Situation of Rhizomania in United States
Beet necrotic yellow vein furovirus (EPPO A2 quarantine pest), causing rhizomania, has been reported in United States in the following States: California (first found in several of the important sugar beet production areas in 1983, and reaching over 30.000 ha by 1989), Texas (first found in 1985 in one farm near Hereford) and papers published in 1993 mentioned its occurrence in Idaho (first found in 1992), Nebraska and Wyoming. In 1990 and 1991, surveys have been carried out in Texas and in New Mexico to determine the incidence of rhizomania, beet distortion mosaic virus and an unnamed soilborne sugar beet virus designated as Texas 7 (also transmitted by Polymyxa betae, morphologically similar to beet necrotic yellow vein furovirus but serologically different). Soil samples have been collected, sugar beets were planted in these samples and root tissues were then analyzed by ELISA. Beet necrotic yellow vein furovirus was found in eight of the ten sugar-beet growing countries in Texas and in one county of New Mexico. The unnamed virus Texas 7 was found in five counties in Texas, alone or in combination with rhizomania. Beet distortion mosaic virus has been found in four Texas counties and in one county in New Mexico. The authors noted that due to the widespread distribution of rhizomania in Texas, as in California, quarantine measures are pointless though strict control measures are being taken to slow further spread of the disease.
Sources
Heidel, G.B.; Rush, C.M. (1994) Distribution of beet necrotic yellow vein virus, beet distortion mosaic virus, and an unnamed soilborne sugar beet virus in Texas and New Mexico.
Plant Disease, 78 (6), 603-606.
Duffus, J.E.; Liu, H.Y. (1987) First report of rhizomania of sugar beet from Texas.
Plant Disease, 71, p 557.
Duffus, J.E.; Whitney, E.D.; Larsen, R.C.; Liu, H.Y.; Lewellen, R.T. (1984) First report in western hemisphere of rhizomania of sugar beet caused by beet necrotic yellow vein virus.
Plant Disease, 68, p 251.