Fig powdery mildew

The pathogen completes its life cycle by developing a superficial mycelium on the surface of leaves and producing conidia for asexual reproduction.

It forms specialized survival structures known as cleistothecia, which allow the fungus to overwinter in fallen leaves and plant debris.

The fungus feeds by inserting haustoria into the epidermal cells of the host, extracting nutrients directly from the fig tree's tissues.

This pathogen is host-specific and is primarily found on Ficus carica, spreading via wind-borne spores throughout the growing season.

The most visible sign of infection is a white, dusty, or floury fungal growth appearing primarily on the undersides of the leaves.

As the infection progresses, the spots may expand and cause the leaves to turn yellow or brown, leading to necrotic patches on the leaf tissue.

Severe infestations often result in leaf curling, premature drying, and significant leaf drop, which can leave the branches bare.

Under magnification, tiny, black, dot-like fruiting bodies (cleistothecia) can be observed scattered within the white mycelial mats.

• powdery white growth on the lower leaf surface;
• yellowing and chlorosis of the foliage;
• leaf distortion and curling;
• premature shedding of leaves;
• stunted shoot growth.

Phylactinia caricae thrives in moderate temperatures and high humidity, which are common in many subtropical growing regions.

Poor air circulation within the tree canopy provides a protected, humid microclimate that is ideal for the germination of fungal spores.

Fluctuations in temperature combined with nighttime dew create a perfect environment for the rapid colonization of new leaf tissues.

Dense, unpruned trees are significantly more susceptible to outbreaks because they trap moisture and limit sunlight penetration.

Succulent, fast-growing tissue caused by excessive nitrogen fertilization is more prone to rapid infection by the powdery mildew fungus.

The infection severely impacts the plant's ability to perform photosynthesis, leading to reduced energy reserves for the tree.

The lack of nutrients due to leaf damage causes poor fruit set, stunted fruit development, and decreased sugar accumulation in the figs.

Defoliation caused by the fungus weakens the tree, making it susceptible to cold stress during the winter and secondary pest attacks.

Long-term infestation leads to a decline in tree vigor, resulting in reduced yields and eventually killing the plant if left untreated.

The economic impact is substantial, as both the quality and the quantity of the fruit crop are negatively affected by the disease.

Proper pruning to open up the center of the tree canopy is essential to improve airflow and reduce humidity levels around the foliage.

Sanitation is a key preventive measure; all fallen leaves and infected debris should be removed and destroyed to reduce inoculum levels.

Preventative applications of sulfur-based fungicides or appropriate systemic treatments are highly effective when applied at the first sign of symptoms.

Maintaining a balanced nutritional program, particularly adequate potassium and phosphorus, helps improve the tree's natural resistance.

Monitoring the orchard during warm, humid periods allows for early intervention, which prevents the disease from reaching epidemic proportions.