Received for publication April 12, 1982. Paper No. 8256 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, N.C. Portion of a thesis submitted by the senior author in partial fulfillment for the MS degree, North Carolina State University, Raleigh, June, 1979.
Use of trade names does not imply endorsement by the North Carolina Agricultural Research Service of the products named nor criticism of similar ones not mentioned. The authors wish to express appreciation to Kamlar Corp., Rocky Mount, N.C., for contribution of pine bark.
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Graduate Student, present address: The Ohio State University, 2001 Fyffe Court, Columbus, OH 43210.
Associate Professor, Department of Horticultural Science.