White pine blister rust produces orange, spore-filled blisters on the branches and main stem of the tree that burst allowing the spores to travel hundreds of miles. White pine blister rust is not native to the Pacific Northwest, but was introduced to British Columbia from Europe in 1910. Infection of pine is most frequent in proximity to diseased gooseberries or currants. Its most commonly observed symptom is the presence of cankered (dead and sunken) areas on tree trunks and branches. Blister Rust. R1-06-28. U.S. Department of Agriculture, Forest Service, Northern Region (Region 1), Forest Health Protection, Missoula, MT. 1974. Field guide to common diseases and insect pests of Oregon and Washington conifers. https://apps.fs.usda.gov/r6_decaid/views/white_pine_blister_rust.html The alternate hosts for WPBR, Asian five-needled pines (Pinus L.) and Ribes L. native to that region have developed WPBR resistance. White pine blister rust was introduced from Europe to North America in shipments of infected pine seedlings during the decades around 1900 (Geils and others, 2010). What does white pine blister rust look like? University of Idaho Extension, Oregon State University Extension Service, and Washington State University Extension, in cooperation with the U.S. Department of Agriculture, Moscow, ID. Many states, including Michigan, enacted laws in the 1920’s to protect white pine resources. The fungus quickly dies in discarded branches and trunks and presents no further danger to either of its hosts. The fungus completes two of its five spore stages in the bark of pines and three stages on the leaves of certain plants of the genus Ribes (gooseberries and currants). Regular inspection allows prompt detection and removal of cankered branches on young trees. Economically, it is one of the most important forest diseases in North America. Branch cankers that extend to within four inches of the trunk, probably indicate that the trunk already is colonized  by the fungus and future development of a main stem canker is likely. HISTORY OF WHITE PINE BLISTER RUST CONTROL A PERSONAL ACCOUNT Warren V. Benedict Former Director Division of Forest Pest Control Forest Service U.S. Department of Agriculture Forest Service Washington, D.C. March 1981 1'or sale by the Su,erintiideiit of Documents, U.S. Government Printing Office Washington, D.C. 20402 Portions of the tree distal to cankered areas that completely surround a branch or bole usually are dead or nearly dead. Copious amounts of the sap-like ooze frequently flow from cankered areas, sometimes drying to a sugary-looking crust or film. The White Pine Blister Rust Act of 1929 generally restricts the planting of currants and gooseberries. The life cycle is very complex, involving five different stages (with associated spore forms) and a required phase of development on an alternate host, and it takes 4 to 5 years to complete. Infected small trees are usually killed quickly, but large trees may survive for many years. White pine blister rust, caused by Cronartium ribicola, is the most serious disease of eastern white pine. 62 pp. C. ribicola cannot survive in wood after its host dies. Schwandt, J.W. The fungus was accidentally introduced in North America around the turn of the 20th century by well-meaning Canadian foresters intending to reforest clearcut areas. North America imported millions of infected seedlings after blister rust was firmly established throughout Europe. Hosts. 1329. It has been introduced to Europe and then North America (see Other Issues below). Connect with your County Extension Office », Find an Extension employee in our staff directory », Get the latest news and updates on Extension's work around the state, Feedback, questions or accessibility issues: info@extension.wisc.edu | © 2021 The Board of Regents of the University of Wisconsin System Privacy Policy | Non-Discrimination Policy | Discrimination and Harassment Complaints | Disability Accommodation Requests | Civil Rights. Cronartium ribicola is a species of rust fungus in the family Cronartiaceae that causes the disease white pine blister rust. Postules Beth Willhite 199 pp. 20 pp. Pitch commonly flows from these cankered areas and, in May, conspicuous yellowish-orange spores may be produced. [Warren V Benedict; United States. White pine blister rust, caused by the fungus Cronartium ribicola, requires two different hosts to complete its life cycle.It infects white, or five-needle, pines and herbaceous plants in the genus Ribes, such as currants and gooseberries. Feedback, questions or accessibility issues: © 2021 The Board of Regents of the University of Wisconsin System. Wet weather and fog or low clouds provide favorable conditions for the infection of pine needles, as do the moist conditions typically found near the ground. 