Emerging disease is killing young plants in Virginia, county warns

Any Fairfax County residents who recently bought a budding tree or shrub may want to keep an eye on its leaves.

A relatively new disease called vascular streak dieback is killing plants from nurseries in Virginia and five other states, the Department of Public Works and Environmental Services’ (DPWES) Urban Forest Management Division says.

“Dieback may look like yellowing or paling of the leaves’ green color (leaf chlorosis), brown or scorched leaf margins and stunting and/or wilting of current year’s growth,” DPWES said in a press release on Tuesday (Oct. 3).

In Virginia, the plants that appear to be most susceptible to the disease are maple, dogwood and redbud trees, according to Virginia Tech and the Virginia Cooperative Extension (VEC), which have cataloged 21 different affected woody ornamental plant species, as of March.

First detected in cacao in Papua New Guinea during the 1960s, vascular streak dieback was mostly confined to southeast Asia until the past couple of years. The Virginia Department of Agriculture and Consumer Services (VDACS) confirmed that the disease had emerged in the state last year.

Researchers have traced the disease to a fungus called Ceratobasidium theobromae, whose spores get carried from plant to plant by the wind, according to DPWES.

“After a spore infects a leaf, it travels into the branch and the main stem’s woody tissue, eventually killing the plant,” the department says. “Researchers continue to study VSD, and the fungus related to it, to find ways to prevent infection and the potential spread into the natural environment.”

Available data on how to prevent VSD is limited, but Virginia Tech and the VEC say it can help to minimize stress on plants by ensuring they have the right amount of soil, water and other conditions needed to stay healthy.

Here’s more from DPWES:

Virgina Cooperative Extension recommends that nurseries ensure best management practices of plant stock to prevent chances of infection. Residents looking for trees in nurseries may consider asking nursery staff about vascular streak dieback and if the internal woody tissue may safely be checked for VSD before purchasing. Also, look for any signs of scorched leaves and buds or dieback of young stems. If VSD is suspected in a recent purchase report it to the Virginia Cooperative Extension and dispose of the plant material correctly to prevent its potential spread. Plants, or the suspected live branches, also may be bagged and either taken or mailed to the Extension, where the disease can be positively identified. If mailing, a two-day delivery is best to avoid damage to live tissue.

The county’s urban forest management team has also been combatting a beech leaf disease that emerged in the area last fall and the invasive spotted lanternfly, which feeds on trees, shrubs and herbs “in unusually large numbers,” DPWES has said.

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