Question
Howdy! I am trying to find out if anyone has done research to tell which Ribes are more commonly the host to white pine blister rust.(beyond the native) I want to know which are safe to sell. Our area's Limber Pine is reallly being hit. Thanks

Answer
The three species most commonly acting as alternate host for the rust (Cronartium ribicola) are Ribes lacustre, Ribes nigrum  and Ribes viscosissimum. But most folks feel it will infect all Ribes species.

The history of Ribes production in America is of significant interest. Cultivated currants and gooseberries were first introduced in America in the Massachusetts Bay colony in 1629. By the mid-1800's commercial acreage of currants and newly developed European and American gooseberry crosses such as 'Houghton' and 'Downing' were common in the East. In 1899, reported production in the US reached nearly 7000 acres. In the early 1900's, Ribes species were implicated in the spread of white pine blister rust (Cronartium ribicola), a devastating disease for white pine trees that was brought into this country on imported nursery tree stock. Ribes, in particular black currants, are a secondary host to this disease, which requires both pine and Ribes to complete its life cycle.

Red currants and gooseberries exhibit varying degrees of susceptibility. In 1912, federal and state governments introduced restrictions on import, planting and cultivation of Ribes species to protect the lucrative timber industry. Soon after, a sweeping federal law was passed banning only black currants, while some northern states passed outright bans on all Ribes species. A program of eradication of both native stands and domestic plantings was implemented, with Civilian Conservation Corp (CCC) crews doing much of the work.

The federal law was rescinded in 1966, however today laws regarding Ribes culture remain on the books in many states. While some states allow all species to be cultivated, others continue full or partial bans, geographically, or by selected species, namely black currant. Laws banning Ribes species range from being well to poorly enforced or ignored by state officials. Often restrictions vary by township within a state. Across Virginia, growing black currants is still against the law, and enforcement is conducted in nursery sales. Hybridized cultivars (non-pure black currant) that are resistant to white pine blister rust are now available (and legal) and should be selected.

The early Ribes industry was dealt a great setback because of these bans, and has yet to recover. Variable and often confusing legal issues are still an effective roadblock to development of a viable industry. Nevertheless, the threat of white pine blister rust remains a reality today, and site selection in new plantings should take into account the presence of 5 needle pine species, nursery operations in the area, and neighbor relationships.

As long as there is not a pine nursery nearby growing Ribes will not be a problem. In nature the Ribes species are abundant and are normally just dealt with by Foresters in the management of pine.