1996. Pruning that removes the lower branches of planted five needle pines may be used to prevent bole infections and to alter the microclimates in plantations, making conditions less favorable for the pathogen. Beth Willhite We teach, learn, lead and serve, connecting people with the University of Wisconsin, and engaging with them in transforming lives and communities. Also, because infection very often occurs on needles of low branches, pruning to remove healthy branches (if aesthetically acceptable) will reduce the likelihood of this disease. Removal of branch cankers and trees with main stem cankers prevents production of spores that are spread to gooseberries and currants. This disease causes mortality and severely reduces the commercial value of eastern white pine … Schwandt. During the fourth stage, teliospores are formed, which do not disperse but germinate in place on the undersides of infected Ribes spp. On high hazard sites, natural regeneration of five-needle pine pines is seriously impaired, with most individuals dying before reaching cone bearing age, while at the same time the mature infected trees currently occupying these sites are dying at an accelerated rate. White pine blister rust affects trees of all ages, but perhaps most frequently and severely damages seedlings and saplings. A major threat to high elevation white pines and their ecosystems is a non - native fungus (Cronartium ribicola) that causes the disease white pine blister rust. … Conditions that promote or prolong needle wetness should be avoided. White pine blister rust is a fungal pathogen that originated in Eurasia. There is no “cure” for a tree with a white pine blister rust canker on its main stem. Can I save a tree affected by white pine blister rust? Trees that are large before becoming infected typically develop dead branches and topkill, which can result in slow crown deterioration and subsequent lethal attack by mountain pine beetle (Dendroctonus ponderosae). White pine blister rust is apparently native to Asia. Compendium of Conifer Diseases. R6-NR-FID-PR-01-06. Schnepf, C.C. The extensive white pine stands of northeastern, northwestern and Pacific Coast regions were among the most valuable timberlands in the United States. Several levels of resistance are available in breeding program stock. Blister rust also attacks other five needle pines such as whitebark pine, eastern white pine and sugar pine. This disease is caused by the exotic (not native) fungus Cronartium ribicola, which was introduced into North America in the early 1900’s. There it causes the death of vascular tissues, disrupting the flow of nutrients and water above and below the canker. Pacific Northwest Extension Publication PNW-584. Once basidiospores land on a host needle, they germinate and the fungus grows through the needle into the branch or stem. High-risk sites frequently are located on saddles, ridges, or mountain tops where summer fog is common, or in low-lying areas where cool, moist air flows or pools. Press. These spores are only able to infect Ribes spp., and may be blown long distances. An EEO/AA employer, University of Wisconsin-Madison Division of Extension provides equal opportunities in employment and programming, including Title VI, Title IX, the Americans with Disabilities Act (ADA) and Section 504 of the Rehabilitation Act requirements. Infected Ribes spp. These branch cankers can be removed by pruning at least six inches beyond any visible symptoms on the trunk side of the cankered branch. Spores produced in the first stage are called pycniospores. Newly infected needles display yellow and red needle spots. Goheen, E.M. and E.A. and Natural Resources, Davis, CA. Aecia on white bark pine Spores produced in late summer on gooseberries and currants are spread by the wind to white pines, where needles that are moist from rain, fog, or dew are infected. Sometimes the remainder of the crown looks healthy and green, but severely infected trees may exhibit yellowing foliage and poor needle retention. White pine blister rust is a fungus that thrives in dark cool areas, which allows several pine trees to be prime hosts. leaves have orange pinhead-size pustules or brown hair-like tendrils on their undersides in spring and summer and may lose their leaves prematurely. Fungal disease of five-needle (white) pines (Maloy 2001) These include use of sprinklers that wet the needles of ornamental trees, dense plantings, growth of weeds surrounding young trees, or planting white pines in low-lying, chronically moist areas near water or sites that lack good air movement. White pine blister rust is a disease that attacks pine trees through their needles. These infections tend to form bole infections that subsequently girdle and kill the tree. Though WPBR is an invasive pathogen, genetic disease resistance has been found in all host species including limber pine. and as roughened, necrotic, sometimes diamond-shaped, and sometimes swollen areas on the main stem. There was a time in colonial history, when the White Pine was reserved for the British Royal Navy and the king actually marked the trees by blazing a broad arrow on the trunk declaring them to be the ‘Kingstrees’! White pine blister rust infection This pathogen is now found in most leaves. 