Description of the fungus
The fungus responsible for anthracnose is an ascomycete which has two forms of reproduction:
- a sexual or teleomorphic form in the form of brownish stromas more or less immersed in the plant tissues. Within these stromas , one can observe several cavities (or locules) containing asci globular to ovoid, even ellipsoid , measuring 80-100 x 11-23 µm. They enclose eight ascospores brown to black , measuring between 29-35 x 4.5-7 µm and showing 3 partitions.
- an asexual or anamorphic form ( Sphaceloma ampelinum ) causing superficial to subcuticular acervuli on the leaves. On these acervuli, as on the stromas, are made up of numerous conidiophores which form hyaline and ellipsoid conidia measuring 3-7.5 x 2-8 µm.