The low temperature optimum allows buildup on fall planted wheat. Difference in the genetics of southern and northern winter wheats may be important to interrupting buildup of virulen t races. South American germplasm is the primary source of resistance genes. Spring wheat has better resistance than w inter wheat. Winter wheat in the Northern Plains, however, may escape leaf rust because of early development and harvest.
Crown rust is a serious problem in oats.
Buckthorn acts as an overwintering sustrate for the pathogen and therefore provides local inoculum sources for local infection foci to become established very early in the growing season. The overwintering host also provides the link in the life cycle of the pathogen for sexual reproduction and the rapid recomination of virulence genes to generate new pathogenic races. Return to Outline Stripe Rust Stripe Rust is also called Yellow Rust. It is generally restricted to cooler climates and higher elevations. It is not a problem in the Central or Northern Plains states, but is a major dise ase of wheat in the Pacific Northwest.