Reaction of spring barley cultivars grown in Finland to soil-borne infection by Bipolaris sorokiniana and to its toxic metabolites.
Soil-borne infection by B. sorokiniana (Cochliobolus sativus) caused foot and root rot in all cultivars studied, but significant differences were observed in cv. susceptibility and pathogenicity of isolates. Primary symptoms were seedling blight, later foot and root rot. Yield losses were 3-33% (av. 15%) and could occur without severe symptoms. Toxic metabolites produced by the fungus induced visible foot and root rot symptoms in all cultivars tested and caused leaf lesions in some. Variability in toxin production among isolates and in cv. reaction to toxins was demonstrated. The cultivars most susceptible to soil-borne infection were also the most affected by the toxins.