Status of fusiform rust incidence in slash and loblolly pine plantations in the southeastern United StatesThis article is part of a larger document. View the larger document here.
Southern pine tree improvement programs have been in operation in the southeastern United States since the 1950s. Their goal has been to improve volume growth, tree form, disease resistance, and wood quality in southern pines, particularly slash pine (Pinus elliottii) and loblolly pine (P. taeda). The disease of focus has been fusiform rust, which is caused by the fungus Cronartium quercum f. sp. fusiforme. Prior to the 1930s, fusiform rust existed at endemic levels across the region, but following changes in forest management practices during the 1950s and 1960s, the disease increased to epidemic proportions. Since the 1970s, rustresistant planting stock has been developed and increasingly deployed throughout the southeastern United States. Analysis of data collected by the Forest Inventory and Analysis Program of the Forest Service, U.S. Department of Agriculture showed that current rust incidence is generally higher in slash pine plantations than loblolly pine plantations and that, during the past 30 to 40 years, declines in rust incidence were evident in young (i.e., 5 to 15 years old) planted loblolly pine stands but not in young planted slash pine stands.