Poplars are large trees that thrive in swampy areas and damp riverbanks throughout North Carolina. The wet climate, frequent rainfall and high number of insects make North Carolina a favorable environment for the growth of various fungal diseases that commonly attack the trees. One of the most common of these is known as powdery mildew.
Powdery mildew is a common fungal disease that thrives in humid, moist climates. It most often affects areas with densely planted trees where splashing rainfall can spread the spores and promote growth. Powdery mildew is common on most trees, plants and shrubs in North Carolina wetlands and riverbanks.
During the spring, the powdery mildew fungus releases spores, which are carried through the wind and rain. These spore will cling to the trunks and leaves of various plants in the nearby region. As winter sets in and leaves are lost, the fungus survives by attaching itself to fallen debris or other infected plant parts.
As powdery mildew grows and develops on poplar trees, it begins as circular white spots that will expand in time. This contagion begins to steal nutrients from the plant and use the resources to further reproduce. As the spots mature, they grow into fuzzy mildew that covers mainly leaf surfaces.
As the infection spreads through the leaves, trees become unable to cling to them. The loss of leaves disrupts the tree's ability to carry out photosynthesis and create the food stores it needs to produce buds and seeds. Powdery mildew will distort the natural growth of these plant organs and leave them worthless to the tree.
Powdery mildew infections are not serious threats to larger trees such as the poplar. Since the fungus takes until at least mid-summer to actively spread, it does not have sufficient time to cause serious damage before the leaves are lost and winter sets in. The same disease can still have serious consequences for smaller organisms or leave poplar trees susceptible to further fungal pests.