Pasmo

The causal agent of pasmo disease is fungus Septoria linicola (Speg.) Garassini.
Spores of this fungus are dispersed by rain, wind, dew, insects etc.
The fungus infects flax leaves, causing defoliation under severe epidemics. It also infects the pedicels, which are the tiny branches that carry the flax bolls. Infected pedicels are weak, so windy and rainy conditions result in boll-drop, causing serious yield loss.
The disease also infects the stems, causing alternating bands of brown infected tissue and green healthy tissue. The infected stems tend to lodge. Moist conditions in the lodged crop favour the further spread of pasmo as well as the growth of other fungal diseases, like alternaria and botrytis, which can result in a mouldy stand with greatly reduced seed yield and quality.