Rhizomania caused by Beet necrotic yellow vein virus (BNYVV) and storage losses are serious sugar beet production problems. To identify sugar beet germplasm lines with resistance to BNYVV and storage rots, 30 lines from the USDA-ARS Ft. Collins sugar beet program and four check cultivars were screened. The lines were grown in a sugar beet field infested with BNYVV during the 2019 growing season in a randomized complete block design with 6 replications. At harvest on 15 October 2019, roots were dug and evaluated for rhizomania symptoms and then placed in an indoor commercial sugar beet storage building. After 129 days in storage, samples were evaluated for the percentage of root surface area covered by fungal growth or rot. Rhizomania symptom development was uniform and other disease problems were not evident in the plot area. We were unsuccessful in establishing plants for entry 24, so data for only 29 entries were collected. The BNYVV susceptible check plots (Check 1 and Red beet) had 100% foliar symptoms and high root disease ratings. Resistant check 3 had 0 % foliar symptoms and a low root rating which indicates that resistance based on two genes is holding up. Single gene resistance (Checks 2 and 4) had foliar ratings ranging from 14 to 24% indicating single gene resistance is not completely effective, but the root ratings were still good. Four entries (4, 8, 13, and 23) had a level of BNYVV resistance similar to resistant check 3 based on both foliar and root ratings. A number of the entries had resistance to fungal rots in storage, but only entries 4, 8, and 13 performed well for all three variables. Some entries may serve as a starting point for identifying additional sources of resistance to BNYVV and storage rots
