Loblolly pine seedlings were grown in 1 x 5 inch biodegradable plastic tubes for 10, 12, and 14 weeks at densities of 42, 84, 126, and 168 per square foot. Seedling density and age significantly affected seedling development at time of outplanting, and density became more important as greenhouse growing times increased. All morphological characteristics measured when seedlings were planted-height, diameters, root and shoot dry weights, and proportion of seedlings with secondary needles-were correlated significantly with field survival, height, and growth. Stem dry weights were most closely related to field performance. Best seedling development and performance were obtained at the lowest seedling density.
Barnett, James P. 1980. Density and Age Affect Performance of Containerized Loblolly Pine Seedlings. Res. Note SO-256. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 5 p.