Abscission of Flowers and Fruits of the Apple 



lOI 



figures that the short -stemmed fruits, which are developed from the 

 central flower on the spurs, can set with fewer seeds than are needed for 

 long-stemmed fruits which are developed from lateral flowers. 



Seed content and weights of long-stemmed and of short-stemmed fruits pro- 

 duced on the same spur 



Casual observations indicated that frequently the weights of fruits 

 borne on the same spur were not in proportion to their seed content; in 

 many cases the fruits were of the same size altho the seed niunber varied, 

 and in not a few cases the fruits with the smaller number of seeds were 

 larger than the fruits with the greater mmiber of seeds. Further study 

 showed that the fruits which attained the larger size with the fewer seeds 

 were the short-stemmed fruits. Representative data are given in table 50: 



TABLE 50. Seed Content and Weights of Long-stemmed and of Short- 

 stemmed Fruits Borne on the Same Spur 



As has been mentioned, the short-stemmed fruit develops from the 

 central flower, which is the first to open in spring. These flowers would 

 probably be pollinated before the others, and it is possible that priority 

 of pollination may be an advantage in causing a set with fewer seeds. 



The short stems frequently become clubbed, or fleshy (fig. 8). The cen- 

 tral fruits are obviously in the most desirable position from the stand- 

 point of sap supply. The fact that short-stemmed fruits can attain a 

 larger size with fewer seeds than long-stemmed fruits on the same spur, 

 lends further support to the theory that abundant sap flow is essential 

 for fruit setting. Seeds are of value since they stimulate sap flow, but 

 the size of the conducting tissue leading to the fruit is of considerable 

 importance as well. This fact also emphasizes the importance of having 



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