Received for publication June 6, 1974. Scientific Article A1998 Contribution No. 4940 of the MD Agricultural Experiment Station, Department of Horticulture.
Research conducted in partial fulfillment for the degree of Doctor of Philosophy at the University of Maryland. Present address, Department of Horticulture, University of Arkansas, Fayetteville.
The authors express appreciation to Robert Howell and the Plant Air Pollution Laboratory, USDA, Beltsville, MD, for fumigation facilities: Yoder Brothers, Inc., Barberton, OH, for cuttings; Pennwalt Corp., Tacoma, WA, for thiophanate ethyl; Elanco Products Co., Indianapolis, IN, for trianimol and E. J. Koch, USDA Biometrics Division, Beltsville, MD, for assistance with the statistical analysis.