In July 2025, the CEO of Vinehealth Australia attended the 8th International Phylloxera Symposium held at the Plant Breeding Department at Hochschule Geisenheim University in Germany.
The department was established in the 1860’s to develop solutions for vineyards in response to the discovery of phylloxera in Germany, as the majority of grapevines were planted on their own roots at that time.
Their focus since then has been on the development of rootstocks for phylloxera resistance/ tolerance, with Borner (the only fully phylloxera resistant rootstock) being developed here. Two new recently released phylloxera resistant rootstocks have also been developed here, that being Vinto and Liberto.
More recently, the department has been developing rootstocks to deal with other pressures like climate change. Interestingly, we were told that in Germany there is a law that states that all vineyards must be planted on rootstock.
On the first day, the head of the department, Professor Dr Kai Vos Fels provided a tour of the facility and the 11ha research vineyard. He showed us new rootstocks being assessed for their performance and developing cross breeding grapevine seeds, leaf galling phylloxera present on rootstock leaves (prolific on S04), over 1000 different clones of Riesling (given the Rheingau wine region, where the University is, consists of 80% Riesling), and the experimental winery and cellar which houses trial wines of different rootstocks.
We then met with Dr Elvira Bleser, who discussed her work on the grapevine virus testing and virus-free plant propagation through somatic embryogenesis. In Germany there are 10 grapevine viruses and Dr Bleser’s laboratory is one of three in Germany doing virus testing. She showed us techniques they are using for somatic embryogenesis and cryopreservation to preserve important old vine material and grow virus free grapevines.
We heard from ten researchers on grapevine breeding and phylloxera. The key topics and conversations at the symposium were based around the need for increased genetic diversity in our rootstock material, the need to continue to breed other phylloxera resistant rootstocks as there was concern that we may see resistance or tolerance decrease over time and with pressure as well as integrating other traits like drought and nematode tolerance, that we should consider breeding scion material that is resistant to phylloxera and that the PIWI (Pilzwiderstandsfähig) grapevines which have been bred for downy and powdery mildew resistance could have phylloxera resistance bred into them too.
Phylloxera research posters were displayed and information from these and other key presentations will be shared in Vinehealth Australia’s e news in coming months. If you have any questions or would like further information about the symposium, please get in touch.