Eryngium anthracnose fungus

Colletotrichum eryngiicola is a pathogenic fungus recognized as the causative agent of anthracnose in various species of Eryngium (sea holly). This fungal pathogen is known to specifically target the foliage and stems of these plants, compromising their health and significant ornamental value in landscapes and gardens.

The primary host range includes ornamental Eryngium species. When infection occurs, it can quickly weaken the plant structure, leading to premature senescence of leaves and affecting the overall vigor of the plant. It is considered a significant challenge for nurseries specializing in perennial ornamental plants.

Symptoms typically manifest as distinct necrotic lesions on leaves, often surrounded by dark or chlorotic margins. Under high humidity, the fungus produces acervuli within these spots, appearing as small, raised, pale or pinkish masses of spores. Over time, these lesions may coalesce, leading to extensive tissue death.

Environmental conditions play a critical role in the development and spread of the disease. High relative humidity, persistent leaf wetness, and moderate temperatures create an optimal environment for conidia germination and colonization. Wind-borne spores and water splashes are the primary vectors for local dispersal within a garden setting.

Management strategies involve a combination of sanitation and chemical interventions. It is essential to remove and destroy infected plant debris at the end of the season to reduce the inoculum level in the soil. Proper spacing to ensure adequate air circulation and avoiding overhead irrigation can significantly reduce infection risk. If the disease persists, application of systemic fungicides, particularly those containing strobilurins or triazoles, serves as an effective control measure for ornamental crops.