THE IDENTIFICATION OF PLUM VARIETIES FROM 

 NON-BEARING TREES 



By Lawrence Southwick, Research Assistant in Pomology, 

 and A. P. French, Professor of Pomology^ 



This bulletin is the fifth in a series on the identification of fruit varieties from 

 nursery and non-bearing trees. Papers relating to apples and cherries have been 

 published (2) (4) (5) (6). 



Although it is true that apples and cherries have been mixed in commercial 

 nurseries rather more generally than plums, yet in the experience of the authors, 

 mixtures in plums are not infrequently observed. This has led in recent years, 

 in most nurseries visited, to as careful annual inspection of plums in the nursery 

 row as of apples and cherries. Not only have mixtures been found in the old 

 standard sorts, but in some cases varieties recently named and introduced have 

 been found misnamed in their entirety or mixed with other varieties. Hence, 

 the need is apparent for information which ma\' help to eliminate such mixtures. 

 This bulletin records in words and pictures much of the information necessary 

 to distinguish plum varieties from one another. The list of varieties included 

 in this study is not complete by any means, but a majority of the plums now 

 found in commercial nurseries are included as well as some less known old varieties 

 and a number of the newer ones. 



Previous publications dealing with varietal differences of plum varieties as 

 nursery trees are few. Upshall (8) has briefly described some of the more impor- 

 tant varieties. Shoemaker (7) has made some further comparisons using shoots 

 from bearing trees. 



It should be stressed here that the characteristics of nursery trees cannot be 

 learned satisfactorily from printed descriptions or even pictures. Much time 

 must be spent in close observation of nursery trees that are known to be true to 

 to name before one can positively identify varieties and accurateh' separate 

 mixtures in the nursery row. This bulletin should aid materially in the acqui- 

 sition of such a working knowledge. 



All of the descriptions and pictures in this bulletin were derived from one- and 

 two-year budded trees growing in the Experiment Station nurseries at Amherst. 

 In a few cases, only one-year trees were available. Every effort was made to 

 establish the identity of each variety used in this study. The sources of bud- 

 wood include the New York State Agricultural Experiment Station at Geneva, 

 the Minnesota Agricultural Experiment Station at St. Paul, the Ontario Horti- 

 cultural Experiment Station at Vineland, and our own bearing trees at Amherst. 



Confusion of Names Among Plum Varieties 



PRUNES 



Hedrick (3) mentions several strains of German Prune, two of which (the 

 Rochester strain and the Dansville strain) he suggests are more or less frequently 

 found in the nurseries of New York State. The German Prune herein considered 

 is the same as that described by him as the Rochester strain and is the common 

 German Prune of the nursery trade. In the opinion of the writers, the Dansville 

 strain of German Prune (fruit of which Hedrick was unable to obtain) was nothing 

 more or less than Italian Prune. Some years ago several lots of "German Prune" 



'The writers are indebted to Dr. J. K. Shaw for much valuable counsel both in the field work 

 and in the preparation of the manuscript, and to Professor O. C. Roberts for assistance in ob- 

 taining the field data. 



