Types

• Sooty mold is often found in citrus trees producing lemons and oranges. It is characterized by a black, crusty fungal growth on tree parts. Sooty mold does not kill citrus trees because it grows on the plant surface. This condition is usually caused by sucking insects such as aphids, which produce a sticky substance known as honeydew. Sooty mold grows on honeydew on the affected tree.
  
  

Symptoms

• Citrus trees with sooty mold have a black fungus growing on fruit, leaves, branches and stems. Rubbing the fruit removes the mold. Wilting is more common in citrus trees with sooty mold if the tree is under drought stress. Heavy sooty mold infections block the tree's sunlight, resulting in reduced vigor and placing the tree at risk for other diseases and infections.
  
  

Control

• Controlling sooty mold in citrus trees is accomplished with insect control. Chemicals are often used to eliminate mold-causing insects. Spraying citrus trees with a forceful stream of water is another way to knock mold-causing insects from the citrus tree.