|Matheron, Michael - UNIV.ARIZONA,COOP.EXT.|
|Tickes, Barry - UNIV.ARIZONA,COOP.EXT.|
|Platts, Belinda - DOLE FRESH VEG.,SALINAS|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 3, 2003
Publication Date: August 20, 2003
Citation: McCreight, J.D., Matheron, M., Tickes, B., Platts, B. Occurrence of fusarium root rot race 1 on lettuce in Yuma Valley, Arizona. HortScience. 2003. v. 38:Abstract p. 664. Technical Abstract: Fusarium root rot of lettuce, incited by Fusarium oxysporum f.sp. lactucae, was first observed in Japan in 1955. It affected commercial U.S. lettuce production in 1990 in the San Joaquin Valley of California near Huron, but did not become a serious problem in the U.S. until 2001 when it reappeared in Huron and appeared in the Yuma, Arizona lettuce production area. It was found in the California coastal lettuce district of Pajaro Valley in 2002. Occurrences of two new physiological races of the pathogen in Japan were reported in 2001 and 2003 based on the reactions of three differential lettuce cultigens. Two California isolates were reported to be race 1. Results from naturally-infected field tests in Yuma, and artificially-inoculated greenhouse tests with a Yuma isolate indicate that the population of F. O. F.sp. lactucae present in Yuma is race 1. 'Costa Rica No. 4' (resistant to race 1, and susceptible to races 2 and 3) was resistant. 'Banchu Red Fire' (susceptible to races 1 and 3, and resistant to race 2), which was not included in the field tests, was susceptible in the greenhouse. 'Patriot' (susceptible to races 1, 2 and 3) was susceptible. Consistent with previous results from Japan, 'Salinas 88' was resistant.