Diseased flowers wilt, turn brown and
are covered with masses of spores.

Brown Rot Blossom Blight

Description

Brown rot blossom blight is a common and destructive disease of all stone fruits including flowering cherry and plum as well as their fruit bearing relatives.

Plants Affected

Flowering and weeping cherry, flowering plum, fruit trees; apricot, cherry, peach, and plum.

Symptoms/Damage

The brown rot fungus can attack blossoms, fruit, leaves, twigs and branches. Disease symptoms appear in the spring after the blossoms open. Diseased flowers wilt, turn brown and are covered with masses of spores. The disease spreads into twigs causing small branch dieback. Profuse gumming may appear on infected branches. Fruit infections appear as soft brown spots and can engulf the whole fruit. Infected fruit and flowers shrink into "mummies" and may persist on the tree until next year.

Life Cycle

Brown rot is caused by a fungus that over winters on infected plant parts. In the spring during wet weather masses of spores are produced that can infect the blossoms and young shoots. The disease will continue infection cycles during wet periods in the spring.

Management

A combination of cultural methods and treatments are needed to control this disease in our wet rainy northwest climate.

Cultural

 Sanitation is very important. Remove and destroy all infected twigs and branches. Remove all rotted fruit.

 Remove wild or neglected stone fruit trees that serve as disease reservoirs.

 Avoid wounding fruit during harvest.

Organic

 Use wettable sulfur or copper during periods of wet weather. See below for schedule.

Chemical

 Apply three to four treatments of an approved fungicide (some are systemic) starting at bud break in the early spring and continue at regular intervals during the spring until dry weather. Thoroughly treat all leaf and twig surfaces. Treatments during blossoming are essential for good control. The wetter and rainier the spring, the worse the disease problem is. Also apply a dormant treatment before fall rains.