From lifting to planting: Root dip treatments affect survival of loblolly pine (Pinus taeda)

Abstract

Hydrogels and clay slurries are the materials most commonly applied to roots of pines in the southern United States. Most nursery managers believe such applications offer a form of "insurance" against excessive exposure during planting. The objective of this study was to examine the ability of root dip treatments to: (1) support fungal growth; and (2) protect roots from injury during exposure for 1, 2, or 4 hours. Four treatments were tested: kaolin clay, two grades of polyacrylamide hydrogels, and a cornstarch-based hydrogel. In laboratory tests, kaolin clay was the only treatment that inhibited the growth of three soilborne fungi (Pythium spp., Fusarium spp., Rhizoctonia spp.). When applied to roots, however, the clay slurry did not effectively prevent permanent root damage during exposure of more than 1 hour. Gel treatment provided some protection when roots were exposed to air for 2 or 4 hours. Current use of root gels is still good "insurance" against poor handling of the seedlings after they leave the nursery.

Parent Publication

• National Proceedings: Forest and Conservation Nursery Associations-2008

Citation

Starkey, Tom E.; South, David B. 2009. From lifting to planting: Root dip treatments affect survival of loblolly pine (Pinus taeda). In: Dumroese, R. K.; Riley, L. E., tech. coords. National Proceedings: Forest and Conservation Nursery Associations-2008. Proc. RMRS-P-58. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 90-94