Led by Bragato Research Institute in partnership with A Lighter Touch, a new project aims to see if UV-C light can be used in place of traditional fungicides on vineyards.
Led by Bragato Research Institute in partnership with A Lighter Touch, a new project aims to see if UV-C light can be used in place of traditional fungicides on vineyards.
A trial involving robots fitted with UV light panels aims to give grape growers a new alternative to fungicides.
Now under way, the project will involve two years of trials at a Marlborough vineyard growing sauvignon blanc, starting from budburst through to harvest.
The variety grows quite dense canopies that can leave them especially prone to fungal disease.
Led by Bragato Research Institute in partnership with A Lighter Touch, the research project aims to see if UV-C light can be used to control powdery mildew in place of traditional fungicides.
The trial involves an automated machine emitting various frequencies of UV-C light across rows at night.
Bragato research and extension specialist Dr Paul Epee said the process was most effective at night because it prevented the fungus pathogen from regenerating.
“The technology emits UV radiation at an intensity that can damage the DNA of the pathogens and we apply this UV light treatment at night because during the day those pathogens can easily repair the damage to their DNA – because sunlight allows them to repair their DNA.
Epee said there were several benefits to using UV-C light over traditional fungicides used in vineyards that could pose issues.
This included harmful residues impacting wine quality, fungicide resistance and declining soil health and biodiversity.
He said UV light was more “environmentally friendly” and a “good alternative in controlling powdery mildew”.
“UV light does not accumulate in the soil or in the environment and therefore has little negative effects on the microbial diversity.
“UV light does not leave toxic residues on grapes.”
The UV light panels are fitted to viticulture machinery, which is lighter – reducing soil compaction – and are powered electrically, making them more sustainable.
“The technology can also be operated remotely and autonomously,” Epee said, adding this could also reduce labour costs.
The trial involves an automated machine emitting various frequencies of UV-C light across rows at night. Applying the UV radiation at night prevents the fungus pathogen from regenerating.
Technical viticultural specialist Chris Ireland said the aim of the trial was to see if UV worked well in isolation or even as a combination to help reduce fungicide use.
The use of UV-C light technology will be assessed against a standard spray programme also being monitored.
Ireland said they were effectively running two trials – testing how frequently they needed to apply the UV treatment for it to be effective and seeing if growers could reduce fungicide use in their spray programmes by 50% through supplementary UV treatments.
“We are trying to take away some of the sprays that might be going on, putting UV into the traditional sauvignon vineyard and seeing how that compares to the conventional sort of spray programmes.”
A Lighter Touch is running a similar project at Summerfruit New Zealand, with trials under way on a cherry orchard in Cromwell using the technology as a control for brown rot and bacterial canker.
