Submitted to: Proceedings Washington State Potato Conference
Publication Type: Proceedings
Publication Acceptance Date: May 15, 2008
Publication Date: July 1, 2008
Repository URL: http://hdl.handle.net/10113/10860
Citation: Munyaneza, J.E., Crosslin, J. 2008. Susceptibility of Different Potato Cultivars to Purple Top Disease in the Columbia Basin. pp 67-73, In: Proceedings, 47th Annual Washington State Potato Conference, 5-7 February 2008, Moses Lake, WA. WSPC, Moses Lake, WA. Interpretive Summary: Columbia Basin potato growers in Washington and Oregon have experienced serious outbreaks of potato purple top disease in recent years. This disease caused significant yield losses and reduction in tuber processing quality. Researchers from USDA-ARS Wapato and Prosser, WA, conducted studies to assess the susceptibility of different potato cultivars to purple top disease in the Columbia Basin. It was found that most of the potato cultivars grown in the Columbia Basin are susceptible to the disease and that younger potato plants are more vulnerable to the disease. Also, it was found that this disease was transmitted to potato tubers at a relatively high rate. Information from the present study will help growers in the Columbia Basin make effective management decisions to reduce losses to potatoes due to this disease by protecting susceptible varieties and younger potato plants against insect vectors of this potato disease.
Technical Abstract: Since 2002, Columbia Basin potato growers in Washington and Oregon have experienced serious outbreaks of potato purple top disease that caused significant yield losses and a reduction in tuber quality. The beet leafhopper-transmitted virescence agent (BLTVA) phytoplasma is the causal agent of the disease in the Columbia Basin and this pathogen is transmitted by the beet leafhopper. To gain understanding of the impact of this potato disease in the Columbia Basin, the following research objectives were addressed: 1) assess the susceptibility of important potato cultivars grown in the Columbia Basin to the BLTVA phytoplasma and purple top disease under field conditions; 2) determine susceptibility of different potato plant growth stages to the phytoplasma under field conditions; 3) determine BLTVA phytoplasma transmission rate in tubers; and 4) determine the incidence of the phytoplasma in beet leafhoppers collected from potatoes throughout the growing season. Results showed that most of the potato cultivars grown in the Columbia Basin are susceptible to the purple top phytoplasma; however, Russet Burbank appears resistant to or tolerant of this plant pathogen. Younger potato plants seem more vulnerable to the phytoplasma. BLTVA is effectively transmitted to daughter tubers at a very high rate. A high proportion of beet leafhoppers in potatoes and nearby weeds were found to carry the BLTVA phytoplasma throughout the whole season.