Importance. -- Actinopelte leaf spot can reach epidemic proportions and cause major loss of foliage. Growth losses, increased stress on the tree and unsightly conditions result. Overall, the disease normally remains endemic and causes foliage loss only in the fall, with no subsequent effect.

Identifying the Fungus. -- Small, brown, dot-like fruiting bodies are formed on the necrotic tissue. Spores are elliptic and clear or colorless and can be microscopically observed by crushing a fruiting body.

Identifying the Injury (figure 69). -- Round to irregular, red-brown spots develop along the leaf veins. The spots are normally surrounded by light brown areas and may merge to kill large areas of the leaf in late summer. Small twig cankers may be formed.

Biology. -- The fungus overwinters in the affected twigs and foliage. Spores of the fungus are spread by wind and rain-splash the next growing season.

Control. -- Collect and dispose of fallen leaves. Remove unneeded branches to increase air movement. Fertilize to increase vigor and use fungicide sprays.