Detection of rhizomania in Minnesota (US)
In Minnesota (US), several sugarbeet fields showed patches of pale greenish yellow foliage and upright leaves characteristic of rhizomania (beet necrotic yellow vein furovirus – EPPO A2 quarantine pest). Other symptoms observed included reduced root size and root proliferation. Samples were taken in August 1996 and tested (ELISA, Western blot, inoculation to Chenopodium quinoa and Beta macrocarpa). Beet necrotic yellow vein furovirus was identified in 59 of the 90 sugar beet samples tested. Sugarbeet plants showing foliar vein clearing, vein banding, mosaic and vein necrosis were all found to be infected by beet soilborne mosaic furovirus. In addition, beet soilborne furovirus was also found in three samples. This is the first report of these three furoviruses in Minnesota. The authors also noted that the distribution of rhizomania observed in the fields suggests that the disease has probably been present in previous crops without being detected.
Wisler, G.C.; Widner, J.N.; Duffus, J.E.; Liu, H.Y.; Sears, J.L. (1997) A new report of rhizomania and other furoviruses infecting sugar beet in Minnesota.
Plant Disease, 81(2), p 229.