Investigation of Root Growth Potential(RGP) in Bare Root and Container Seedlings of Loblolly Pine(Pinus taeda)

Root growth potential(RGP) is the ability of a seedling to produce new roots (white roots) in a defined period and under defined conditions. Pinus taeda is one of the most important conifers, planted in Guilan province in an extensive scale. Therefore a study of its characteristics, specially RGP has a great positive effect on the production of its seedlings in nursery. The experimental design used is a complete randomized design(RCD) with 6. treatments and 5 replicates. Results indicated that a bare
root seedlings under fertilizer treatment conditions had highest value for RGP. Container seedlings developed a greater amount of root and were superior in some other variables studied, but the root system was strongly twisted. Root pruning was demonstrated to have nosignificant effect on root growth potential.