Entomosporium Leaf Spot on Indian Hawthorne

This fungal leaf spot disease affects woody ornamentals in the rose family including indian hawthorne, red tip photinia, pear, serviceberry, flowering quince, and firethorn. Entomosporium leaf spot became so severe on red tips that the plant is no longer used in the landscape. How can we protect Indian Hawthorne from this leaf spot disease?

Disease Symptoms:

Symptoms on foliage are distinct circular red lesions with gray centers forming as the lesions expand. Dark specks (fruiting bodies of the fungus) may be visible within the gray centers. Spots may also develop on the petioles and new shoots. Badly infected leaves often fall and plants may look thin. Repeated loss of the leaves results in weak plants and dieback of branches.

Disease Management:

Cultural practices are important in controlling Entomosporium leaf spot.

• Plant varieties of Indian Hawthorne that are not susceptible to Entomosporium leaf spot. Good plant selection will give 'permanent' control of this disease.

Resistant varieties include Olivia, Eleanor Tabor, Indian Princess, Gulf Green, Georgia Petite and Georgia Charm.

Susceptible varieties include Bay Breeze, Cameo, Springtime, Pinkie, Enchantress, Heather, Snow White, Clara, Ballerina, Bay Breeze, Cameo, Elizabeth and Kathy.

• The disease is favored by moisture on the leaves. Avoid wetting the foliage when watering. Use drip irrigation.
• Water from 10 pm to 10 am. Water deeply and infrequently.
• Plant in full sun areas. Plant farther apart so plant leaves dry more quickly.
• Selective pruning to reduce the number of branches can increase air circulation through the plant and reduce disease incidence.
• Infected leaves serve as a survival site for the fungus between infection periods. Rain or overhead irrigation splashes the fungal spores from infected to healthy leaves. Remove severely infected leaves on the plant and fallen leaves from the area and throw them away.
• The fungus prefers to infect tender, young leaves. Practices that encourage new growth during the growing season, such as pruning and fertilization, should be avoided.
• Infection occurs primarily in the milder weather of the spring and the fall, especially during periods of rain. During this time, fungicides can be used preventatively on plants with a history of severe infections. Refer to the Georgia Pest Control Handbook for specific fungicide recommendations.