Germicidal ultraviolet light is effective at killing a damaging fungus that infects table beets, adding an important organic tool to fight the growing problem of fungicide resistance, according to a new Cornell study.
While UV light is already used to fight powdery and downy mildew in grapes, powdery mildew in strawberries, and a contagious bacteria that causes fire blight in apples, pears, and members of the family Rosaceae, this is the first proof that the germicidal light can work in a vegetable.
Fire blight and powdery and downy mildew live on the outside of leaves and shoots, but this study shows UV light suppresses Cercospora leaf spot fungus, which has part of its lifecycle inside the plant.
"Cercospora leaf spot infects the leaf and causes defoliation, and therefore, because table beets are harvested with what's called top-pulling machinery—machines that grab the roots and pull the roots out of the ground—when the leaves are gone, they don't work," said Sarah Pethybridge, associate professor of plant pathology and plant-microbe biology at Cornell AgriTech and corresponding author of a study published in Plant Disease.
Read more at phys.org