Equal volumes of peanut hulls, pine bark, and sphagnum peatmoss were combined into 5 media. Particle size distribution, total porosity, air space, easily available water, water buffering capacity, and bulk density were determined for each medium. Top dry weight, root dry weight, and percent growth of Rhododendron indicum (L.) Sweet cv. George L. Taber were measured 14 weeks after potting in 1-liter containers. Peanut hulls increased particle size, total porosity, and air space, and decreased easily available water, water buffering capacity, and bulk density of media. Peatmoss generally reduced total porosity and air space and increased easily available water, water buffering capacity, and bulk density regardless of other component combinations. Top dry weight, root dry weight, and percent growth were greater in peanut hull-containing media. Addition of peatmoss to the container media tended to produce less growth.
Received for publication Sept. 2, 1981. Paper No. 7063 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC.
The use of trade names does not imply endorsement by the North Carolina Agricultural Research Service of the products named or criticism of similar ones not mentioned. Partially funded by a grant from the Fred C. Gloeckner Foundation, Inc. The authors wish to express appreciation to Harold Lee, Fairview Nursery, Wilson, N.C., for contribution of peanut hulls, Kamlar Corporation, Rocky Mount, N.C. for contribution of pine bark, and Sierra Chemical Company, Milpitas, Calif, for contribution of Osmocote.
The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.
Assistant Professors, Department of Horticultural Science.
Special Student, Present address: Johnson Nursery, Route 2, Willard, NC 28478.