On Friday, Aug. 11, the U.S. Department of Agriculture announced that the Michigan Department of Agriculture had found the plum pox virus (PPV) in one tree in an orchard at SWMREC. The USDA confirmed plum pox virus in samples collected from a routine survey at SWMREC.
Keeping growers informed is our highest priority. We want you to know that aggressive efforts are underway to manage the PPV. The strain of the virus identified, strain D, is not known to affect cherry trees.
MDA specialists are currently surveying blocks of trees in the immediate vicinity of the infection to determine its extent. We know there is no risk to nonsusceptible crops, to human or to animal health, and we are collaborating with the agencies to analyze the leaf samples that are collected. We hope this will be an isolated situation.
This D strain is the same strain discovered in Pennsylvania in 1999 and later in Canada and New York. It is less virulent than other strains, not as easily transmissible by aphids, and WILL NOT affect the production, harvest or transportation of stone fruit in Berrien County this year because this strain of the virus is not transmitted by fruit or seed. This is a great relief to us.
Right now, it's too early to determine the source of the virus in the tree. PPV can be transmitted by aphids, transplanted trees, or budwood rootstock. USDA and MDA personnel are working to establish both the extent and the origin of the PPV infection at SWMREC. PPV has not been found in any other Michigan location.
The USDA will work with the state and MSU to develop an eradication program that will include extensive detection and delimiting surveys; establishing a quarantine, if needed, in areas where infections are found; and removing infected orchards and other host material within the buffer area of any infection.
To learn more about plum pox
virus, visit:
USDA Animal and Plant Health Inspection Service Web page
Sincerely,
Ray Hammerschmidt, Department of Plant Pathology chairperson
Tom Zabadal, SWMREC coordinator
Bill Shane, MSU Extension district fruit and marketing educator