Jasmine anthracnose

Jasmine anthracnose is a fungal disease caused by the pathogen Colletotrichum jasminigenum. It is a highly specific fungus that targets members of the Jasminum genus, causing significant damage to the plant’s health and reducing its aesthetic value in garden and landscape settings.

The host range is limited to jasmine species, particularly those grown in high-humidity environments. The pathogen primarily affects foliage, petiole tissue, and young stems, disrupting the plant's ability to photosynthesize and transport nutrients efficiently.

Symptoms typically manifest as necrotic spots on leaves, which begin as small brown lesions and expand into larger, darker patches often surrounded by a chlorotic halo. In the center of these lesions, the fungus produces acervuli, which appear as tiny, dark, raised specks containing spores, easily observable during wet or humid weather conditions.

The development of Colletotrichum jasminigenum is heavily dependent on moisture. Water splash from rain or irrigation systems acts as the primary vector for spore dispersal. Temperatures ranging between 20°C and 25°C are optimal for the rapid germination and colonization of host tissues by the fungal hyphae.

The severity of the disease is high, as it can cause complete defoliation and dieback of the stems if left untreated. Prevention includes ensuring proper spacing between plants to maximize airflow, avoiding overhead irrigation to keep leaves dry, and removing infected plant parts immediately. Chemical control involves the application of appropriate fungicides, such as those containing copper or systemic agents, to manage outbreaks during the growing season.