Plum Pox Survey Underway

A survey to determine if the viral disease Plum Pox (also known as 'Sharka') is present in Massachusetts is underway. Craig Hollingsworth, University of Massachsuetts Extension Educator is the coordinator of the survey with the United States Department of Agriculture, Massachusetts Department of Food and Agriuculture, and Polaris Orchard Management cooperating.

Approximately thirty-five orchards will be surveyed in Massachusetts, focusing on those having planted peach trees from Adams County Nursery in Pennsylvania. Adams County is where the disease was first reported in North America in 1999. The procedure uses 30 trees in each orchard, from which four leaves per tree will be collected

On the left, Hollingsworth is collecting leaves from an 'Encore' peach tree (the variety in which Plum Pox was found in Pennsylvania) at the University of Massachusetts Horticulture Research Center in Belchertown.

The leaf samples are shipped overnight to AGDIA, an Elkhart, IN plant tissue analysis lab where an ELISA test is performed to determine presence/absence of the plum pox virus, even if no visual symptoms are present. So far, Hollingsworth says that no positive (for the plum pox virus) leaf tissue samples have been reported from Massachusetts. The survey is also being done in all the important peach producing states throughout the country.

Plum Pox is a very serious disease of most stone fruit, including peaches, nectarines, plums, and apricots.The USDA is very concerned about the potential for further spread and the resultant economic impact on stone fruit growers, so they are conducting the survey nationwide to determine if the virus is present outside of Adams County, PA, where plant material from several towns has even been quarantined to prevent further spread of the disease.

For more information on Plum Pox, see the 'Sharka' web site, http://sharka.cas.psu.edu/