Black Spots on Peaches Growing on Trees

Symptoms

• Purple, brown or black spots that appear on the foliage of the peach tree are typically the first symptoms of bacterial spot. Holes appear within the interior of the leaves, followed by a yellowing and premature defoliation. As sunken brown or black spots appear on the fruit, the lesions are surrounded by a soft, water-logged area. In most instances, the spots appear on the side of the fruit exposed to the sun.

Damage

• The black spots on peaches growing on trees often enlarge and may cover a significant portion of the skin. Gardeners may also notice a yellow substance oozing from the lesions after a rainfall and the formation of cracks in the skin. Fruit infected early in its growth period may appear disfigured. Bacterial spot of peach also attacks the twigs of the tree, girdling -- strangling -- them and further reducing the ability of the tree to produce fruit.

Conditions

• The bacteria overwinters on twigs of the peach tree and comes to life in the spring during warm and rainy weather. The disease is easily spread by the wind and splashing water and thrives at temperatures of between 70 and 85 degrees F. Hot and dry weather holds bacterial spot at bay, while it thrives in soils that are light and lacking in richness. Healthy peach trees are less susceptible to the disease than stressed specimens.

Management

• Ensuring that the tree dries quickly is paramount in reducing the likelihood of a peach tree contracting bacterial spot. Your peach tree should be planted in an area that's well drained and receives significant sunlight. Gardeners should avoid clumping trees closely together, as this prevents proper air circulation and hinders the drying of the foliage. If possible, nearby neglected or wild stone fruit trees should be destroyed to prevent their ability to harbor the bacteria.