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White pine blister rust regulations
Introduction
White pine blister rust (WPBR), caused by the fungus Cronartium ribicola, is a damaging disease of pine.  The fungus infects five-needle pine plants, including eastern white pine (Pinus strobus), western white pine (P. monticola), sugar pine (P. lambertiana), limber pine (P. flexilis), whitebark pine (P. albicaulis), bristlecone pine (P. aristata and P. longaeva), foxtail pine (P. balfouriana), and Mexican white pine (P. strobiformis).  Five-needle pines infected with C. ribicola will display yellow spindle shaped swellings (cankers) on stems and branches.  Cankers eventually surround stems and branches causing girdling, browning of needles, flagging of branches, and sometimes death of plant.  Currant and gooseberry plants (Ribes spp.) serve as obligate alternate hosts.

C. ribicola spread from Europe to North America in the early 1900’s on infected nursery stock.  The fungus is now known to occur throughout much of the United States, including Oregon. WPBR is native to Asia.

Regulations
Oregon has no quarantine against white pine blister rust as the disease is widespread. Due to the obligate alternative host status of currant and gooseberry, other states have regulated Oregon’s shipping of Ribes species. A permit from the destination state is required in Delaware, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, Ohio, Rhode Island, and West Virginia. County restrictions are enforced in the states of West Virginia, Rhode Island, Maine, and Massachusetts. Shipping of all Ribes spp. to North Carolina is prohibited. Detailed state quarantine information can be found on the national plant board website: http://www.nationalplantboard.org/laws/index.html