-Butternut canker, caused by the fungus Sirococcus clavigignenti-juglandacearum, is killing butternut (Juglans cinerea) throughout its range in North America. First report from Wisconsin in 1967, the disease has killed up to 80 percent of the butternut in some states. The primary hope for biological control rests with genetic selections. Healthy trees, and infected trees that apparently have resistance and survived the disease, have been found in severely affected forest stands in 19 states. Clonal and seedling propagation of trees exhibiting resistance is being used to evaluate breeding and future restoration efforts. Hybrids are also being evaluated as an alternative biological control technique. A number of trees have been observed recovering from butternut canker. This pattern or major loss of tree followed by recovery of the remaining trees is typical of hypovirulent fungal strains and needs exploration.

Butternut (also called White Walnut and oilnut) is a small to medium size tree that matures around 75 years of age, is shade intolerant and reproduces by sprouting or seed germination. It grows on rich loamy soils, as well as, drier rocky soils. Butternut typically is mixed with other hardwoods such as black walnut. The species is found in New England, south to Northern Georgia, in the United States from west to central Missouri and north to the Lake State (Distribution Map). It hybridizes with other species of Juglans such as heartnut, Japanese walnut, English Walnut, little walnut, and manchurian walnut.

Butternut is valued for its wood for furniture, paneling, specialty products, carving, and nut production. It is second in value only to black walnut. Although walnut is not commonly found growing together in great numbers, there is concern to maintain a viable butternut population to preserve biodiversity.