Main symptoms

Various alterations are attributed to it on melon:

- seedlings and black and depressed cankers appearing under the cotyledons at the time of emergence, root and crown rots on young seedlings in the nursery or after planting  ;

- chancery changes on the neck and the stem (figures 1 to 5). These are often dark green and moist at the start of the attack and can measure between 5 and 15 centimeters. Amber gummy droplets can appear on the surface, darkening as they oxidize (Figures 6 and 7). Subsequently, these lesions dry out, become cured, take on a brownish tint, and are sometimes strewn with a multitude of black microsclerotia  (50 to 200 µm) (figures 8 and 9) and pycnidia. Note that the lesions on the stem are reminiscent of those caused by Didymella bryoniae ;

- a reduction in the size of the root system, a brownish rot of the cortex of the roots and a degradation of the lower part of the stem in the most extreme situations;

- yellowing, wilting and drying out of the lower leaves located near the crown, resulting from lesions on stems and roots.

On fruits rather ripe and in contact with the soil, it causes moist, brown lesions covered with numerous black microsclerotia. The flesh takes on a pink to reddish tint. The seeds can be infected.

In addition, the symptoms often appear just before harvest.