Trichoderma hamatum

Trichoderma hamatum is a soil-borne fungus that typically functions as a beneficial antagonist but can act as a pathogen under specific agricultural conditions. While widely recognized in biological control, certain strains or environmental stresses can cause this fungus to shift its behavior, leading to plant tissue damage and the development of various rot diseases in weakened crops.

The disease primarily impacts greenhouse vegetables, ornamental plants, and young seedlings. It tends to target the root system and the crown of the plant, which are the most vulnerable parts during the early stages of growth. If the plant's natural defense systems are compromised by stress, this fungus can colonize tissues rapidly.

Symptoms of the infection include water-soaked lesions on roots and stems, which progressively darken and become necrotic. As the infection advances, the plant may wilt, and the base of the stem can show significant softening. Under high humidity, a white to green mycelial growth may appear on the decaying plant parts, indicating the presence of fungal spores.

The development and spread of Trichoderma hamatum are favored by high soil moisture levels, inadequate drainage, and poor ventilation within greenhouses. The fungus thrives in soils rich in organic matter, where it survives as a saprophyte before opportunistically attacking the host plant when stress factors such as waterlogging or root damage occur.

Effective management requires a combination of strict sanitation and proper environmental control. Growers should focus on sterilizing growing media, optimizing irrigation schedules to prevent moisture stress, and improving airflow around seedlings. In cases of severe outbreaks, targeted fungicide applications and soil amendments can help suppress fungal growth and protect the crop.