|Du Toit, L.j.|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2008
Publication Date: 1/4/2009
Citation: Bull, C.T., Du Toit, L. 2009. First Report of Bacterial Blight on Conventionally and Organically Grown Arugula in Nevada Caused by Pseudomonas syringae pv. alisalensis. Plant Disease 93:109. Interpretive Summary: Arugula production in Nevada provides significant supplies of this healthy leafy green to US markets, supplementing the California supply. Plant pathogens can limit the supply of this and other crucifers to consumers, as well as the profits of producers. The first step in reducing the impact of emerging plant diseases on crops is to identify the pathogen causing the disease. In this study, the bacterial pathogen identified as causing a leaf spot on organic and conventional arugula crops in Nevada had never previously been reported in Nevada. The arugula disease is caused by the same pathogen that causes bacterial blight on crucifers in CA and NJ, thus expanding the known geographic range of the pathogen. This information, coupled with previous research on management of the pathogen in vegetable crops, can be used by producers to make crop production choices that reduce spread of the pathogen from one susceptible crop to another.
Technical Abstract: A novel bacterial leaf spot was detected in commercial organic and conventional plantings of the arugula (Eruca vesicaria spp. sativa) cv. My Way in 2007. Koch’s postulates were completed and etiology of the pathogen was determined. Physiological and molecular characterization showed that the pathogen was Pseudomonas syringae pv. alisalensis. This is the first report of P. syringae pv. alisalensis causing a disease on commercially grown arugula in Nevada. This research expands the known geographic range of this pathogen to three US states, i.e., CA, NJ, and NV.