The French wine and vine institute (IFV), a member of NOVATERRA consortium, has been conducting a series of trials to evaluate biosolutions on the downey mildew and powdery mildew platforms.
Sufficient disease pressure in the Nîmes area has allowed to evaluate the efficiency of biocontrols which are in the process of being registered and may at term replace the use of plant protection products. Despite a very dry year, significant mildew pressure occurred during the flowering period thanks to the control of contamination and spraying cycles.
The biosolutions have been testing alone throughout the whole season.
The results of the different solutions tested on powdery mildew are very much encouraging. With a pressure of around 85% on bunches (severity), the efficacy of certain solutions is around 80%. However, the results for downey mildew remain disappointing. Further analyses will be carried out, but on average the efficacy on bunches is around 30% for a pressure of around 20% (severity).
This graph represents the frequency (number of organs affected) and severity (percentage of presence of symptoms on the organ). It shows that biocontrols tested do not reduce the frequency of disease but do have an effect on the severity.