The relation between the contamination of flax seed with Polyspora Lini Laff. and Colletotrichum linicola Pethybr. & Laff. and the incidence of disease in the crop

Using naturally contaminated seed it is shown that the incidence of the seedling, stem-break and browning phases of attack by Polyspora Lini Laff. in flax crops is related to the contamination of the seed with the parasite, the relationship being closer at low or moderate than at high levels of seed contamination. Heavy attacks of the disease did not occur when the number of contaminated seeds was less than 5%. A similar relationship was found to exist between the contamination of seed with Colletotrichum linicola Pethybr. & Laff. and the incidence of seedling blight in the crops.