Abscission of Flowers and Fruits of the Apple 



71 



relation between weight of the spur and length of the previous 



season's growth 



Data are presented in tables 18 and 19 (pages 65 and 66) indicating 

 that spurs making a relatively short growth during the season previous 

 to the one in which they bear flowers are less likely to set fruit than spurs 

 making a longer growth. Is there any relation between such length growth 

 and the weight of the new spur growth arising from the terminal bud ? 



In a study of this question the flower-bearing spurs from several Bald- 

 win limbs were divided into two lots. One lot consisted of spurs from 

 buds terminating more than one centimeter of 19 15 growth; in the other 

 lot, the spurs were from buds terminating less than one centimeter of 

 19 1 5 growth. The total weight of each lot and the average weight of 

 the spurs are given in table 26: 



TABLE 26. Relation between Weight of the Spur and Length of the 



Previous Season's Growth 



The figures indicate that spurs making a relatively long growth during 

 the preceding year will produce heavier and more vigorous buds in the 

 following year than those making a short growth. That the spurs arising 

 from buds terminating several centimeters of a given season's growth 

 are more vigorous than spurs arising from buds on short spur-growth, 

 may be observed even before the individual flower buds open (fig. 3). 



It should not be assumed, however, that vigorous buds are produced 

 only on relatively long growth and that spurs making a short growth 

 are always weak. Cases in which the reverse conditions obtain are occa- 

 sionally found. Nevertheless, the length of spur growth produced during 

 the previous season forms a very convenient and satisfactory guide to 

 the vigor of a spur, and the best criterion for a probable set is found in 

 this character. 



185 



