We thank Sarah Brichford, John Houlihan, Tom Davenport, Judith Gale, and
Melinda Pfeiffer, who either reviewed or participated in the development of this
manuscript. We also acknowledge the assistance of Karl E. Larson, Department
of Agricultural Communications, North Carolina State University, for the design
and layout of this publication.
Thecontentsandviewsin thisguideare thoseoftheauthorsanddonot necessarily
represent the policies or positions of the North Carolina Cooperative Extension
Service, the United States Environmental Protection Agency, nor of any contrib-
utors to its publication. Mention of trade names and commercial products does not
constitute endorsement of their use.