How to identify butternut canker and manage butternut trees. Ophiognomonia clavigignentijuglandacearum wikipedia. Their causes include such a wide range of organisms as fungi, bacteria, mycoplasmas and viruses. Butternut canker is a lethal disease of butternut trees, and has no cure. Butternut canker is a fungus that infects and kills healthy butternut trees juglans cinerea of any size or age. Butternut canker disease the butternut tree is being killed throughout its range by a canker caused by the fungus ophiognomonia clavigignentijuglandacearum, described as a new species in 1979. Both naphthoquinones and bark extracts of juglans species inhibited germination of ocj conidia, depending on the selections of butternut. Forest gene conservation association suite 233, 266 charlotte st. Because buartnut is a hybrid of two other plants, the characteristics of the.
Butternut canker butternut canker, sirococcus clavigignentijuglandacearum, is a fungus infecting nearly all butternuts across the united states. Ophiognomonia clavigignentijuglandacearum ocj is a plant pathogenic fungus that causes canker and branch dieback diseases in the hardwood tree butternut, juglans cinerea. First report of butternut canker caused by sirococcus clavigignentijuglandacearum in new brunswick, canada. In this study, we sequenced the genome of ocj and achieved a high. Before sharing sensitive information online, make sure youre on a. The nuts from butternut trees have become an important crop species, but they.
The fungus is found throughout north america, occurring on up to 91% of butternut trees, and may be threatening. Butternut canker the community network of western north. Nair, kostichka and kuntz is a serious threat to the species. Butternut canker is an infection caused by a fungus ophiognomonia clavigignentijuglandacearum that mainly attacks butternut trees. Butternut canker has spread throughout much of the trees range, reaching canada in 1990. Pdf recent insights into the pandemic disease butternut canker.
Butternut strategies for managing a threatened tree. Although there are no reports of this fungus causing disease outside of north america, it is thought to be an exotic pathogen. A forest managers guide to butternut semantic scholar. It grows vigorously and produces nuts with shells that are easy to crack. A plant canker is a small area of dead tissue, which grows slowly, often over years. In some states, this fungus has contributed to almost an 80% decrease in butternut trees, and is truly threatening the survival of the species. Order or download materials at the purdue extension. The fungus is considered to be an introduced disease to north america, but scientists are unaware of its origins. We dont know where the disease originated, but scientists believe it spread from asia to north america. First report from wisconsin in 1967, the disease has killed up to 80 percent of the butternut in some states. The bark has been removed to show the cankered areas. Butternut canker ophiognomonia clavigignentijuglandacearum young butternut showing established canker. Sirococcus clavigignentijuglandacearum is the cause of butternut canker, which is a lethal stem disease.
This cross section of a butternut tree shows cankers were produced for many years. At first only a few cankers were on the tree and the tree recovered. Butternut canker often kills butternuts quickly, but on occasion. Survival of butternut juglans cinerea throughout its range in the eastern united states and southeastern canada is threatened by butternut canker caused by the fungus sirococcus clavigignentijuglandacearum. Improving disease resistance of butternut juglans cinerea, a. The genome of the butternut canker pathogen, ophiognomonia. Butternut canker can survive on dead trees for up to 2 years, and it is able to kill most trees that it infects. Although the nut is very edible, only a few cultivars have been selected that have desirable nut size and cracking qualities. Conservation and management of butternut trees purdue extension. Canker development on the trunk can girdle the tree, leading to canopy dieback and eventual tree mortality. However, the ecological impact far outweighs the economic impact. Stumps of young butternut trees and saplings are capable of sprouting. Butternut canker, caused by the fungus sirococcus clavigignentijuglandacearum, is killing butternut juglans cinerea throughout its range in north america.
Insects associated with butternut and butternut canker in. If this project is successful the butternut can continue its relatively anonymous, but important, contribution to our biodiversity. The cankers cut off the flow of water and nutrients and can kill an otherwise healthy tree. Management butternut canker is killing the species over its whole range. Although butternut canker can occur on saplings of black walnut juglans nigra, the effects of the disease on this species are minimal. Although butternut is also affected by other insect pests and diseases, scj is the most serious threat to butternuts survival fumier et al. Butternut canker and others diseases of forest and shade. They are often found in deep soil along river banks. It has caused a decline in butternut trees by 80% in ontario. Ocj is a member of the order of diaporthales, which includes many other plant pathogenic species, several of which also infect hardwood tree species.
