O operational group FD Control, which took place between 2018 e 2022 and of which the CONSULT she was a partner, studied the role of alternative hosts in the dispersal of grapevine flavescence dorée and scaphoideus titanus populations in the wine-producing sub-regions of Cávado and do Lima. The results obtained confirm the need to maintain disease monitoring and control measures in the region.
The main objective of the project FD Control it went to deepen knowledge on the importance of alternative hosts, including plants, insects and abandoned vineyards, in the spread of grapevine yellows and its main vector, Scaphoideus titanus.
During the execution of the project, evidence was found that Scaphoideus titanus remains in the region. The results also indicate that the presence of other plant hosts and insects infected with the flavescence dorée phytoplasma may increase the likelihood of the reactivation of infection foci and contribute to the spread of the disease whenever the main vector is present in the same area.
The study also identified the existence of secondary vector insects capable of occasionally transmitting grapevine flavescence dorée. Although their transmission capacity is lower than that of Scaphoideus titanus, these insects can contribute to the appearance of new outbreaks of infection, especially in vineyards with a history of the disease. This risk may be aggravated by the simultaneous presence of Scaphoideus titanus, which is responsible for the spread of the disease between grapevines.
The results also highlight the importance of removing host plants located in the surroundings of the vineyards, namely abandoned specimens, ailanthus plants and old man's beard, whenever present, as a containment measure for flavescence dorée.
Based on the conclusions reached, the project recommends that winegrowers and official services maintain a state of alert regarding the risk of the disease spreading via Scaphoideus titanus. Vector monitoring and control, within and surrounding vineyard plots, as well as the removal of diseased vines, are highlighted as crucial measures to limit the dissemination of flavescence dorée in the region. Furthermore, there is the potential for the disease and the vector to spread to neighbouring wine-producing regions.
The project consortium has developed a set of technical recommendations and the manual “Contribution to the knowledge of the epidemiology of grapevine flavescence dorée in the Minho region”, available for enquiry.