Apple scab is a disease affecting apples and other pome fruit including pear, oriental pear, quince, loquat and crabapple. It reduces yield and quality by attacking both the tree foliage and the harvested fruit. The disease over-winters on orchard floor trash (leaves and other foliage). Spores are released from the trash into the air and ultimately on the new growth in the spring by rainfall. After the primary infection periods are over, secondary infections begin to spread from new infections to uninfected fruit and tree foliage.