Disease Note.

First Report of Beet Soilborne Virus in the United States. K. Lindsten, Department of Plant and Forest Protection, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden. C. M. Rush, Texas Agricultural Experiment Station, P.O. Drawer 10, Bushland, TX 79012. Plant Dis. 78:316,. Accepted for publication 2 November 1993. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0316C.

The furovirus beet soilborne virus (BSBV), first reported in England in 1982, is vectored by Polymyxa betae Keskin and has been identified from sugar beet-growing areas throughout western Europe (1). BSBV is similar in size and shape to beet necrotic yellow vein virus (BNYVV), the cause of rhizomania of sugar beet, but BSBV is less virulent. Sugar beet, the only identified natural host of BSBV, is frequently a symptomless host, and the actual effects of BSBV on sugar beet are unknown. To determine whether BSBV was present in the United States, three to five sugar beet plants were individually transplanted into each of 19 soil samples taken from sugar beet fields in Texas five from Colorado four each from Minnesota, Idaho, Nebraska, and Wyoming and 10 from California. After 1 or 2 wk, bait plants were harvested and tested by DAS-ELISA for BSBV. Root sap was also mechanically inoculated to Chenopodium quinoa Willd., a local lesion host of BSBV. More than 50% of soil samples tested from each state were positive for BSBV. Characteristic symptoms of BSBV also developed on inoculated leaves of C. quinoa. This is the first report of BSBV in the United States and confirms that the virus is widespread in sugar beet-growing areas in this country.