Technical Abstract: Bacterial root rot caused by Leuconostoc mesenteroides subsp. dextranicum is an important problem in sugar beets because of issues it causes in the field, storage, and factories. Thirty-three transgenic (roundup ready) sugar beet cultivars were grown in a commercial irrigated field. Four roots from each cultivar were hand harvested and topped on 1 Oct 07 and stored at 3°C till assayed on 3 Feb 08. Roots were surface sterilized and cross sectioned. The slice from the middle of the root was inoculated with a tooth pick that had been dipped in a 48 hr old culture of L. mesenteroides. The inoculated slices were placed in a Petri dish, arranged in a randomized complete block design and incubated at 30°C. The rot diameter was recorded at 72 and 96 hr. After 96 hr, rot ranged from a high of 27 mm with cultivar C10 to a low of 9 mm with cultivar C4. This range of responses in the cultivars for bacterial rot indicates it may be possible to improve resistance to L. mesenteroides in sugar beet cultivars through breeding efforts.