|Du Toit, L - WASHINGTON STATE UNIV|
|Fichtner, S - COLORADO STATE UNIV|
|Mohan, S - UNIVERSITY OF IDAHO|
|Pappu, H - WASHINGTON STATE UNIV|
|Schwartz, H - COLORADO STATE UNIV|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 26, 2006
Publication Date: December 31, 2006
Citation: Gent, D.H., Du Toit, L.J., Fichtner, S.F., Mohan, S.K., Pappu, H.R., Schwartz, H.F. 2006. Iris yellow spot virus: An emerging threat to onion bulb and seed production. Plant Disease. Interpretive Summary: Iris yellow spot, caused by Iris yellow spot virus, is an emerging disease of onion in the U.S. and world. This manuscript presents a summary of the history of iris yellow spot research, current knowledge of disease etiology and epidemiology, and advances in integrated management of iris yellow spot. Little is known about the disease cycle and epidemiology of iris yellow spot. Recent research has identified new elements of disease biology and epidemiology, and suggests the disease may be managed successfully by integrating biological, cultural, and chemical control strategies.
Technical Abstract: Iris yellow spot, caused by Iris yellow spot virus, is an emerging disease of onion in the U.S. and world. The disease has become pandemic in onion in the past decade, and new hosts of the virus continue to be reported. Yield losses vary depending on cultivar susceptibility and grower cultural practices, and may range from undetectable to 100% in onion seed crops. Little is known about disease epidemiology, but recent research has identified important inoculum sources of the pathogen, non-chemical practices that reduce the incidence of disease, and cultivars with moderate levels of resistance to iris yellow spot. A summary of current knowledge on disease etiology, epidemiology, and management is presented, as are prospects for future research. Successful management of iris yellow spot requires an integration of biological, cultural, and chemical control strategies to reduce disease to an economically-acceptable level.