Phytophthora ramorum found in Maine.

kennebecjournal.mainetoday.com/news/local/3021943
Saturday, August 12, 2006

State warns of infected lilac shrubs

By CHRISTIAN S. MADORE
Staff Writer

A plant disease that has killed thousands of trees and bushes in California may have just been transferred to Maine.

State horticulturist Ann Gibbs said Friday that a lilac shrub shipped from an Oregon nursery to Agway Garden Centers in Maine has tested positive for the disease Phytophthora ramorum, known as Sudden Oak Death.

In addition to the lilac shrub tested, 13 other lilacs bought from the Oregon nursery were sold by Agway prior to the discovery of the infected bush. They were sold at either Farmingdale, Winslow or Skowhegan Agway locations between late April and June, said Gibbs.

All affected plant material at the centers has been destroyed.

The species of lilac, called Syringa Vulgaris, can be identified by its light purple flower that grows in bunches ranging from 4 to 7 inches long.

Sudden Oak Death earned its name after thousands of oak trees in California became infected in the 1990s.

Since then, the disease has spread to more than a dozen species of plants -- in this case, lilacs.

Symptoms of an affected plant are brown-reddish droplets seeping from the bark of the bush, as well as small discolored spots on its leaves, Gibbs said.

Transmission of the disease occurs most commonly when water carrying the pathogen transfers from one plant to another.

"The sap of one leaf has to touch another leaf," she said.

In 2004, the U.S. Department of Agriculture began regulating the transfer of plants from nurseries in California and Oregon to curb the spread of the disease. Regular surveys over the last three years of more than 70 horticultural business turned up no trace of the disease in Maine, until now.

"I think that this was the first time a positive result was found in this case," said Gibbs.

She said none of federal regulations were broken by either the nursery or Agway. She also stressed that the spread of the 13 shrubs in Maine does not constitute an epidemic.

"We don't even know if the disease can survive in Maine's climate," she said.

If anyone thinks they purchased one of the infected lilacs, they are encouraged to call the Department of Agriculture at 287-3891.

Gibbs said people should only contact the department if their shrub was bought between late April and June and is the species Syringa Vulgaris.

Gibbs said gardeners should not try to prune the bush to eliminate the disease, because that will not help it.

"There's no control for it," she said.

Even if they are not destroyed, the disease usually means certain doom for the infected plant.

Christian S. Madore -- 623-3811 x435

cmadore@centralmaine.com