Diseases

Tomato Leaf Mold

Solanum lycopersicum L.

An economically significant disease of tomatoes caused by the fungus Passalora fulva, characterized by the appearance of chlorotic spots on leaves followed by the formation of an olive-brown velvety mold on their undersides.

In the reference 1 086 varieties crop Tomato, where this is mentioned in the description.

The causal agent of the disease is the monophagous fungus Passalora fulva. The pathogen possesses high genetic variability, which allows it to adapt to cultivar resistance genes; consequently, the classification of races includes numerous groups, and many previously effective resistance genes have lost their significance.

Symptoms appear on the leaves as ill-defined chlorotic spots, beneath which a characteristic velvety mold forms on the underside of the leaf blade, eventually turning olive or brown in color. As the disease progresses, the tissues become necrotic, leading to wilting, curling, and premature shedding of the leaves.

In tomato breeding, more than 20 resistance genes to the pathogen are known, designated as Cf. In professional cultivar descriptions, resistance is marked with codes Ff, Pf, or C, often with appended numbers indicating resistance to specific fungal races; however, such protection is not absolute and may be overcome by new aggressive strains.

General information about the subject — on the page Leaf mold (brown leaf spot).

Sources8

Varieties of Tomato mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.