|Shock, C - OREGON STATE UNIVERSITY|
|Eldredge, E - OREGON STATE UNIVERSITY|
Submitted to: Biological and Cultural Tests for Control of Plant Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 7, 2006
Publication Date: May 1, 2006
Citation: Strausbaugh, C.A., Gillen, A.M., Shock, C.C., Eldredge, E.P. 2006. Evaluation of commercial sugar beet hybrids for resistance to beet curly top in Malheur County, Oregon, 2005. Biological and Cultural Tests for Control of Plant Diseases. 21:FC040. Interpretive Summary: Beet severe curly top virus (BSCTV) is widespread throughout the western United States. The virus results in dwarfed plants with distorted rolled leaves and yield loss. The primary means of disease control is the use of disease resistant cultivars. In an effort to identify commercial hybrids with acceptable levels of resistance, we evaluated 26 hybrids for resistance to BSCTV based on natural infection. Most of the hybrids had acceptable levels of resistance based on visual symptoms. However, there were considerable differences between hybrids based on root yield and estimated recoverable sugar.
Technical Abstract: Twenty-six commercial sugar beet hybrids submitted to the official variety trials were evaluated for resistance to Beet severe curly top virus (BSCTV). Hybrids were planted in a furrow irrigated sugar beet field and exposed to a natural epiphytotic of BSCTV. Experimental units were arranged in a randomized complete block design with eight replications. Plots were evaluated for BSCTV based on a Disease Index (DI) scale of 0 to 9 (no symptoms to dead) on 16 Sep 2005 by three raters. The moderately severe epiphytotic resulted in uniform disease pressure and significant differences between hybrids for DI, root yield, sugar content, and estimated recoverable sugar. Our disease ratings were positively correlated with (r = 0.82, P < 0.0001) ratings from the 2005 Curly Top Nursery. As expected, there was an inverse relationship (r = -0.63, P = 0.0005) between DI and estimated recoverable sugar.