Influence of beet soil‐borne virus on mechanically inoculated sugar beet

Abstract

Seven‐day‐old seedlings of three different sugar‐beet varieties (Carla, Rizor and Desirée) were inoculated mechanically with the Ahlum isolate of beet soil‐borne virus (BSBV) in crude sap from infected leaves of Chenopodium quinoa. Control plants were mock‐inoculated with sap from healthy C. quinoa. After potting up, the plants were arranged in a randomized block design on nine neighbouring benches in a glasshouse. Plants were sampled after 11 weeks, the fresh weight of the tap roots determined and the presence of virus checked by ELISA. Considerable variation in tap‐root growth was observed between benches. Overall, BSBV inoculation reduced tap‐root weight of Rizor and Carla by c. 20%. Problems arising in attempts to assess yield loss due to BSBV in naturally infected sugar beet are discussed.