ARS | Publication request: Experimental Sugar Beet Cultivars Evaluated for Resistance Bacterial Root Rot in Idaho, 2008

Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 17, 2009
Publication Date: March 26, 2010
Citation: Strausbaugh, C.A., Eujayl, I.A., Foote, P. 2010. Experimental Sugar Beet Cultivars Evaluated for Resistance Bacterial Root Rot in Idaho, 2008. Plant Disease Management Reports. 4:FC011.

Interpretive Summary: Bacterial root rot in sugar beet is a disease problem that was recently described in the Intermountain West region of the United States. This bacterial root rot problem is frequently found in association with Rhizoctonia root rot in the field and leads to losses in the field, storage piles, and factories. At this time, there are no established management options for this disease problem. Host resistance is usually the most economical and environmentally friendly means to control disease problems, so a study was conducted to identifying the level of resistance to bacterial root rot in experimental sugar beet germplasm. These data should provide a starting point in the search for resistance to bacterial root rot in sugar beet. Cultivars with improved resistance should lead to less sucrose loss in the field and storage piles, and improve factory efficiency.

Technical Abstract: Bacterial root rot of sugar beet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, a study was conducted to identify resistance in experimental sugar beet germplasm. In 2008, 36 experimental sugar beet cultivars were grown, hand dug, and tested in a Petri dish laboratory assay after being stored in a cold room for 98 days. Root slices were inoculated with L. mesenteroides, incubated at 30°C, and the diameter of the rotted area was measured after 72, 96, and 120 hr. The cultivars were tested in a randomized complete block design with four replications. Root rot after 120 hr in the experimental cultivars ranged from 3 to 18 mm, while the least significant difference was 6 mm. These data should provide a starting point in the search to identify resistance to L. mesenteroides in sugar beet. Given the range of responses, improving sugar beet cultivars for resistance to bacterial root rot should be a possibility.