It generally survives as mycelium or uredinia on volunteer wheat during the non-wheat growing season. Uredinospore can be spread by wind into disease-free areas. Sporulating uredinia are active in tropical and some subtropical areas throughout the winter. Occasional dormant mycelium may survive beneath the snow pack in more northern temperate regions. Urediniospores and aeciospores are wind borne.
Teliospores remain with the straw.
Stem rust is generally confined to Triticum species, although naturally infected plants of Secale cereale , Hordeum vulgaris , H . jubatum , H . Many genera of the tribe Hordeae are infected when artificially inoculated. Other formae specialis of P . Luig, N. H., 1985. Epidemiology in Australia and New Zealand.