Master of Science (MS)


Plant Pathology and Crop Physiology

Document Type



A decline of loblolly pine (Pinus taeda L.), characterized by expanding areas of declining and dead trees, has become prevalent at Fort Benning, Georgia. A 3 year study was conducted to determine the kinds of fungi, insects, and site disturbances associated with this problem. The insects Dendroctonus terebrans, Hylastes salebrosus, Hylastes tenuis, Pachylobius picivorus and Hylobius pales were significantly more abundant in symptomatic than in asymptomatic loblolly pine plots. These root and lower stem-infesting insects consistently carried the fungi Leptographium terebrantis, L. procerum, and L. serpens. Root sampling revealed high levels of root damage and mortality, staining and infection with Leptographium species. This below-ground damage and mortality preceded the expression of above-ground symptoms, such as short chlorotic needles, sparse crowns, and reduced radial growth. A sequence of interactions among this complex of organisms and abiotic factors is proposed as the cause of ‘loblolly pine decline.’ This study confirms the findings for loblolly pine decline at other geographic locations and validates the Loblolly Pine Decline Risk Map as described by Eckhardt (2003).



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Gordon E. Holcomb