Stem Rust in Nebraska. Part I. General Survey of Sources. Part II. Identification of the Physiologic Forms of Puccinia graminis from Various Sources

Part I: Since the inception of the barberry eradication campaign in 1918 in Nebraska, the question has continually been asked, Will the eradication of the barberry in the state eliminate or materially reduce stem rust? In order that an answer might be obtained, an investigation to determine the sources of primary infection of stem rust on cereals was inaugurated in the spring of 1921. Although these studies have been carried on for 6 years, no definite statement regarding the relative importance of the primary sources and the amount of stem rust prevalent in the state from season to season originating from these sources can be made. However, a general idea of the rust situation which existed during these years in Nebraska can be deduced from the results herewith presented. Part II: In an effort to ascertain more completely the primary sources of stem rust, the identification of the physiologic forms of Puccinia graminis and the physiologic forms of P. graminis tritici from numerous collections of rust material from near barberries, and throughout the state was begun in 1924 and carried on for three seasons