The Effect of Drought on Growth Decline of Loblolly Pine on Littleleaf Sites. J. C. Jacobi, Research Assistant, Department of Forestry, Clemson University, Clemson, SC 29634-1003. F. H. Tainter, and S. W. Oak. Professor, Department of Forestry, Clemson University, Clemson, SC 29634-1003, and Plant Pathologist, USDA Forest Service, Southern Region, Forest Pest Management, Asheville, NC 28804. Plant Dis. 72:294-297. Accepted for publication 6 October 1987. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1988. DOI: 10.1094/PD-72-0294.

Loblolly pine is the recommended alternative for shortleaf pine on high-risk littleleaf sites, yet it suffers from a decline resembling littleleaf disease on these sites. Analysis of radial growth data collected from 17 loblolly pine stands near Union, SC, showed that severe droughts during 1951, 1954, 1956, 1970, and 1980 and a less severe but prolonged drought during 1962–1964 reduced radial growth of all trees. Growth decline of trees with declining crowns started in 1975 and continued through 1983. The lack of correlation between distinctive short-term climatic events and the initiation of growth decline in 1975 indicates that the decline evident in these loblolly trees was not due to drought and was likely due to the complex of factors causing a disease similar to littleleaf disease in shortleaf pine.