Submitted to: Biological and Cultural Tests for Control of Plant Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 18, 2002
Publication Date: May 5, 2002
Citation: Hanson, L.E., Panella, L.W. 2002. Evaluation of beta pis from the usda-ars npgs for resistance to curly top virus, 2001:. Biological and Cultural Tests for Control of Plant Diseases. Interpretive Summary: Beet Curly top virus is widespread throughout the western United States. It causes beets to be dwarfed with crinkled and rolled leaves. Disease control is largely through the use of disease resistant varieties. Thus the identification of new sources of resistance is important for managing beet curly top. In 2001, 30 Plant Introductions from the USDA-ARS National Plant Germplasm System were tested for resistance to beet curly top virus. The disease was severe this year due to the hot, dry weather. Out of the 30 Plant Introductions tested, 14 were not significantly different from the resistance control at both of the times tested.
Technical Abstract: Thirty Plant Introductions (PIs) from the USDA-ARS National Plant Germplasm System were evaluated for resistance to the beet curly top virus in an artificially inoculated nursery in Kimberly, ID. After the beets emerged, plots were trimmed, thinned, and cultivated. Viruliferous leafhoppers were released to cause an artificial epiphytotic. The field was sprayed two weeks after release to kill the leafhoppers. Plots were visually evaluated and rated on a Disease Index (DI) scale of 0 to 9 (no symptoms to dead) at two different times. An analysis of variance on the disease indices determined that there were highly significant differences (P=0.05) among entries. There was cultivator damage throughout the field and some plots were missing. The summer was very hot and dry and the epiphytotic severe. There were 23 accessions which were not significantly different from the resistant control at the first rating period and 15 at the second, 14 of which were not significantly different at both times. The resistant and susceptible checks had DIs of 4.5 and 6.5 respectively at the first rating, and 4.0 and 6.5 at the second, while the DIs for the PIs ranged from 4.0 to 7.5 at the first rating and 4.0 to 8.0 at the second.