Visual Grading and Quality of 1-0 Northern Red Oak Seedlings
Past research has used detailed measurements of various growth characteristics to determine seedling grades and quality of northern red oak nursery stock This study evaluates the effectiveness ofa visual grading process. similar to thosefound in commercial nursery operations, to distinguish high quality seedlings. Northern red oak (Quercus rubra L.) seedlings were grown for 1 yr at two state nurseries and visually separated into three grades (cull, good, or premium) according to root and shoot characteristics. Approximately 64% of the seedlings grown at each nursery were judged to be of unacceptable size for successful field regeneration. Number of first-order teral roots (FOLR). height, and tvot collar diameter (RCD) were measured for seedlings in the good and premium grades. Premium grade seedlings were significantly larger than the good grade seedlings for both burseries. Phenotypic correlations of growth traits were strongest between number of FOLR and RCD. The qesults demonstrate that high quality nursery stock can be visually selected into two distinguishable grades.