Research on the Appraisal Techniques for the Early-Stage Characters of Loblolly Pine

The research on the appraisal techniques for the early-stage characters of Loblolly Pine (Pinus taeda L.) was conducted, which included the correlation between seed weight and seedling height, the measurements of seed germination and the plant morphology in the seedling stage, the growth of dominant trees in free pollinated families in descendant seedling stage and the growth of graded seedling used for planting. The results have shown that seed weights have an effect on seedling height growth in the early 80 days or before seedlings reach 15 cm in height, which disappears gradually. The height growth at the fifth year can be predicted according to that in the descendant seedlings stage in the same family. There is not obvious correlation between seedling height and early or late seed germination. The height growth have a positive relationship with numbers of whorled branch when lifted from nursery. There is no significant relationship between terminal bud numbers and graded seedlings. The height and diameter breast height of graded seedling I (predominant seedling) have been maintaining a dominance after the planting of six years, and its stem volume is 14.5% more than that of the average of stand.