IDENTIFICATION OF BLUEBERRY VARIETIES 

 BY PLANT CHARACTERS 



By John S. Bailey, Assistant Research Professor of Pomology 

 and Arthur P. French, Professor of Pomology 



It is of the utmost importance to the fruit grower to get \arieties true to name. 

 Varietal mixtures and substitutions are a continuing source of economic loss. 

 Therefore, anything which can be done to reduce such losses is a distinct advan- 

 tage to the fruit grower and the horticulturist alike. Shaw and his associates 

 attacked this problem by studying the vegetative characters of nursery fruit 

 trees. They have published a series of bulletins (8, 11, 12, 13, 14, 16, 17) de- 

 scribing nursery trees and pointing out differences by which varieties can be 

 identified in the nurserx . This bulletin, the eighth in this series, covers varieties 

 of the cultivated blueberry. 



The blueberry is a newcomer among cultixated fruits. The first varieties to 

 be introduced were selections from the wild and differed markedly from each 

 other. These selections have been hybridized and some of their progeny intro- 

 duced as new varieties which show less marked differences than did their parents. 

 It seems probable as breeding work progresses and fewer lines are used as parents 

 that the differences between future varieties will become still smaller, while at 

 the same time the number of varieties is increasing. 



Hence, it is the purpose of this bulletin to call attention to those characteristics 

 of blueberry plants which seem to be of value in identification work and to put 

 on record a description of the vegetative characters of all the available varieties 

 of cultivated blueberries, as an aid toward the prevention and elimination of 

 variety mixtures. 



Literature 



Several authors have discussed blueberry varieties (1, 2, 3, 6, 7, 9, 10, 15) but 

 few have gone farther than to say that the bush is tall or short, upright or spread- 

 ing. Beckw ith and Coville (2, 3) were the first to record differences in bush shape. 

 They gave diagrams of bush shapes to call attention to these differences. Darrow 

 and Clark (6) in discussing the three varieties Atlantic, Pemberton, and Burling- 

 ton described the bushes and leaves in greater detail than had been customary. 

 Clark (4) was the first to discuss the use of vegetative characters for identifying 

 varieties. He constructed a simple ke\- to separate varieties into. groups similar 

 in their characteristics. Later, Clark and Gilbert (5) investigated further the 

 reliability of certain characters, such as leaf width, leaf length and width/length 

 ratio, which Clark had previously used. They concluded that "leaves 4-5-6 

 from the tip of lateral branches 8 to 12 inches long exhibit a minimum of variabil- 

 ity and, hence, are suggested as criterion leaves for leaf measurements to be made 

 for the purpose of varietal identification"; also, "that tip angle, base angle, and 

 leaf widthy'length ratio are valuable and relativel}' constant characters." 



