Ft. Collins sugar beet germplasm evaluated for rhizomania and storage rot resistance in Idaho, 2012

Rhizomania caused by the Beet necrotic yellow vein virus (BNYVV) is a worldwide problem that can lead to loss of tonnage and lower percent sucrose in the field. BNYVV can also reduce the storability of roots. To identify germplasm with resistance to these problems, 18 sugarbeet germplasm lines developed by the USDA-ARS Ft. Collins sugarbeet program and four check cultivars were screened in a field experiment arranged in a randomized complete block design with 6 replications. During the growing season plants were evaluated for foliar rhizomania symptoms. At harvest on 4 October 2012, roots were evaluated for rhizomania symptoms and then placed into an indoor commercial sugarbeet storage building in Paul, ID. Foliar symptoms ranged from 0% for resistant checks to 95% for the susceptible check, indicating good separation of germplasm for BNYVV resistance should have been possible in the field study. BNYVV root ratings ranged from a low of 19 for a resistant check to a high of 32 for one of the susceptible entries at harvest. Fungal growth on the root surface in storage ranged from a low of 12% for an entry with good storability to a high of 71% for the BNYVV susceptible check. Entries 11, 12, and 15 performed well for all variables. Incorporating better resistance to BNYVV and good storability into commercial sugarbeet cultivars should allow for increased yields in the field and improved recovery of sucrose from roots in storage