Carolina Poplar Disease

Carolina Poplars

• Although most people plant Carolina poplars as shade trees, they are not good shade-tree specimens. They start shedding their leaves as early as midsummer, the hottest part of the year, offering little protection from the sun. Its roots grow aggressively into drainage pipes, clogging or breaking them. Flowers form as male or female, and appear as catkins that precede leaves in spring. The Ohio State University Extension describes Carolina poplar as a cross between the black poplar and the cottonwood.

Disease Symptoms

• Cankers are identified primarily by darkened or discolored areas on tree bark. Dying branches with wilted leaves appear on trees. Branch dieback occurs after cankers girdle branches, and dead branches fall because they cannot hold up under high winds. Cankers open up trees to secondary injuries by insects, bacteria and other fungi. These additional injuries accelerate tree decline and cause mortality. Some cankers are stopped soon after formation by defensive reactions of chemicals released from the trees, according to West Virginia University's tree bark research.

Disease Cycle

• Fungal pathogens C. chrysosperma and L. nivea enter Carolina poplar trees through wounds in tree bark. Insects and animals cause these wounds, as can mechanical abrasions from lawnmowers. Infected bark discolors and is covered with pimplelike stippling indicating the fungal pathogen's fruiting bodies, according to Cornell University’s plant disease diagnostic clinic. After infection, reproductive bodies of the causal fungi appear. Spores become airborne or are transported by carriers, such as animals or pruning shears, to new infection sites, spreading the disease.

Disease Management

• Cornell reports no known pesticides applied as preventive agents for Carolina poplar canker disease. They suggest the most effective means of pest management is maintaining healthy tree growth. Cultural practices achieving vigorous growth include deeply watering during drought, fertilizing and not wounding trees. Cutting a wide berth around tree trunks when mowing and not using string trimmers against trunks reduces risk of injury.