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ARS Home » Midwest Area » East Lansing, Michigan » Sugarbeet and Bean Research » Research » Publications at this Location » Publication #392595

Research Project: Genetic Characterization for Sugar Beet Improvement

Location: Sugarbeet and Bean Research

Title: Diagnostic guide for Alternaria leaf spot on sugar beet, red beet, and chard

item CRIZON CORTES, SARAH - Universidad De Los Andes
item Hanson, Linda
item MILES, LAURA - Michigan State University
item WILBUR, JAIME - Michigan State University
item Naegele, Rachel

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/23/2022
Publication Date: 12/14/2022
Citation: Crizon Cortes, S., Hanson, L.E., Miles, L., Wilbur, J., Naegele, R.P. 2022. Diagnostic guide for Alternaria leaf spot on sugar beet, red beet, and chard. Plant Health Progress. 23(4):497-506.

Interpretive Summary: Alternaria leaf spot on sugarbeet is relatively common and has been a consistently economic disease for sugarbeet growers since 2015. Early detection is essential, and this diagnostic guide details signs and symptoms as well as provides easy to follow flow charts for determining the Alternaria species, if any, recovered from the leaf spot. This guide will be used by PCAs, extension agents, diagnostic clinics and, to some extent, growers.

Technical Abstract: Alternaria leaf spot, caused by Alternaria spp., is a common foliar disease of sugar beet and other Beta vulgaris crop types. Known to be present in the United States since at least the 1950s, this disease has been found in all major sugar beet growing regions of the United States as well being reported as present everywhere beets are grown. Alternaria leaf spot symptoms are similar to several other common foliar diseases of beets including Cercospora leaf spot and the early stages of Phoma leaf spot. Symptoms and signs of this disease in the field do not provide enough information to help distinguish between diseases unless the viewer is readily familiar with the pathogen, especially when viewed with the unaided eye. Alternaria cultures can be identified to species using colony and conidial morphology on select culture media or using molecular markers. While not as common as Cercospora leaf spot, Alternaria leaf spot can result in significant reductions in yield and quality when not managed.