RIZO-QUICK - POSSIBILITY TO IMPROVE THE F IELD DIAGNOSIS FOR RIZOMANIA

The qualification of a simple rapid method, named Rite-Quick, develope d by NewLab Company, Erkrath/Germany, to detect BNYVV of sugar beet wa s tested in a beet growing area of northern Germany. In this new proce dure test stripes are moistened with sap of suspicious beet roots dire ctly in the field. The stripes can be sent to an ELISA-lab by mail. Fr om July to August 1994 in 74 selected fields with a suspected BNYVV co ntamination, healthy and diseased plants were harvested. Farmers were interviewed to field history and degree of infestation. In a first ser ies stripes were moistened with sap from main roots and in a second se ries with sap from lata al roots, The analysis was done in a lab of Ne wLab Company. But all tested beets were also sent to the Rizomania-Ver suchsstation of IfZ where the samples were examined with a conventiona l ELISA testing. All together 127 mixed samples from 3 belts and 200 s ingle beets were tested. Comparing conventional ELISA testing and the Rizo-Quick method results were identical from 91 to 94%. The frequency of virus finding was higher in lateral roots than in main roots. No r elation was found between the intensity of beard farming and the resul t of the serological evidence of virus. But a good correlation existed between the intensity of vascular browning or the disorder of seconda ry growth in thickness and the virus content.