Robots fitted with ultraviolet light lamps that roam vineyards at night are proving effective at killing powdery mildew, say researchers at Cornell AgriTech in Geneva, New York, who are working with Norway’s SAGA Robotics.
Two such robots are conducting field trials on Chardonnay grapes at two sites in New York State. “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.
The UV-light technique is a breakthrough against powdery and downy mildew, which can adapt to chemical antifungal sprays in a single season. “Everywhere grapes are grown, growers have to worry about powdery mildew,” added Lance Cadle-Davidson, a research plant pathologist at the USDA’s Grape Genetics Research Unit. “A typical grape grower will spray chemical fungicides for powdery mildew management between 10 and 15 times each year.”
UV light damages DNA, although many organisms have developed biochemical defences against this damage. “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. Using robots overcomes the issue of finding labour to drive tractor-mounted machines at night.
Photo source: Cornell University