Submitted to: Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/7/2011
Publication Date: 9/7/2011
Citation: Hanson, L.E., McGrath, J.M. 2011. Seedling damping-off in sugar beet in Michigan. International Institute for Beet Research Workshop Proceedings. Available: http://www.iirb.org/media/hanson_seedling_damping_off_joint_pests_diseases_seed_quality_2011.pdf
Technical Abstract: A number of pathogens can cause early season stand loss in sugar beet. In an ongoing survey, the most commonly identified damping-off pathogens were Rhizoctonia solani, Aphanomyces cochlioides, and Fusarium species. Pythium and Phoma also were isolated every year, but never as the sole or most common pathogen from any fields examined. Isolates of all of these pathogens caused disease when inoculated on sugar beets in the greenhouse. Other fungi, such as Alternaria, Mucor, and Rhizopus, were isolated occassionally from a small number of beets. These three fungi have been reported as potential weak pathogens and are being tested further. Rhizoctonia solani isolates included both AG-2-2 and AG-4, with AG-2-2 predominating, making up about 80% of the R. solani collected. Sugar beet with tolerance to the three major pathogens at the seedling stage has been identified and screening is ongoing to find additional tolerant USDA germplasm with tolerance damping-off from one or more of these pathogens.