According to scientists at Cornell University and the University of Connecticut, a popular cultivar of white pine blister rust, the immune black currant (Ribes nigrum cv. Titania), has now lost it’s immunity to Cronartium ribicola, the white pine blister rust fungus.  This is significant in that development of Ribes cultivars highly resistant or immune to white pine blister rust has resulted in the relaxing in other states of the quarantine regulations Ribes plants, and specifically on black currants. 

Fortunately for Maine, the Maine Forest Service has maintained its quarantine on Ribes importation and cultivation for over ninety years.  However, both New York and Massachusetts have initiated a significant currant/gooseberry fruit industry based on putatively “immune” Ribes cultivars, which may now be at-risk of developing the rust disease, as well as jeopardizing nearby white pine stands.

The report was recently published in the journal Plant Disease (First Report of White Pine Blister Rust Caused by Cronartium ribicola on Immune Black Currant Ribes nigrum cv. Titania in Preston, Connecticut).  The report abstract can be found here:

http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-07-11-0609?journalCode=pdis

For information on the White Pine Blister Rust may be found at this website.