Apple Scab Apple scab is a fungal disease that attacks the foliage of apple trees and related species. Leaves exhibit brown necrotic areas that gradually enlarge and cause premature leaf drop, defoliating a large portion of canopy. Repeated infections lead to a general weakening of tree. This is a systemic fungal disease that infects a wide variety of trees and shrubs and causes visible cankers and limb die-back. This systemic fungal disease is most often seen on the Leyland Cypress.
Infected trees exhibit spots of exuding sap along trunk.
Advanced signs include individual branch die-back and tree decline. The first symptoms consist of a yellowing, wilting, and browning of leaves on individual branches, whuich eventually die. Elm leaf margins exhibit browning and yellow halo. Branches , Etc. Don't bring firewood into the city.