Pasmo disease of flax

Pasmo disease is a significant fungal infection affecting flax crops, caused by the pathogen Boeremia linicola. This disease is known for its ability to cause severe damage to stems, leaves, and seed bolls, ultimately impacting both the fiber yield and the quality of linseed produced by the farm.

The disease primarily attacks commercial flax varieties. Typical symptoms involve the appearance of brown, circular, or irregular lesions on the stems and leaves. As the infection progresses, these spots often merge, leading to characteristic banding patterns on the stem that cause it to weaken and prematurely lodge or die before full maturity.

Environmental conditions play a crucial role in the development of Boeremia linicola. The fungus thrives in warm, humid weather, and rain splashes are the primary mechanism for dispersing spores from the soil and crop debris onto healthy plant tissues. High plant density can also exacerbate the spread by creating a favorable microclimate for the pathogen.

The economic impact of Pasmo is substantial, as it negatively affects the mechanical properties of the fiber and significantly reduces the weight and oil content of the seeds. In severe cases, the infection leads to uneven ripening and harvesting difficulties, resulting in major financial losses for producers across infested regions.

Effective management strategies against Pasmo include:

• Selection of disease-free, certified seeds for planting.
• Treatment of seeds with appropriate fungicides before sowing.
• Implementation of crop rotation cycles, avoiding flax for at least 4 years.
• Deep tillage to bury crop residues that harbor the pathogen.
• Application of foliar fungicides during the early stages of infection to suppress further development.