Symptoms

• Disease symptoms are exhibited on both abaxial and adaxial leaf surfaces as orange, rust-colored, dense silky tufts ranging from 5 to 8 mm in diameter.
• Upon scraping away these spots, a thin, grayish white to dark-colored, necrotic crust remains on the leaf.
• These spots usually come together to form large irregular patches on a leaf. As the spots mature they take on a dull, grayish green color.
• Twigs and branches are also affected causing the bark to crack due to the growth and expansion of the pathogens filaments into the cortical tissues of the host.

Management

• Algal leaf spot can be reduced by maintaining tree vigor with cultural techniques such as proper fertilization and irrigation, proper pruning to enhance air circulation within the canopy and sunlight penetration, managing weeds and wider tree spacing.
• Managing insect, mite and other foliar diseases increases tree vigor and lessens susceptibility to this disease.
• Spray Copper oxychloride 0.25%.