Observations on wilt disease of flax

Abstract

Summary The occurrence and symptoms of wilt disease of flax caused by Fusarium Lini in experimental plots at Aberystwyth in 1942–5 are described. The source of infection was the Canadian seed of the variety Redwing. Isolations of the fungus were made from seeds, stems and roots of diseased plants. Pathogenicity experiments using sterilized soil inoculated with these isolates showed that the fungus was a virulent parasite. La Plata was very susceptible both in pathogenicity experiments and in the field. Redwing was fairly susceptible and Bison, although it suffered severely from the disease, was more resistant. It was confirmed that flax plants can be attacked at any stage of development and that the incidence of wilt disease is closely correlated with suitable soil temperatures. When the plants were attacked in Aberystwyth, the disease was usually associated with infection by Polyspora Lini . Seed dressings give considerable protection against infection during the early stages of germination, but are not so effective against attack on older plants. They may be a useful supplement to the more promising method of control, the breeding of resistant varieties of flax.