Resin flow responses to fertilization, wounding and fungal inoculation in loblolly pine (Pinus taeda) in North Carolina

• Published in: Tree physiology Vol. 28; no. 6; pp. 847 - 853
• Main Authors: Knebel, L, Robison, D.J, Wentworth, T.R, Klepzig, K.D
• Format: Journal Article
• Language: English
• Published: Canada 01.06.2008
• Subjects: Animals; blue-stain fungi; boring insects; Coleoptera; Dendroctonus frontalis; fertilizer application; Fertilizers; forest trees; fungal diseases of plants; hypersensitive response; infection; insect pests; North Carolina; Ophiostoma; Ophiostoma minus; Pinus; Pinus taeda; Pinus taeda - drug effects; Pinus taeda - growth & development; Pinus taeda - microbiology; Pinus taeda - parasitology; Plant Diseases - microbiology; Plant Diseases - parasitology; plant pathogenic fungi; plant response; resins; sap flow; tree damage; Trees - drug effects; Trees - growth & development; Trees - microbiology; Trees - parasitology; triple superphosphate; urea; Wounds and Injuries; North Carolina; Southeastern United States; USA, North Carolina
• ISSN: 0829-318X; 1758-4469
• DOI: 10.1093/treephys/28.6.847

Resin flow is the primary means of natural defense against southern pine beetle (Dendroctonus frontalis Zimm.), the most important insect pest of Pinus spp. in the southern United States. As a result, factors affecting resin flow are of interest to researchers and forest managers. We examined the influence of fertilization, artificial wounding and fungal inoculation on resin flow in 6- and 12-year-old stands of loblolly pine (Pinus taeda L.) and determined the extent of that influence within and above the wounded stem area and through time. Fertilization increased constitutive resin flow, but only the younger trees sustained increased resin flow after wounding and inoculation treatments. An induced resin flow response occurred between 1 and 30 days after wounding and inoculation treatments. Wounding with inoculation resulted in greater resin flow than wounding alone, but increasing amounts of inoculum did not increase resin flow. Increased resin flow (relative to controls) lasted for at least 90 days after wounding and inoculation. This increase appeared to be limited to the area of treatment, at least in younger trees. The long-lasting effects of fungal inoculation on resin flow, as well as the response to fertilization, suggest that acquired resistance through induced resin flow aids in decreasing susceptibility of loblolly pine to southern pine beetle.