Trees of red maple (Acer rubrum L.) were planted into seven container types evaluated for their ability to reduce number of roots deflected by the container wall. Seedlings were grown 70 weeks (production phase) in seven container types to a mean trunk diameter of 3.9 cm (1.5 in) and were transplanted into a sandy soil and grown with frequent or periodic irrigation for 24 weeks (landscape phase). There was no effect of container type on total root mass, trunk diameter or height during the production phase. Total deflected root length was less in low-profile plastic containers, chemical root pruning containers, air root pruning containers (ARPC), and wood boxes than in standard black plastic containers (SBPC). Trees produced in the SBPC had the most horizontally-oriented deflected root length while the ARPC and SBPC had the most vertically-oriented deflected root length. Trees grown in the ARPC had less roots on the inside of the root ball than all other container types. Container type did not influence root and shoot growth, but impacted stem water potential in the first five months after transplanting to the landscape. Trees frequently irrigated during the landscape phase had greater trunk diameter, height, and generated more new root mass than those which were infrequently irrigated.
Florida Agricultural Experiment Station Journal Series No. R-05650. We thank the Griffin Corporation, Valdosta, GA 31601; Hold Em, Inc., West Palm Beach, FL 33415; Lerio Corporation, Mobile, AL 36652; and, Ridge Pallets, Bartow, FL 33830 for assistance.
2Graduate Research Assistant and Professor, respectively.