Data from tests of root growth capacity (RGC) of jack pine (Pinusbanksiana Lamb.) and black spruce (Piceamariana (Mill.) B.S.P.) on subsamples of planting stock outplanted on variously prepared sites appropriate to the species in boreal Ontario are examined in relation to field performance. These data were collected from six outplantings per species (two per annum for 3 years) and from further subsamples of the planting stock planted in low-stress nursery plantings. Five kinds of microsite were outplanted: untreated, Bräcke patch bottom, and two kinds of mound. On each site, 600 bare-root trees, either2 + 0 pine or 1.5 + 1.5 spruce, were slit planted during the spring planting season. The RGC data are designated RGC-a (no. of roots < 1 cm), RGC-b(no. of roots > 1 cm), RGC-c (mean aggregate length of roots > 1 cm), and RGC-d (mean mean length of roots > 1 cm). Against these, all available quantifications of performance were examined by correlation analysis. In general, correlation of RGC-d with 3rd-year field performance was much stronger than that of RGC-a, RGC-b, and RGC-c. In particular, the correlation between RGC-d and 3rd-year survival was highly significant (P < 0.01) in both species.
Field Performance of <i>Quercus bicolor</i> Established as Repeatedly Air-Root-Pruned Container and Bareroot Planting Stock
