Submitted to: American Seed Trade Association Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/10/2003
Publication Date: 1/15/2004
Citation: Hartman, G.L., Miles, M.R., Frederick, R.D. 2004. Epidemiology and spread of soybean rust. American Seed Trade Association Conference Proceedings; 2004
Technical Abstract: Soybean rust is caused by two fungal species, Phakopsora meibomiae and P. pachyrhizi. The Asian soybean rust pathogen is known as P. pachyrhizi and is the species of greater concern since it is the more aggressive species and it has been identified in new geographical locations beyond Asia. The first report of soybean rust in the literature was from Japan in 1902. In tropical Southeast Asia, the disease is endemic and occurs throughout most of the year. On the African continent, the distribution of soybean rust was not well known before 1996, but since then a more expanded view of soybean rust in Africa has been reported indicating that it was found in 1996 in Uganda, Kenya, and Rwanda, in Zimbabwe and Zambia during 1998, Nigeria in 1999, Mozambique in 2000, and South Africa in 2001. Soybean rust was first reported in the U.S. in Hawaii in 1994, where the pathogen was found on soybean on Oahu, Kakaha, Kauai, and Hilo islands. The presence of the disease was confirmed in the 2001-2002 season in both Paraguay and Brazil, with reports of severe disease in some fields. Argentina confirmed the occurrence of soybean rust in early 2002. One of the possible pathways that the pathogen may reach the soybean growing areas in North America is through the land bridge that extends from South America through Central America and into the southern U.S. Another possible spore pathway may occur on winds from Africa to the Caribbean or to the U.S. mainland. Also, the pathogen may enter the U.S. mainland through debris in seed produced in South America or as a contaminant on clothes, boots, etc., of people moving from infested regions back to the U.S.