As part of our breeding research at the PA/NJ Chapter research orchard at the Arboretum at Penn State, trees are inoculated with a blight to test their resistance. Trees inoculated with blight in 2019 are rated on a scale of 1 to 3 (1 being high resistance, 3 little to no resistance). Trees with a poor rating are culled to reduce competition for better-performing trees. Culled stems are burned on-site to satisfy APHIS permit requirements. So far this season 500 trees have been culled.