Jun 4 2020
Robots installed with UV lamps and wandering through vineyards at night have been found to be effective at destroying powdery mildew, a catastrophic pathogen for various crops, including grapes.
The UV light robot named Thorvald, applies treatment on grape vines in a Cornell AgriTech research field at night. Image Credit: David Gadoury/Provided.
At Cornell AgriTech in Geneva, New York, researchers have collaborated with SAGA Robotics in Norway to create the first commercial robotic units—autonomous vehicle robots that will reach the market this year.
This spring, the team is using two such robots to perform field trials on Chardonnay grapes at two sites—at Anthony Road Wine Co. in Penn Yan, New York, and at Cornell AgriTech’s research vineyards in Geneva.
Research works at Cornell on the application of UV light to destroy grapevine powdery mildew date back to 1991. Over the last four years, field trials in collaboration with the University of Florida have been successful in controlling powdery mildew in strawberries.
The most recent grape trials were successful in controlling not only powdery mildew but also another destructive disease known as downy mildew. Partnerships with other universities have also enabled trials with pumpkins, squash, hops, cucumbers, industrial hemp, and basil.
For Chardonnay grapes, we’ve got effective suppression of powdery mildew over a period of two years, with treatments once a week.
David Gadoury, Senior Research Associate, Department of Plant Pathology and Plant-Microbe Biology, Cornell Agritech
Gadoury is the project leader.
The UV-light method is a progress against downy and powdery mildew, which has the capability to adapt to chemical antifungal sprays in a single season and costs chemical companies hundreds of millions of dollars in development, besides environmental impacts.
“Everywhere grapes are grown, growers have to worry about powdery mildew,” stated Lance Cadle-Davidson, PhD ’03, a research plant pathologist at the Grape Genetics Research Unit at the United States Department of Agriculture’s Agricultural Research Service in Geneva, and a partner on the project.
“A typical grape grower will spray chemical fungicides for powdery mildew management between 10 and 15 times each year,” noted Cadle-Davidson, who is also an adjunct assistant professor in Cornell’s Department of Plant Pathology.
Over millions of years, powdery mildews have co-evolved with the plants they destroy and usually tend to quickly develop resistance to chemical treatments. However, their evolution has also given them a vulnerable characteristic—adapting to natural cycles of light and dark.
DNA gets damaged when exposed to UV light, though various organisms have developed biochemical defenses against such damage, which is activated by blue light found in sunlight.
What makes it possible for us to use UV to control these plant pathogens is we apply it at night. At night, the pathogens don’t receive blue light and the repair mechanism isn’t working.
David Gadoury, Senior Research Associate, Department of Plant Pathology and Plant-Microbe Biology, Cornell Agritech
The researchers also used lamps that emit a low dose of UV light, which destroys the pathogen without any harm to the plant. The method has also been found to be effective against downy mildew and certain insect pests.
In previous trials, an array of UV lamps mounted on a tractor wagon was used by researchers. However, that technique was not so viable due to the all-night labor needed to cover a vineyard. By contrast, the new robots are autonomous vehicles installed with 8-by-4-foot arrays.
“These machines will work seven nights a week, all night long,” added Gadoury.
In addition, Cadle-Davidson has been developing imaging technology in collaboration with researchers at Carnegie Mellon University that will identify and measure the amount of mildew on grape leaves.
We’re right now on version 1.0 of this UV robot treatment, which applies the same dose of UV light to every vine regardless of whether it’s sick or healthy. Our long-term vision is we’ll couple these detection and treatment approaches across the vineyard in an automated way.
Cadle-Davidson, Adjunct Assistant Professor, Department of Plant Pathology, Cornell University
The international, multi-institutional research group includes assistant professors Katie Gold and Yu Jiang from Cornell AgriTech, Natalia Peres from the University of Florida, Mark Rea from Rensselaer Polytechnic Institute’s Lighting Research Center, and Arne Stensvand from Norway’s Institute of Bioeconomy. The work covers disciplines from physics and lighting technology to plant growth and photobiology.
The study was financially supported by grants from the USDA, the Research Council of Norway, and the New York Farm Viability Institute. Additional support was also provided by lighting companies OSRAM and the Asahi Glass Co.