The most serious disease of Juglans cinerea is butternut decline or butternut canker. In the past the causal organism of this disease was thought to be a fungus, Melanconis juglandis; but now this fungus has been associated with secondary infections and the primary causal organism of the disease has been identified as another species of fungus, Sirococcus clavigignenti-juglandacearum. Symptoms of the disease include dying branches and stems. Initially, cankers develop on branches in the lower crown. Spores developing on these dying branches are spread by rainwater to tree stems. Stem cankers develop 1-3 years after branches die. Tree tops killed by stem-girdling cankers do not resprout (19,20). Diseased trees usually die within several years (11,16). The disease is reported to have eliminated butternut from North and South Carolina (1). The disease is also reported to be spreading rapidly in Wisconsin; between 1978 and 1983 the incidence of butternut canker in a young, isolated plantation increased exponentially from 5 percent in 1976 to 76 percent in 1983 (20). By contrast, black walnut seems to be resistant to the disease.
Bunch disease also attacks butternut. Currently, the causal agent is thought to be a mycoplasmalike organism. Symptoms include a yellow witches'broom resulting from sprouting and growth of axillary buds that would normally remain dormant. Infected branches fail to become dormant in the fall and are killed by frost; highly susceptible trees may eventually be killed. Butternut seems to be more susceptible to this disease than black walnut (2,17).
The common grackle has been reported to destroy immature fruit and may be considered a butternut pest when populations are high (14).
Butternut is very susceptible to fire damage, and although the species is generally windfirm, it is subject to frequent storm damage (4).
- Burns, Russell M., and Barbara H. Honkala, technical coordinators. 1990. Silvics of North America: 1. Conifers; 2. Hardwoods. Agriculture Handbook 654 (Supersedes Agriculture Handbook 271,Silvics of Forest Trees of the United States, 1965). U.S. Department of Agriculture, Forest Service, Washington, DC. vol.2, 877 pp. http://www.na.fs.fed.us/spfo/pubs/silvics_manual/table_of_contents.htm
No one has provided updates yet.