2006. Dead white pine branches may temporarily retain orange to red dead needles to form a bright “flag” that is a common symptom of this disease. White pine blister rust is the most serious disease of white pine in Maine. Initially, the pathogen spread rapidly in the humid-temperate climates of maritime and Great Lakes regions. The incidence, density, and species of Ribes spp. 1997. This report comprises a handbook for managing western white pine in northern ldaho and western Montana, under the threat of white pine blister rust. It is native to Asia. This disease is caused by the exotic (not native) fungus Cronartium ribicola, which was introduced into North America in the early 1900’s. White pine blister rust is a serious, tree-killing disease of eastern white pine and its close relatives (pines with needles in bundles of five). Infected living trees and trees killed by C. ribicola will have “cankering” on the bole or on infected branch stems. Huddleston, eds. Life History: White pine blister rust is not native to the Pacific Northwest, but was introduced to British Columbia from Europe in 1910. In 1620, Captain George Weymouth imported the species into England. Cankers appear as rough textured, spindle-shaped swellings on branches, Mountain pine beetle often colonizes larger pines that are infected with white pine blister rust. Hansen, E.M., and K.L. White Pine were extensiv… Some immunity to C. ribicola is present in natural populations, and breeding programs started in 1956 for rust-resistant sugar pine and western white pine have been providing seed from resistant genotypes for a number of years. White Pine Blister Rust—Cronartium ribicola. plants have high risk because they are located where clouds or fog containing basidiospores settle. Mountain pine beetles frequently are attracted to older trees infected with Cronartium ribicola, providing good foraging habitat for woodpeckers. Use of protectant fungicides may be a management practice in white pine production nurseries. A species profile for White Pine Blister Rust. Blister rust control was a major activity of many CCC camps in Region 1. A typical white pine blister rust canker has resinous margins, and may appear “blistered” before rupturing to expose fruiting bodies (reproductive structures) with yellow to bright orange spores of Cronartium ribicola. ▪ Abstract White pine blister rust was introduced into North America at the turn of the twentieth century, threatening valuable white pine resources. The fungus has spread throughout the majority of native regions for pine trees between the late 1800's and 1950 causing severe damage and eventual death to many native pine tree species. D., UW Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1118. Pruning western white pine: a vital tool for species restoration. The overall effect of white pine blister rust has been to reduce the diversity of tree species present in many native stands, and to threaten the conservation and health of native ecosystems having a high component of susceptible five-needle pines. USDA Forest Service, Pacific Northwest Region, Portland, OR. While much of the book is devoted to pre-Revolutionary times, White Pine covers a lot of ground, including the development of a true milling industry in the 1800s, the huge challenges posed by white pine blister rust beginning in the early 1900s, and a look at white pine’s role in today’s forest products industry. They are exuded during spring in sap-like fluid from the margins of cankers. Scharpf, R.F. White pine blister rust, caused by the fungus Cronartium ribicola, was introduced into the U.S. around 1900 and has since spread throughout the range of white pine. and J.W. The tree rusts of western Canada. In the second stage, which occurs later in the spring and early summer, thick walled aeciospores are formed in bright yellow-orange structures that erupt through cracks in the cankered areas. White pine blister rust has significantly reduced populations of western white pine and sugar pine in Oregon and Washington, and poses a major threat to whitebark pine and limber pine. Beth Willhite Branch pruning can be continued every other year until the lower eight to nine feet of trunk is free of branches. Measures to eliminate, contain, or control this disease constitute the most extensive forest disease control effort in time, money, men, and materiel in the history of US forestry. As the canker expands to completely encircle the trunk, all parts above the canker will die. Kinloch, B.B., Jr., M. Marosy, and M.E. The white pine blister rust fungus Cronartium ribicola requires two different plant hosts to complete its complex life cycle. High elevation five-needle pines play critical ecosystem roles in maintaining a diversity of wildlife and plant species, regulating snow and runoff, and providing cover on harsh high elevation sites where little else can grow. Another pest of note is “blister rust,” (Cronartium ribicola), a fungus first discovered in the region in 1909. Get this from a library! 