Fungal and bacterial species associated with storage diseases in sugarbeets from the Red River Valley of Minnesota and North Dakota

Authors: BILL, MALICK - North Dakota State University; BRUNI, GILLIAN - US Department Of Agriculture (USDA); ADHIKARI, SHRADDHA - North Dakota State University; Fugate, Karen; QI, YUNCI - US Department Of Agriculture (USDA); KHAN, MOHAMED - North Dakota State University; LIU, ZHAOHUI - North Dakota State University; Kandel, Shyam

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sugarbeet is an important source of sucrose used for natural sweetening in the U.S. and beyond. Sugarbeet roots harvested in the Red River Valley (RRV) of Minnesota and North Dakota in the U.S. require storage for up to seven months under ambient weather conditions. Preserving sucrose in sugarbeet roots during storage is challenging due to storage diseases which reduce sucrose content and processing quality of the roots. Knowledge of the pathogens responsible for this sucrose loss is limited but crucial for devising management strategies. This study was conducted to identify storage pathogens infecting sugarbeet roots stored in non-ventilated piles in MN and ND during the 2021/22 and 2022/23 processing campaigns. Penicillium spp., Geotrichum candidum, Mucor spp., Botrytis cinerea, Pichia spp., Candida spp., Hanseniaspora valbyensis, and Kurtzmaniella quercitrusa were common fungal species and Leuconostoc mesenteroides and Gluconobacter cerinus were common bacterial species associated with storage diseases of sugarbeet. This study identified major postharvest storage pathogens of sugarbeet roots in the RRV of MN and ND, which will be key information in developing effective management strategies to minimize postharvest sucrose losses during sugarbeet storage.

Technical Abstract: Sugarbeet is a major source of consumable sugar in domestic and industrial applications in the U.S. Sugarbeet roots are stored for up to seven months under ambient weather conditions. During this period, storage rots often develop reducing sucrose content and processing quality of the roots. Knowledge of the pathogens responsible for this sucrose loss is limited but crucial for devising management strategies. This study was conducted to identify storage pathogens infecting sugarbeet roots in the Red River Valley (RRV) of Minnesota (MN) and North Dakota (ND) and characterize their prevalence and geographic distribution. In the first year of the study, over 50 roots exhibiting storage rot were collected from an outdoor non-ventilated pile (ONVP) in MN. In the successive year, 150 storage rot symptomatic roots were collected from five geographically distinct ONVPs with three located in MN and two located in ND. Penicillium spp., Geotrichum candidum, and Mucor spp., were common filamentous fungal species identified, while Pichia membranifaciens was the dominant yeast identified in both years of the study. Leuconostoc mesenteroides and Gluconobacter cerinus were the common bacterial isolates in both surveys. Most of bacterial isolates (2022/23 survey) obtained from ONVP-4 (ND) (63%) and ONVP-5 (ND) (99%) were identified as L. mesenteroides. This study identified major postharvest pathogens of sugarbeet roots in the RRV of MN and ND, which is pivotal for implementing management strategies to minimize postharvest sucrose losses during sugarbeet storage.