Chaetomium globosum

Chaetomium globosum is a filamentous fungus belonging to the Ascomycota division. While primarily known as a cellulolytic organism in nature, it is also a well-documented opportunistic plant pathogen. It is frequently associated with seed-borne diseases, causing significant deterioration of seeds and seedlings in various agricultural crops.

The host range of this fungus is extensive, including cereals, legumes, oilseeds, and vegetables. It is particularly problematic in grain storage, where it colonizes seeds that have been exposed to high humidity. The fungus causes "seed mold," which impairs the physiological quality of the seed and leads to poor germination and establishment of the crop in the field.

Symptoms of Chaetomium globosum infection typically appear as a dark, olivaceous-brown, or greyish-black powdery growth covering the surface of seeds or decaying plant tissue. Infected seedlings often show signs of necrosis, stunting, and rot, usually occurring in the radicle or the base of the stem, eventually leading to pre-emergence or post-emergence damping-off.

The development and spread of the fungus are highly dependent on environmental factors. It thrives in conditions of high humidity (relative humidity >80%) and temperatures between 20°C and 30°C. The spores are easily dispersed by wind, rain splash, and contaminated farm machinery, allowing the pathogen to persist in soil and crop debris for extended periods.

Integrated pest management strategies are crucial for controlling Chaetomium globosum:

• Treating seeds with effective broad-spectrum fungicides.
• Managing grain moisture levels below 14% to prevent storage decay.
• Improving field sanitation and removing infected plant residues.
• Practicing crop rotation to reduce inoculum build-up in the soil.
• Implementing good ventilation in greenhouses and storage facilities.