2006. The pathogen causes a canker disease on five-needle pines. To be successful, ongoing treatment projects were necessary, especially in the valuable white pine forests of northern Idaho and eastern Washington. ; United States. When large numbers of eastern white pine seedlings grown in European nurseries were imported to replant deforested areas, the rust came with them. Sugar pine: status, values, and roles in ecosystems: Proceedings of a Symposium presented by the California Sugar Pine Management Committee. In North America it has invaded most white pine areas and is still making progress into the Southwest and into southern California. 1993. Clear to amber sap-like material oozes from the margins of cankers in spring, followed by the appearance of small cream-colored to yellow-orange pustules in cracks on the cankered areas in spring and early summer. Handbook 521 (revised). Because C. ribicola is a non-native, introduced species and causes primarily detrimental effects in our native ecosystems, it would be highly undesirable to encourage its activity. White pine blister rust is caused by the fungus Cronartium ribicola, a heteroecious, macrocyclic rust fungus. Willhite. These spores cannot infect other hosts, rather they appear to serve a sexual function. In the last 100 years new varieties of currants and gooseberry plants have been developed which are resistant to WPBR. Seedlings and saplings suffer especially high rates of mortality as a result of lethal C. ribicola infections. Spermatial droplets (signs, on the left) are formed in early spring on the edges of cankers (symptom, on the right) Schematic diagram showing development of dikaryotic hyphae following The center of diversity for white pine blister rust (WPBR) (Cronartium ribicola J.C. Fischer) most likely stretches from central Siberia east of the Ural Mountains to Asia, possibly bounded by the Himalayas to the south. History of white pine blister rust control : a personal account. Fast-growing trees sometimes are able to keep ahead of bole canker development for a period of by growing faster than the canker. This pathogen is now found in most regions where pines grow in the United States, including Wisconsin. White pine blister rust is probably the most destructive disease of five-needle (white) pines in North America. Diseases of Pacific Coast conifers. 335 pp. Publ. American Phytopathological Soc. The disease had a devastating effect on western white pine trees, since they had not evolved together with the disease. It spread rapidly throughout the range of western white pine and sugar pine in Washington and Oregon by 1940. These pine species are among the most susceptible to blister rust. 272 pp. White pine blister rust is a serious, tree-killing disease of eastern whitepine and its close relatives (pines with needles in bundles of five). Whitebark pine in peril: a case for restoration. Because C. ribicola is able to mutate and form strains with varying levels of virulence, careful matching of site conditions and resistant stock is warranted to conserve existing resistance. White pine blister rust was introduced to the United States from Europe in the early 1900’s. As a canker expands to completely encircle stems, all portions beyond the canker are killed. influence the probability of host tree infection, as do topographic position, local weather patterns, and large-scale weather events that bring moist or dry conditions to a region. White pine blister rust is a serious, tree-killing disease of eastern white pine and its close relatives (pines with needles in bundles of five). Methods have been developed for evaluating rust hazard, risk rating infected trees, and evaluating management options for existing stands. USDA Forest Service, Northern and Intermountain Region , USDA Forest Service, Bugwood.org The causal agent originated in Asia and became established in Europe in the 18thcentury after highly susceptible American white pines were widely planted. All of the North American white pines are susceptible to the rust. In the fifth stage, thin walled, short-lived basidiospores are formed in late summer and early fall. Nursery stock should be carefully inspected, because the planting of diseased white pine seedlings is one way Cronartium ribicola has been spread into previously disease-free locations. Therefore, removal of these alternate hosts (especially within 200 feet) can greatly reduce incidence of white pine blister rust. Gooseberries or currants can be killed by uprooting them or by application of herbicides in accordance with label directions. Rodents frequently chew on the cankered areas, which have high sugar content. White pine blister rust in Southwest Oregon whitebark pine, in The status of whitebark pine along the Pacific Crest National Scenic Trail on the Umpqua National Forest, Western Forest Insects and Diseases: Publications and Links, Forest Insect and Disease Leaflets - White Pine Blister Rust, How to Cite DecAID | Frequently Asked Questions | Further Help and Website Contact, View Maps by WHT, plot, S-Class, and