Symptoms

• The fungus appears as a white to gray-colored powdery mildew that covers leaf surfaces. It begins life as circular, powdery white spots that expand and produce a similar coating of dust.
  
  

Leaf Drop

• Powdery mildew can infect plant tissue and result in leaf drop and poor plant growth. Some plants and tree species can be severely affected by leaf drop, but for others, such as lilacs, powdery mildew has little impact. Infection of the disease can also distort leaves, buds and fruit.
  
  

Effects on Poplar Trees

• The fungus is not considered serious for shade trees in North Carolina, such as poplar trees, as it does not appear until late summer or early fall, leaving insufficient time in which to cause extensive damage.
  
  

Favorable Conditions

• Site conditions that have a humid environment are more prone to powdery mildew. It also thrives during periods of high relative humidity, or in areas densely planted with plants and trees.
  
  

Life Cycle

• During winter the fungus survives on debris, such as fallen leaves or infected plant parts. In spring, spores are carried by wind to different leaves, where new infection begins.