Response of butternut selections to inoculation with. The severity of the disease has prompted the united states to consider butternut a species at risk. In addition to rain splashed spores, it is thought that the fungus may have spread over long distances to infect widely scattered butternut by insect vectors during surveys in 1995 and 1996 we found several insect species in close association with. This 10page pdf publication describes how butternuts, native hardwood trees related to black walnuts, are threatened by butternut canker disease and have been listed as a species of special concern by the federal government. Sirococcus clavigignentijuglandacearum butternut canker. Butternut canker is a fungal disease of juglans cinerea, the butternut tree also known as white walnut or oilnut. A reliable disease screening technique is needed for detecting juglans cinerea with resistance to butternut canker. While ophiognomonia clavigignentijuglandacearum ocj, the butternut canker fungus, has caused rangewide mortality of butternut trees in north america since its first observation in 1967, the history of its emergence and spread across the united states and canada remains unresolved. It is also known to parasitize other members of the genus juglans on occasion, and very rarely other related trees including hickories.
Joseph obrien, usda forest service, butternut canker is a fungus that infects and kills healthy butternut. This extension note provides information on identifying butternut trees and growing butternut trees from seeds. Spores of the fungus enter the tree and create cankers that are elongated, sunken, often with an inky black center and whitish margin. No control for the fungal disease exists and butternut trees are not resistant to it. The nuts are delicious, but the shells can be difficult to crack. Butternut is a relatively short lived tree species that is at risk of being functionally extirpated from new yorks forest by butternut canker. Description top of page the pycnidia form in a thin, dark brown to black stroma of abundant, septate, branched mycelium beneath the outmost bark layer.
Morphological and molecular methods to identify butternut juglans. Dna markers identify hybrids between butternut juglans. Population structure of the butternut canker fungus. Butternut tree ontario saugeen valley conservation. Genetic evidence that butternut canker was recently. Identification of butternuts and butternut hybrids purdue extension. View and download butternut buthf6v instruction manual online. To view the article, left click the link immediately below. The disease is thought to have originated outside of the u.
Butternut is a threatened fine hardwood throughout its natural range in eastern north america because of the invasion of the exotic fungus, sirococcus clavigignentijuglandacearum nair, kostichka and kuntz, which causes butternut canker. Some cankers are of only minor consequence, but others are ultimately lethal and therefore of major economic importance in agriculture and horticulture. Damage caused by the fungus was first reported in wisconsin in 1967, but it was not until 1979 that the fungus was described the fungus was first reported in quebec in 1990, in ontario in 1991. Butternut canker ontarios invading species awareness program. Retain all butternut trees that have no trunk damage and no more than 50% crown dieback, along with trees that have less than 30% crown dieback and cankers covering less than 20% of their main stem and their buttress roots ostry et al. Chestnut blight, butternut canker, and dutch elm disease. Butternut wood is highly valued for veneer, cabinetry and carving. The hope is that canker resistant butternut trees can be found, propagated and distributed to landowners. Population structure of the butternut canker fungus, ophiognomonia clavigignentijuglandacearum, in north american forests. Butternut is an uncommon but widely distributed species that occurs in central and eastern north america. The pycnidia arise from the eustroma and are glabrous, nonrostrate, innate to erumpent and without a clypeus, globose to flattened. Butternut canker ontarios invading species awareness. Cassens, professor and extension wood products specialist department of forestry and natural resources, purdue university, west lafayette, in 47907 butternut butternut juglans cinenea l.
Results support the suggestion that canker free butternut occasionally found growing among butternut severely affected by butternut canker potentially have disease resistance and may have value for genetic conservation and restoration of the species. Multiple butternut cankers on a butternut tree trunk. This pathogen was first reported in 1967 and is now found throughout the native range of butternut, suggesting that it. Oct 28, 2019 ophiognomonia clavigignentijuglandacearum ocj is a plant pathogenic fungus that causes canker and branch dieback diseases in the hardwood tree butternut, juglans cinerea.
The effects of butternut canker were first noticed in. Pdf population structure of the butternut canker fungus. Unlike american chestnuts and chinkapins castanea spp. Retaining butternut as a component of our forests is important because it provides food for wildlife, increases species diversity and contributes to ecosystem resiliency. Spores of the fungus enter the tree and create cankers that are elongated, sunken. Butternut canker resources national invasive species. Butternut juglans cinerea is seriously threatened by a canker disease caused by sirococcus clavigignentijuglandacearum, a fungus with no known sexual stage.
