Received for publication May 11, 1976. Journal paper no. 6236 of the Purdue University Agricultural Experiment Station.
Graduate Research Assistant and Professor of Horticulture, respectively. The authors gratefully acknowledge the contributions of Drs. H. J. Brooks, W. A. Oitto, R. C. Blake, Mr. Wayne Zook, and other persons involved in the USD A pear breeding program, and of Dr. R. E. Cooper and Ms. Rosemary Guthrie of the Numerical Analysis Branch of Data Systems Application Division, USDA-ARS, Beltsville, Maryland for assistance in computer analysis.
Research Plant Physiologist and Research Plant Pathologist, respectively.