By Renae Moran, Tree Fruit Specialist, University of Maine Cooperative Extension For information about UMaine Extension programs and resources, visit extension.umaine.edu.Find more of our publications and books at extension.umaine.edu/publications/. Table of Contents: Expected Yield Estimated Production Costs Selecting Varieties Table 1. Important traits of Japanese plum (Prunus salicina) varieties, listed in order of ripening. Table