. H'^ ■'■ :;.•'■ . ■ ■ 



From the general discussion of the group, it appears that there is a renewed 

 interest among fruit growers in planting ne^v orchards on semi-dwarf rootstocks 

 which will produce a smaller tree. 



•■■ • . — «W, D. Weeks 



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POMOLOGICAL RESEARCH 

 -"'■ Ve The Cause of Unfruitfulness in the Beach Plum 



Along the coastal plains of eastern North Amsrica from Virginia to New Bruns- 

 wick there grows a small, native, bushlike plum called the beach plum ( Prunus ^ 

 jg feritima) • This is imdoubtedly the plum vfhich the Pilgrims found growing' in' ' ' 

 abundance when they arrived in America o 



Beach plums grow wild in more or less abundance along the seashore of eastern 

 and s6uthea&teiMt"Massachusetts, The bushes are very abundant on Cape Cod, The 

 fruit is generally small and is extremely variable in ripening season, color, 

 fl3,vor and size. It is used mostly for making Jelly and jam. Beach plum jelly 

 is highly prized by many people. This has led to the development on Cape Cod 

 of an extensive industry for the manufacture and sale of this product, A few sup- 

 erior types of iTild bushes have been selected and named but these are grown on 

 a very limited Scale, OrtLy a very £evT nurseries have named varieties of beach 

 plums for sale and the supply is extremely small. As a resvilt there are only 

 a fevf regular plantings of beach plums and these .are made up mostly of unnamed 

 seedlings transplanted from the wild. ■> '^"tZ • 



The -beach plum has a variety of troubles but from the standpoint of the users 

 of this fruit the v/erst is its failure to bear fruit more than cnce in three or 

 four years iii spite of a generally, heavy annual bloom. The project under dis- 

 cussion is aimed at finding out why" this is so and what can be done about it, 

 A number of factors, each of which probably plays a part, are being studied and 

 considerable progress has been made e Some of these factors are; 



First, self unfruitfulness. It has been recognized for a number of years 

 that most, if npt all, beach plum bushes are self unfruitful. Cross pollination 

 is required to produce a. .crop,., 



Second, biennial bfe^ring, Fiany beach plums are definitely biennial in their 

 bearing habit. Even where they are pruned, fertilized^ sprayed and have adequate 

 cross pcSlination.^ they will produce a crop only. every other years 



Third, clones. Many beach plum seedlings sprout very freely from the roots 

 which grow to considerable distances from the original bush. What appears to be 

 a collection of seedlings is iji reality a clone since all the plants arose from 

 the same bush. Under these conditions crosspollination, which would usually 

 result in fruit production, is not possible. 



