Entomosporium Leaf Spot on Red Tip

Description:

Leaf spot, caused by the fungus Entomosporium maculatum, is a widespread and destructive disease of red tip (Photinia fraseri) The fungus over winters on infected leaves and branches from the previous year. In the spring during wet weather, spores are released and are dispersed by splashing water and wind to infect new growth. Infection occurs continuously during periods of wet weather. Infection also occurs in the fall during autumn rains. New infections appear as tiny circular leaf spots that are darker red than the surrounding tissue. Older necrotic (dead tissue) spots on photinia have ashen gray centers surrounded by a darker reddish halo. In heavy infections the spots coalesce to form large blighted areas. Infection will spread to twigs causing cankered areas on branches. Heavy infections will cause premature leaf drop resulting in large bare areas. The leaf spot can be easily confused with a physiological leaf spot. The difference is the physiological spot does not have the sunken gray centers characteristic of the fungal leaf spot infection.