides like previously mentioned fungal diseases. Copper fungicides were applied on figs in the past, but today there are stricter regulations on fruit quality. If you want to use them, I suggest precisely spraying the leaves and avoiding fruit, especially past June.
The best prevention method is to remove all the infected leaves. It’s almost impossible to get rid of leaf blight, but it’s possible to control it. Like other fungal diseases, it’s easiest to control in dry conditions with good airflow, which is a good reminder that trees need to be planted with enough room between them.
Fig Mosaic
MD (Fig Mosaic Disease) is a complex viral disease caused by 12 different viruses. Mosaic dots on leaves are a bright yellow color that contrasts with the regular green color of the foliage.
The yellow spots’ borders progressively fade from a bright yellow to the dark green of healthy tissue. The eriophyid mite (Aceria fici) and vegetative cuttings and grafting are virtually certainly how the fig tree virus enters the plant.
Later in the season, a rust-colored band appears along the mosaic spot’s perimeter, which is thought to be generated by epidermal or subepidermal cell death.
The appearance of fig mosaic lesions on fruit is similar, though not nearly as pronounced. Premature fruit drop or poor fruit yield are the most common symptoms of the fig tree virus in most varieties.
Black Mission fig trees are more severely damaged than Kadota and Calimyrna fig trees. Ficus palmata and trees bred from seedlings with Ficus palmata as the male parent are resistant to fig tree mosaic.
How to Treat and Prevent Fig Mosaic?
I did not find chemical controls to be successful in the treatment or eradication of fig mosaic disease.
Controlling fig mites may be your only option for fig mosaic disease treatment. Once the mites do the work for me, I apply measures against them. You can use several horticultural oils (crop oil, citrus oil, etc.) to control mite infiltration and, as a result, aid in the cessation of the disease.
The best prevention method is to choose trees that do not have mosaic symptoms. Before planting young seedlings in the field, carefully inspect them for mosaic signs. Planting fig cultivars grown from mosaic-infected trees is never a good idea.
Why is My Fig Sour? Fig Endosepsis and Other Causes
Fig fruit souring is the result of many different diseases, all of which have the same outcome. Many bacteria and fungi can cause these diseases. Most of the time, fig souring happens to only a few fruits on a tree and rarely causes major yield failure.
However, when it affects a big portion of yield, it can be a serious problem. I’ve even seen some people go so far as to destroy whole trees to prevent infection from spreading. In my opinion, that is not necessary, but it is effective.
These types of diseases are spread by insects that crawl inside ripe figs and die. Therefore, if many insects carry bacteria or fungi, the damage can be huge.
The fruit starts to go bad from the inside, turning into a brown rot. In my experience, it’s not easy to spot early. To prevent this, I regularly inspect fruit on my trees. If I find rotten figs, I remove them immediately.
Fig endosepsis and similar diseases are borderline impossible to treat once they affect most of the fruit on the tree. My only solution was to remove all the fruit from an infected tree. That way, I can at least stop it from spreading to other trees.
Luckily, it rarely goes this far, while some species seem resistant to disease spread.
Conclusion
These are the diseases I’ve had experience with. Unlike pests, they don’t always need to be treated. I believe chemical solutions are more harmful to the fruit than these diseases. Therefore, I choose to prevent and control these diseases instead of eradicating them.
Luckily for us, most diseases don’t cause too much harm even when left untreated. However, they can spread quickly and reduce fruit yield.