Aldonata leaf spot

Aldonata leaf spot (caused by the ascomycete Aldonata) is a specific fungal disease that primarily affects ornamental and certain vegetable crops. The disease belongs to the leaf spot group, characterized by the progressive necrosis of leaf tissue and the disruption of photosynthetic processes in the infected plant.

The primary pathogen is a highly specialized fungus that survives in the soil and on plant debris as mycelium or conidia. The disease is classified as an infectious spotting type, where spores are actively dispersed by wind, raindrops, and gardening tools during routine maintenance.

External symptoms of the disease appear as circular or irregular spots that are initially yellowish, eventually turning brown with a distinct dark border. In the center of the lesions, small black dots called pycnidia can often be seen, which contain the maturing spores of the pathogen.

The development of the disease is favored by high humidity (over 80%) and moderate temperatures ranging from +18 to +24 degrees Celsius. Densely planted areas and lack of ventilation in greenhouses create an ideal microenvironment for the rapid spread of the infection during the growing season.

The harm caused by the disease includes premature leaf drop, which significantly weakens the plant, reduces its aesthetic value, and leads to yield losses. Effective control measures include:

• Regular sanitation of the site to remove infected plant debris.
• Maintaining optimal plant spacing to improve air circulation.
• Application of broad-spectrum fungicides upon the first signs of infection.
• Watering exclusively at the root zone, avoiding contact with the leaf surface.