Received for publication May 24, 1974. Published with the approval of the Director of the Hawaii Agricultural Experiment Station as Journal Series No. 1761. From a dissertation submitted by the senior author in partial fulfillment of the requirements for the Ph.D degree at the University of Hawaii.
Present address: P. B. Division, NIFOR, Benin City, Nigeria, N. A.
Professor and Horticulturist, Department of Horticulture.