Abstract Bare-root and container-grown loblolly pine ( Pinus taeda ) seedlings with Pisolithus tinctorius (Pt) ectomycorrhizae were planted in microplots containing forest soil. During a 22-week period after planting, seedlings were excavated at 4-week intervals to determine the pattern of lateral root egress and rate of development of Pt ectomycorrhizae on egressed laterals. The pattern for lateral root growth from original root systems differed between bare-root and container-grown seedlings. Bare-root seedlings produced 60 percent more laterals and had significantly more horizontal lateral root egress from the B (middle) horizontal zone of the original root system than container-grown seedlings. Bare-root seedlings also had significantly more Pt ectomycorrhizae on egressed laterals and these mycorrhizae were found at significantly greater distances from the original root system than those on container-grown seedlings after 22 weeks. The implications of these results on field performance of seedlings are discussed. Forest Sci. 31:220-225.
John L. Ruehle (Fri,) studied this question.