Last fall a number of strawberry producers in the Southeastern and Mid-Atlantic states began noticing poor growth in their fields. The pattern of damage varied. Sometimes it was in spots within the fields and sometimes it covered the entire field.
The symptoms included older leaves bright red in color, edges of leaves with a distinct yellowing and dead tissue along the margins of leaves. Similar problems were observed in Florida, North Carolina, Virginia and other southern states.
Dr. Barclay Poling of N.C. Sate University travelled to a producer in Nova Scotia because of the widespread symptoms and the association with bare-root plants and tips. While there, he was told the strawberry virus symptoms had started showing up in the fields at about the same time they were noticed elsewhere. Dr. Bob Martin, a USDA-ARS small fruit virologist, had been called in to collect plant samples for laboratory testing.
Strawberry viruses had never before been known to be a problem, but two viruses were found: Strawberry Mild Yellow Edge Virus (SMYEV) and Strawberry Mottle Virus (SMoM). Experts believe it is the combination of the two viruses in the same plant that is causing significant problems for strawberry growers. Most of the plants tested can be sourced back to the one infected nursery in the Great Valley area of Nova Scotia.
The viruses found in the strawberry plants are spread by aphids. These insects must feed on plants containing the virus to transmit the virus by moving to nearby healthy plants to feed. The aphids differ in how long they must feed to get the virus and how long they can spread the virus.
Growers are being reminded that only plants from the Great Valley area of Nova Scotia should be at risk. There is no cure for plant virus infections, so the focus should be on preventing the spread to healthy plants. If aphids are present, insecticides can be used to control them. Plants stunted and showing symptoms from Nova Scotia should not be carried over after this season’s harvest, which may be drastically reduced.
This virus problem is another plant disease issue that is being aggressively worked on by those in all areas. Plan to visit your local strawberry grower this spring. Steven Porter, Steve Putman and TC Smith are all expecting good crops of berries.
There will be several varieties to choose from, and plants are looking good. Harvest should begin after the first of April. The plants they are growing are not from the Canadian source with the virus infection. Visit them at the Lenoir County Farmer’s Market for some delicious fresh local strawberries.
Peg Godwin is horticulture agent, Lenoir County Cooperative Extension Center. Reach her at Peg_Godwin@ncsu.edu or 252-527-2191.
