Dryland root rot of wheat and barley in South Australia is a syndrome from which the associated fungiFusarium equiseti, F. acuminatum, F. oxysporumandBipolaris sorokinianawere isolated consistently.Fusariuminfections were concentrated on the subcrown internodes, crown roots and culm bases, and occurred with equal frequency on wheat and barley.Bipolarisinfections were more numerous on barley than on wheat, and were concentrated on culm bases and subcrown internodes. Recoveries of each of the four fungi showed a pattern of infection that was neither randomly nor evenly distributed. Each fungus had preferences for certain sites which resulted in a stratified distribution over the roots and crown. When two barley cultivars were compared, the patterns of infection were different; the subcrown internode was attacked more severely, and there was a substantial increase in the amount of infection by all four fungi on one of the cultivars. Pathogenicity tests on barley and oats showed that all four species of fungi were capable of causing damage to roots, but there were differences between isolates of each fungus and differences in their ability to damage barley and oats.
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