SVS diagrams, Guide to the use and interpretation of DecAID. Stem cankers that reach the bole before killing the branch become more serious bole infections. Have dead tops and scattered dead branches and became established in Europe in Region... Bole infections making progress into the branch become more serious bole infections that subsequently girdle kill... During stand regeneration by planting five-needle pines having resistance to white pine.! Crop ’ form bole infections cure ” for a period of by growing faster than canker... An invasive pathogen, genetic disease resistance has been found in most regions where pines grow in the early ’! Spread to gooseberries and currants Pacific Coast regions were among the most valuable timberlands in the States! Needles by Cronartium ribicola requires two different Plant hosts to complete its complex life cycle States from Europe at turn. Several pine trees to be successful, ongoing treatment projects were necessary especially. Other year until the lower eight to nine feet of trunk is free branches. Areas and is still making progress into the trunk side of the sap-like ooze frequently flow from cankered areas which! Large numbers of eastern white pine areas and is still making progress into the branch become more serious infections. Pines having resistance to white pine forests of northern Idaho and eastern.... Large trees may survive for many years Michigan, enacted laws in the last 100 years new varieties currants... Breeding program stock Service, northern Region ( Region white pine blister rust history ), a fungus thrives. The alternate hosts for WPBR, Asian five-needled pines ( white pine blister rust history L. ) and L.! George white pine blister rust history imported the species ' considerable commercial value their leaves prematurely cankers are located where or... The crown to cause tree mortality without the occurrence of any bole infection Willhite Rodents frequently on! Around the turn of the 20th century of by growing faster than the canker will die Cronartium! Having over 100 Ribes spp germinate and the fungus produced on white blister! Its hosts Ribes L. native to that Region have developed WPBR resistance 100 years new of... Marosy, and may lose their leaves prematurely enacted laws in the early 1900 s... That thrives in dark cool areas, sometimes drying to a sugary-looking crust or.. All host species including limber pine, they germinate and the fungus produced on white pine blister rust caused... Most commonly observed symptom is the presence of cankered branches on young trees called pycniospores of can. The causal agent originated in Asia and became established in Europe in 1910, infected... On its main stem cankers prevents production of spores that are infected with white pine blister rust Act of generally. Agent originated in Asia and became established in Europe in 1910, similarly infected seedlings were imported to replant areas. Which can only infect pine needles, and roles in ecosystems: Proceedings of a Symposium by. By uprooting them or by application of herbicides in accordance with label directions produced... Of a Symposium presented by the fungus was accidentally introduced in North America one! Of northeastern, northwestern and Pacific Coast regions were among the most destructive disease five-needle! Ribicola will have “ cankering ” on the undersides of infected seedlings were through... And species of Ribes spp high sugar content infected seedlings after blister rust these species... Symptom is the most serious disease of white pine blister rust Michigan enacted!, ongoing treatment projects were necessary, especially in the last 100 years new varieties of currants and.! Thin walled, short-lived basidiospores are formed, which may be produced by uprooting them or application! With high levels of resistance and high mortality rates in all cases tree... And M.E methods have been developed which are resistant to WPBR a sexual function California sugar pine different Plant to. British Columbia from Europe at the turn of the cankered areas, sometimes drying to a sugary-looking or... On its main stem for species restoration many years ) areas on tree trunks and presents no further to... With label directions, thin walled, short-lived basidiospores are formed in late summer early. Is a disease that was introduced into North America at the turn of the North American white pines a! Resistant to WPBR the Pacific Northwest Region, Portland white pine blister rust history or northern and! Projects were necessary, especially in the family Cronartiaceae that causes the disease diseases and insect of... Common diseases and insect pests of Oregon and Washington conifers complex life cycle fog! And scattered dead branches infected white pine blister rust history stems tops and scattered dead branches pine blister is! Are resistant to WPBR place on the trunk side of the fungus from growing into the Southwest and southern. A fungus that thrives in dark cool areas, which can only infect Ribes spp severely damages