Evaluation of Cercospora leaf spot and postharvest rot pathogen impacts on sugar beet storage

Authors: HENDERSHOT, CARLY - Michigan State University; BLOOMINGDALE, CHRIS - Michigan State University; CORDER, HOLLY - Michigan State University; Goodwill, Tom; RUTH, SARAH - Michigan State University; PINCUMBE, CAMERON - Michigan State University; BEAUDRY, RANDY - Michigan State University; Hanson, Linda; WILBUR, JAIME - Michigan State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2022
Publication Date: 11/1/2022
Citation: Hendershot, C., Bloomingdale, C., Corder, H., Goodwill, T.R., Ruth, S., Pincumbe, C., Beaudry, R., Hanson, L.E., Wilbur, J.F. 2022. Evaluation of Cercospora leaf spot and postharvest rot pathogen impacts on sugar beet storage [abstrace]. Abstracts of Presentations at Plant Health 2022 112:S3.151. https://doi.org/10.1094/PHYTO-112-11-S3.1.
DOI: https://doi.org/10.1094/PHYTO-112-11-S3.1

Interpretive Summary:

Technical Abstract: In Michigan, sugar beets (Beta vulgaris) are stored for up to 200 days post-harvest. During storage, sugar content is reduced due to rot in addition to regular energy use from respiration. Cercospora leaf spot (CLS), the most damaging foliar disease of sugar beet, is further hypothesized to be a predisposing factor for storage losses. However, previous studies have presented conflicting evidence of this interaction and the effects of CLS remain unclear for specific storage pathogens. To investigate the impact of CLS on storage rot, post-harvest symptom development was evaluated in beets with relatively high or low in-season CLS severity. At three timepoints during storage, roots of each CLS level were inoculated with Fusarium graminearum, Botrytis cinerea, Penicillium vulpinum, or Geotrichum candidum and symptoms assessed after 7 days. For all pathogens tested, there were no significant differences between storage rot susceptibility in beets with high or low CLS levels in the field at any timepoint (P > 0.05), though lesion development varied among beet varieties. The effect of CLS on root respiration rate also was evaluated in beets with high and low CLS severities. Roots were stored in respirometry chambers, and respiration rate was measured monthly. No significant differences were observed in respiration rate of beets with high or low CLS levels (P > 0.05). Validation of the effects of CLS on rot development of inoculated beets will be completed. Delay or reduction in storage rot could prevent significant losses and improve yield and profit for sugar farmers.