Seedling mortality can be caused by root pruning. Pine Seedling Survival Increased by Machine Planting Large Seedlings David South and Bob Mitchell F or several decades, AAES researchers have been trying to improve the survival of pine seedlings. Several important factors have been identified, including proper nursery management practices, good planting supervision, and sufficient soil moisture at time of planting. Two very important factors are seedling size and planting method. Research has shown that seedling survival can be significantly improved by machine-planting larger seedlings.
Larger seedlings survive better because they have more roots.
Seedlings with more fibrous roots can quickly produce new roots soon after planting. This ability is related to a seedling's root growth potential, which is a measure of the new root growth under controlled conditions. Theoretically, seedlings that can produce many new roots within four weeks of planting will survive better than seedlings that produce only a few new roots. Some researchers believe that seedling morphology has little to do with the ability of a seedling to quickly produce new roots. However, AAES studies have demonstrated a positive correlation between root mass and root growth potential.