Technical Abstract: Twenty-two sugar beet (Beta vulgaris L.) lines from the USDA-ARS Ft. Collins sugarbeet program were screened for resistance to Beet severe curly top virus (BSCTV) and other closely related Curtovirus species in 2011. Commercial cultivars Monohikari and HM PM90 were included as susceptible and resistant checks, respectively. The curly top evaluation was conducted at the USDA-ARS North Farm in Kimberly, ID which has Portneuf silt loam soil and had been in barley in 2010. The field was plowed both in the fall and the spring, fertilized (80 lb N and 120 lb P2O5/A) on 20 Apr 11, sprayed with Ethotron (2 pt/A), and roller harrowed. The germplasm was planted on 16 May. The plots were two rows 10 ft long with 22-in row spacing, arranged in a randomized complete block design with three replications. The field was sprinkler irrigated and hand-weeded as necessary. Plant populations were thinned to about 47,500 plants/A on 19 Jun. Plants were inoculated at the four to six leaf growth stage on 27 Jun with approximately six viruliferous beet leafhoppers per plant. The plants were sprayed with Lorsban 4E (1.5 pints/A) on 11 Jul to kill the beet leafhoppers. The plots were rated for foliar symptom development on 18 Jul using a scale of 0-9 (0 = healthy and 9 = dead; Mumford 1974), with disease index (DI) treated as a continuous variable. Data were analyzed using the general linear models procedure (Proc GLM-SAS), and Fisher’s protected least significant difference was used for mean comparisons. Curly Top development was uniform and no other disease problems were evident in the plot area. The experiment was rated only 3 weeks after inoculation, because by 4 weeks some of the more susceptible entries died and thus some of the differences among entries were no longer apparent. Three experimental germplasms were not significantly different from the most resistant control.