Brown Spots on a Mulberry Tree

Cause

• The bacterial disease known as bacterial blight caused by Pseudomonas syringae leads to the appearance of brown spots on mulberry trees. The disease symptoms are more pronounced during wet season.

Symptoms

• Initial symptoms of bacterial blight include the appearance of irregularly shaped, brown-colored spots on foliage, flowers and stems. On fruiting mulberry trees, the lesions also spread to the fruit. The brown lesions are usually accompanied with cankers and streaks in the wood.

Management

• Avoid planting trees in areas with poor air circulation, and do not use overhead sprinklers. Overfertilized trees are more susceptible to the disease. Try to use resistant varieties. In case of severe infection indicated by cankers on tree trunk, remove the entire tree. There are no effective chemical control options for the disease.