Butternut trees with crown damage due to causes other than canker should be. It is unclear how long butternut canker disease has existed in north america, but research suggests that ocj has recently emerged as a pathogen of butternut in north america furnier et al. Inhibition of ocj by juglans species bark extracts. Sirococcus clavigignentijuglandacearum is a mitosporic fungus that causes the lethal disease of butternut trees juglans cinerea, butternut canker. All other butternut, including dead butternut and trees of poor vigor, should be cut mobot 2010. Butternut is a member of the walnut family and an important source of nuts and wood. Its in danger of disappearing because of a fungal disease called the butternut canker. Pdf viability of conidia of sirococcus clavigignenti.
Butternut canker, caused by the fungal pathogen sirococcus clavigignentijuglandacearum, is present throughout the range of butternut juglans cinerea and is the primary cause for its decline. Butternut trees are treasures that add grace and beauty to the landscape, but butternut canker disease ruins the appearance of the tree, and it is almost always fatal. Butternut canker disease butternut trees of all ages are killed by sirococcus clavigignentijuglanclacearum scj, a fungus found throughout butternuts range. The fungal pathogen sirococcus clavigignentijuglandacearum apparently was introduced from outside of north america.
A relatively slowgrowing tree, butternut attains a mean height of 12 to 18 m. Improving disease resistance of butternut juglans cinerea. Canker diseases hardwoodsbutternut cankercankers on butternut caused by ophiognomonia old name. Below is a brief account of the impacts of these diseases on their host species, examples of research approaches for disease control, and a prognosis for the future of each species. Butternut canker disease us forest service research. Find out about preventing and treating butternut canker in this article. Butternut canker disease affects butternut trees, and occurs when the s. Butternut canker affects butternuts throughout their natural range much of the eastern us, and has killed up to 80% of the butternut trees in some states. The majority of cankercausing organisms are bound to a unique. In the last 20 years there has been a dramatic decline in the number of butternut in native stands caused to a large extent by the lack of natural.
When you have a canker on the trunk of a butternut tree, there is no chance to save the tree. Free download description this 10page pdf publication describes how butternuts, native hardwood trees related to black walnuts, are threatened by butternut canker disease and have been listed as a species of special concern by the federal government. When you take down the tree, remove all of the debris promptly. Canker mortality impacts and potential reintroduction of resistant trees. To ensure that you grow the best nut producers, choose grafted stock rather than seedlings. The trees are reported to be slow growing and seldom live longer than 75 years.
The effects of butternut canker were first noticed in the late 1960s. Limiting factors and threats butternut canker sirococcus clavigignentijuglandacearum v. As a result, natural resources professionals are working to protect and conserve the trees. A combination of basic and applied research has been directed toward developing. Butternut once considered the hardiest of nut trees, butternuts throughout north america are dying from butternut canker. Butternut canker presents itself as an elongated and sunken canker, with a black, oozing center and white margins. To download this article, right click on the link immediately below and choose save target as. Results support the suggestion that cankerfree butternut occasionally found growing among butternut severely affected by butternut canker potentially have disease resistance and may have value for genetic conservation and restoration of the species. Especially virulent, the spores enter the tree through many pathways, including leaf scars and lenticels on small twigs, and. The causal agent of the disease is a fungus, sirococcus. Butternuts survival is threatened by butternut canker, a disease caused by the exotic fungus sirococcus clavigignentijuglandacearum nair. Butternut canker rachel leisso, montana state university plant sciences and plant pathology brian hudelson, uwmadison plant pathology what is butternut canker. Butternut canker is caused by a fungus sirococcus clavigignentijuglandacearum that infects butternut juglans cinerea through openings such as buds, leaf scars, and insect wounds. The spores can remain alive and able to infect healthy trees for two years or more.
For information on the butternut canker, see the brochure. Butternut is closely related to black walnut juglans nigra, which is not naturally susceptible to the disease. Cankers commonly occur at the base of trees and on exposed buttress roots and can survive and sporulate on dead trees for many years. In this study, we sequenced the genome of ocj and achieved. Butternut is presently being extirpated, as butternut canker disease sirococcus clavigigentijuglandacearum spreads into northern populations. It causes multiple cankers on the main stem, branches and twigs of butternut, juglans cinerea. Butternut canker ophiognomonia clavigignentijuglandacearum december 2014 constanza maass the ophiognomonia clavigignentijuglandacearum is an invasive species of fungus that infects the butternut trees and kills them by penetrating the phloem and progressing into bark and wood tissue. Urban and forest american elm populations have been decimated by dutch elm disease ophiostoma ulmi and o.