Wednesday, May 5, 2004

More Sudden Oak Death fungus found on plants imported into Georgia

The Georgia Department of Agriculture has verified the presence of the fungus that causes Sudden Oak Death in eight more Georgia nurseries on camellias imported from Monrovia Nursery in California, a major supplier of plants to nurseries throughout the country.

“We received confirmation from the U.S. Department of Agriculture of testing done at the University of Georgia from samples collected by our inspectors,” said Commissioner of Agriculture Tommy Irvin.

The nurseries have been notified and the plants are being incinerated. The Georgia Department of Agriculture, in cooperation with the United States Department of Agriculture, will do follow up visits to determine what additional regulatory action is necessary.ÊOther states that have also found positive samples are Florida, Louisiana, Oregon, Virginia and Maryland.

Sudden Oak Death is not harmful to humans or animals but is a serious fungal disease that has been killing tens of thousands of oaks in California. Many other plants can act as hosts for the fungus including azaleas, rhododendrons, camellias and maples, but these have not been affected in California the way oaks have.ÊIt is uncertain how the disease will affect plants in Georgia or other Eastern states.

“Currently, we are not recommending digging up and removing plants from the landscape.ÊThis could spread the disease faster and farther.ÊFor example, putting an infected plant in with other yard clippings for municipal pickup would be terrible since most of them are chopped into mulch and put back into the landscape,” said Irvin.

Anyone who has purchased plants that originated from Monrovia Nursery in California should monitor their plants for symptoms.ÊSymptoms of Sudden Oak Death can be non-specific and look like other diseases on many ornamental plants.ÊSymptoms on the foliage can look like leaf spots and blotches, leaf scorch or sunburn.ÊThe lesions may be brown with a bullseye effect with dark brown edges and lighter centers. People seeing these symptoms should contact their county Extension Service office about how to take a sample for possible further testing.

“Nurseries in Georgia have been extremely cooperative and separated out susceptible plants as soon as we notified them of the situation,” Irvin said.Ê“I hope our action along with their cooperation will enable us to eliminate this unwanted threat.”

The eight nurseries from which the positive samples came were: Pike Nursery #2, Marietta; John Deere Landscapes #172, Alpharetta; John Deere Landscapes #57, Lawrenceville; Deep Springs Nurseries, Dalton; Island Ace Garden Center, St. Simons; Still Lake Nursery, Lawrenceville; Southeastern Wholesale Nursery, Norcross; and Sago Inc/Plants Plus, Douglas. Earlier this month positive samples were found in five other Georgia nurseries. Other nurseries where positive samples were taken will be listed on the Georgia Department of Agriculture website as those samples are confirmed.

There is no known cure for Sudden Oak Death once a plant is infected. Fungicides do not eradicate the fungus.ÊThe only known way to control it is by prevention and exclusion; by keeping potentially infected plants out of Georgia.

The genera of plants still blocked from entering Georgia from California are: Acer (maple), Aesculus (buckeye, horsechestnut), Arbutus (strawberry tree, madrone), Arctostaphylos (bearberry, manzanita), Camellia (camellia, sasanqua), Hamamelis (witch hazel), Heteromeles (toyon), Leucothoe (leucothoe), Lithocarpus (tanoak), Lonicera (honeysuckle), Pieris (pieris, andromeda), Pseudotsuga (Douglas fir), Quercus (oak), Rhamnus (buckthorn), Rhododendron (rhododendron, azalea), Rosa (rose), Sequoia (coast redwood), Trientalis, Umbellularia, Vaccinium (blueberry), Viburnum (viburnum, snowball bush, laurustinus), Abies (fir), Castanea (chestnut), Corylus (hazelnut, filbert), Fagus (beech), Kalmia (mountain laurel), Pittosporum (pittosporum), Syringa (lilac), Toxicodendron, Rubus (blackberry, raspberry), and Taxus (yew). (Common names and representative plants from each genus are listed in parentheses after the genus name.)