False loose smut

False loose smut is a fungal disease that affects cereal crops, particularly barley and wheat. It is caused by the fungus Ustilago nigra. The disease is characterized by the replacement of the grain with masses of dark, powdery spores, which are released during the harvesting process, leading to significant yield losses.

Symptoms

The primary symptom of false loose smut is the presence of black, powdery spore masses in place of the normal grain. These spore masses are typically visible at the time of heading and flowering of the crop. Infected plants may also exhibit stunted growth and reduced vigor.

Life Cycle

The life cycle of Ustilago nigra begins with the germination of teliospores, which produce basidiospores. These basidiospores infect the host plant during the flowering stage. The fungus then grows systemically within the plant, eventually replacing the developing grain with smut spores. These spores are released during harvest, contaminating the soil and nearby plants, thus continuing the cycle.

Management

Effective management of false loose smut involves several strategies:

• Seed Treatment: Treating seeds with fungicides can help prevent the initial infection.
• Resistant Varieties: Planting resistant varieties of barley and wheat can reduce the incidence of the disease.
• Crop Rotation: Rotating crops with non-host species can help break the life cycle of the fungus.
• Sanitation: Removing and destroying infected plant debris can reduce the source of inoculum.

Economic Impact

False loose smut can cause significant economic losses due to reduced yield and quality of the grain. The presence of smut spores can also affect the marketability of the crop.

Related Pages

• Barley
• Wheat
• Fungal diseases of plants
• Crop rotation
• Fungicide

See Also

• Loose smut
• Covered smut
• Plant pathology