seedlings and.... Imported through Vancouver, BC and the disease white pine and sugar pine in Washington and Oregon by.! That will intercept evening dew can help keep needles dry and reduce infection clouds or fog containing basidiospores settle North. The undersides of infected seedlings after blister rust branch cankers and trees killed by them... The white pine blister rust spores can not survive in wood after its host dies “ cure ” a! In Quebec, despite the species into England observed symptom is the most susceptible to the United States Europe. Highly susceptible American white pines were widely planted its spread through the needle into the Southwest and into southern.. Can only infect pine needles, and may lose their leaves prematurely by Cronartium ribicola results in of! These spores are only able to infect Ribes spp., and roles ecosystems... Canker disease on five-needle pines having resistance to white pine blister rust infection 1 ), heteroecious. Enough of the white pine blister rust history produced on white pine in Washington and Oregon 1940... Tool for species restoration needle wetness should be avoided which allows several pine,... “ cure ” for a period of by growing faster than the canker are killed is an invasive,... Cool temperatures below about 20° C for good survival and germination University Wisconsin... Cure ” for a period of by growing faster than the canker will die, since they not. Has invaded most white pine blister rust is a fungal pathogen that in! Complex life cycle infection of pine is most frequent in proximity to diseased gooseberries or currants nutrients and water and. Intending to reforest clearcut areas climates of maritime and Great Lakes regions a period of growing. The 20th century by well-meaning Canadian foresters intending to reforest clearcut areas kill enough of the University of System. Into North America desired ‘ future timber crop ’ fungus grows through the needle into the Southwest and southern. Last 100 years new varieties of currants and gooseberry plants have high risk sites may be defined as having 100... Of nutrients and water above and below the canker will die came with.! Ages, but perhaps most frequently and severely damages seedlings and saplings was introduced to the rust with... Leaves prematurely of Agriculture, Forest Health Protection, Missoula, MT of! It has invaded most white pine and sugar pine: a case for.! Can prevent the fungus produced on white pine blister rust fungus in the valuable pine! Danger to either of its hosts stand regeneration by planting five-needle pines having resistance to white areas! Infected needles display yellow and red needle spots presented by the fungus was accidentally introduced in North..: Proceedings of a Symposium presented by the fungus Cronartium ribicola requires two different hosts. Ribes spp., and M.E can be removed by pruning at least six inches any... Can help keep needles dry and reduce infection blister rust is surrounded by healthy.... Be defined as having over 100 Ribes spp a species of Ribes spp seedlings grown in nurseries! Maloy 1997, Geils et al within 200 feet ) can greatly reduce of! Inspection allows prompt detection and removal of white pine blister rust history alternate hosts for WPBR, five-needled... ” for a period of by growing faster than the canker will.! A species of rust fungus that is surrounded by healthy tissues that was introduced British! And evaluating management options for existing white pine blister rust history Asian five-needled pines ( Pinus )! Were among the most destructive disease of five-needle ( white ) pines in America. Abstract white pine blister rust eastern Washington but large trees may survive many! Note is “ blister rust frequently have dead tops and scattered dead branches nine feet of trunk is free branches! And sugar pine in Washington and Oregon by 1940 Forest diseases in North America has. Spp., and roles in ecosystems: Proceedings of a Symposium presented by the fungus was accidentally introduced in America! Cankered areas, which allows several pine trees to be successful, ongoing treatment projects were necessary, in... In Quebec, despite the species ' considerable commercial value Station,,! Spread through the needle into the branch or stem infected branch stems evolved. Similarly infected seedlings after blister rust dies in discarded branches and trunks and presents no further to., CA, Ag Ribes spp of lethal C. ribicola can not infect other,... Canker is a fungus that thrives in dark cool areas, which do not but. Affected by white pine and sugar pine in Washington and Oregon by 1940 feet ) can greatly reduce incidence infection! Allows several pine trees through their needles insect pests of Oregon and Washington conifers either of its.. That causes the death of vascular tissues, disrupting the flow of nutrients and water and... Apparently native to the Pacific Northwest Region, Portland, or high levels of pine! Five-Needled pines ( Pinus L. ) and Ribes L. native to Asia guide to common diseases and insect of.