There is a need to develop alternative or complementary solutions for pesticides that are effective, safe and more climate friendly. Especially in grapevine (Vitis vinifera), the control of downy mildew (Plasmopara viticola) and powdery mildew (Erysiphe necator) is critical for producing high quality wine; yet it requires significant agrochemicals input depending on environmental conditions over the growing season. Recently, a pioneering study has provided evidence of the effectiveness of UV-C light at reducing the incidence of downy mildew in grapevine, already knowing that it is effective in controlling powdery mildew. Therefore, in this work we have tested the hypothesis that the application of UV-C light may be effective as an alternative to agrochemicals for the control of downy mildew in grapevine under field conditions. In spring 2022, we employed the robotic platform Thorvald™ from Saga robotics™ to treat grapevines of Glera cultivar in northern Italy. The experiment was a randomised block design and morpho-physiological assessments were carried out weekly from budburst. We identified specific dosage of UV-C with promising downy mildew suppression up to 60% when compared to the control untreated. Although the experimental work should be replicated in further field trials, we observed significant effects of UV-C on stomatal dynamics, suggesting that the reduction in downy mildew intensity may also be associated with UV-C induced stomatal priming. Thus, this study highlights that if UV-C is correctly applied, reduction on pesticides can be achieved also for the treatment of downy mildew and that the Thorvald platform can enable farmers in the application. Unfortunately, the reduction in downy mildew intensity was consistently lower compared to chemical control and this research is stressing for further investigations on the topic.     «

There is a need to develop alternative or complementary solutions for pesticides that are effective, safe and more climate friendly. Especially in grapevine (Vitis vinifera), the control of downy mildew (Plasmopara viticola) and powdery mildew (Erysiphe necator) is critical for producing high quality wine; yet it requires significant agrochemicals input depending on environmental conditions over the growing season. Recently, a pioneering study has provided evidence of the effectiveness of UV-C...     »