Robots fitted with ultraviolet light lamps that roam vineyards at
night are proving effective at killing powdery mildew, a devastating
pathogen for many crops, including grapes.
Researchers at Cornell AgriTech in
Geneva, New York, have partnered with SAGA Robotics in Norway to
develop the first commercial robotic units, and the autonomous vehicle
robots will appear on the market this year.
This spring, the
researchers are using two such robots to conduct field trials on
Chardonnay grapes at two sites – Cornell AgriTech’s research vineyards
in Geneva, and at Anthony Road Wine Co. in Penn Yan, New York.
“For
Chardonnay grapes, we’ve got effective suppression of powdery mildew
over a period of two years, with treatments once a week,” said David Gadoury, senior research associate in the Department of Plant Pathology and Plant-Microbe Biology at Cornell Agritech, who leads the project.
The
UV-light technique is a breakthrough against powdery and downy mildew,
which can adapt to chemical antifungal sprays in a single season,
costing chemical companies hundreds of millions of dollars in
development, along with environmental impacts.
“Everywhere grapes
are grown, growers have to worry about powdery mildew,” said Lance
Cadle-Davidson, 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,” said Cadle-Davidson, who
is also an adjunct assistant professor in Cornell’s Department of Plant
Pathology.
Powdery mildews have co-evolved with the plants they
attack over millions of years and often develop resistance to chemical
treatments very quickly. But their evolution has also given them an
Achilles heel: adaptation to natural cycles of light and dark.
UV
light damages DNA though many organisms have developed biochemical
defenses against this damage, which is triggered 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,” Gadoury said. “At night,
the pathogens don’t receive blue light and the repair mechanism isn’t
working.”
The researchers use lamps that deliver a low dose of UV
light, killing the pathogen without harming the plant. The technique has
also proven effective against downy mildew and some insect pests.
In
earlier trials, researchers used an array of UV lamps mounted on a
tractor wagon. But the method is less practical due to the all-night
labor required to treat a vineyard. The robots are autonomous vehicles
fitted with 8-by-4-foot arrays.
“These machines will work seven nights a week, all night long,” Gadoury said.
“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,” Cadle-Davidson said. “Our long-term vision is we’ll couple
these detection and treatment approaches across the vineyard in an
automated way.”
For additional information, see this Cornell Chronicle story.
