Silver leaf is a fungal disease of the xylem tissues of many various species of fruit trees. Caused by t he fungus Chondrostereum purpureum, it is commonly found in riparian areas containing hardwood trees such as willows, poplar, birch, and oaks. Figure 1: Padre leaves showing symptoms of silverleaf (left) versus leaves from a healthy Padre tree (right). A farm call this week brought me to an orchard showing signs of silver leaf infection. Silver leaf is so named because of its ability to make laves appear silver in color (Figures 1 and 2). This appearance is due to a toxin produced by the fungus that is carried through the xylem to the leaves. Once within the leaves, it creates a separation between the epidermis and palisade layer, creating an air gap that interferes with the normal interception of light. As the disease progresses, leaves curl upward at the edges and turn brown (Figure 3). Scaffolds will eventually collapse, shortly followed by tree death. Figure 2: Close up comparison of a Padre leaf showing symptoms of silverleaf (left) versus a healthy leaf (Right). Irregular cankers found within the xylem tissue of dead and/or dying branches is another characteristic symptom of the disease (Figure 4). In later stages of tree decline, spore-bearing conks or shelf like mushrooms form in the fall. Generally found on the north side, these mushrooms are gray to white in appearance and have a smooth, purplish lower surface. The spores from the mushrooms can infect neighboring trees, and are released upon rain events. Exited spores are moved by the wind and the mushrooms can produce spores for 2 years. Figure 3: Severe infections of silverleaf are characterized by curled leaves and necrotic margins. Wounds with exposed xylem or sapwood or vulnerable to infection. This includes pruning wound