14 



MASS. EXPERIMENT STATION BULLETIN 372 



that a comparatively greater strain is placed at the point of contact of the stem 

 and spur than is the case when the stem is long and pendulous. This factor 

 probably plays a significant role in the behavior of different varieties. But it is 

 doubtful if stem length is important in regard to the apples on a single tree, 

 although with young fruits Heinicke (7) found that those with short stems had 

 an advantage. 



Chemical Composition 



Analyses were made of apples which dropped from two trees at intervals of 

 10 days (Table 8). 



Table 8 — Analyses of Apples that Dropped from Two Trees (G-18 and 



F-25) AT Ten-Day Intervals, 1937 



(Computed to Dry Matter Basis) 



Sept. 3 Sept. 13 Sept. 23 Sept. 3 Sept. 13 Sept. 23 



Dry Matter 100 



Ash 2.429 



P2O5 135 



KgO 941 



Na^O 137 



CaO 134 



MgO 112 



Total N 378 



100 



100 



100 



100 



100 



*G-18 samples taken from cold storage in November. 

 F-25 samples taken from cold storage in January. 



The moisture contents approximated 88 to 89 percent leaving 11 to 12 percent 

 of the fruit composition as dry weight. The ash percentages of the apples evi- 

 dently decreased as the season advanced, indicating relative increases in total 

 carbohydrates. Phosphorus and potassium showed decreases while sodium and 

 possibly calcium tended to increase to a slight degree. Such changes could not 

 be considered particularly at variance with those attending normal fruit de- 

 velopment. Hence, no clear indication was found that total ash or its constituents 

 markedly affected dropping. The decrease in total nitrogen may have some 

 significance, especially in consideration of the previous discussion of the relation- 

 ship of nitrogen to drop. 



Effect of Strain 



In recent years there has developed considerable grower reaction in regard to 

 strains of Mcintosh as well as of other varieties. In general, the opinion is 

 favorable to "red bud sports" because of the color advantage. Furthermore, the 



