Cover Crops and Flower Strip Plants as Potential Hosts for Sugar Beet‐Infecting Virus Yellows Species and Their Attractiveness to the Vector Myzus persicae

ABSTRACT Virus yellows (VY), caused by beet chlorosis virus (BChV), beet mild yellowing virus (BMYV) and beet yellows virus (BYV), is a serious disease affecting sugar beet, leading to significant yield losses. The main vector is the green peach aphid Myzus persicae . Beet mosaic virus (BtMV) is often associated with VY due to the shared vector. Different host plants of VY‐associated viruses can play an important role in the aphid's life cycle and the VY‐epidemiology. This study evaluated the susceptibility of 25 cover crops and flower strip plants to VY‐associated viruses as well as their attractiveness to M. persicae . None of the tested plants were susceptible to BYV or BtMV, while Gypsophila elegans tested positive for BChV and 13 species tested positive for BMYV. Seven of these, including important cover crops and flower strip plants such as Linum usitatissimum , Trifolium resupinatum , T. incarnatum and Centaurea cyanus , were identified as new BMYV hosts. Plant attractiveness to M. persicae varied widely. Under field conditions, only a few species, such as Sinapis alba or Raphanus sativus var. oleiferus , showed high levels of natural infestation by M. persicae . However, a field choice experiment revealed that BMYV infection can occur in different plants, even at low levels of M. persicae infestation. Field trials also confirmed that M. persicae can transmit BMYV from infected cover crops to sugar beet. The findings emphasise the potential importance of cover crops and flower strip plants as green bridges in VY‐epidemiology and highlight the need for research in large‐scale field studies.