12 STUDIES ON PEACHES. 



In Table II there is given in detail the percentage composition of six 

 varieties of peaches at three stages of their life history a , i. e., the time 

 of the June drop, when the peach is small and very green; the period at 

 which the stone hardened, or two to three weeks later; and the period 

 at which the peaches were market ripe, i. e., well colored but firm. 

 In two cases (Elberta and Smock) the peaches were also examined at 

 a fourth stage, when fully ripe. On account of the difficulty of keep- 

 ing samples on the trees until they became fully ripe the other varie- 

 ties were not examined at this last stage. In addition to the dropping 

 of the peaches, which would normally take place, the orchards were 

 somewhat afflicted with xcab, which increased the tendency of the 

 peaches to drop. It is regretted that samples were not taken between 

 the second and third periods of the life history of the peaches. 



The change in composition between the time of the hardening of the 

 stone and the time of market ripeness is very great, as will be seen by 

 consulting^ Table II. During this period the weight of the peaches 

 increased more than fourfold. The proportion of flesh to stone 

 increased about five times and the composition of the flesh itself went 

 through much greater changes than occurred earlier in the life history 

 of the fruit. The examination of samples at more frequent intervals 

 would indicate more exactly the period in the life history of the peach 

 at which these changes begin and at which they are greatest, and for 

 that reason would be very valuable. The results here given, however, 

 are believed to be of value for the purpose of marking out the bound- 

 aries within which certain changes occur and limiting the field within 

 which further investigations of this nature can be carried on with 

 profit. A comparatively small amount of work will now be required 

 to accumulate the details necessary to make our knowledge of the life 

 history of the peach much more complete than it is at present. 



Between the time of the June drop and the time of market ripeness 

 the peaches increased in weight nearly eight times, from 9.51 to 73.59 

 grams per peach. During the same time the per cent of flesh in the 

 peach increased less than one- half, from 61.55 to 92.49; while the per 

 cent of the stone decreased from 32.5 to 6.86, and that of the kernel 

 from 2.91 to 0.65 per cent. 



The percentage of solids of the flesh b remains fairly constant during 

 the life history of the peach; that is, the increase in solids is fairly 



See pages 10, 11. 



6 In Table II, and wherever else percentages are given in this bulletin, the calcu- 

 lations are made as follows: The percentages of flesh, of stone, and of kernel are 

 based upon the weight of the whole peach. The percentages of solids in flesh, of 

 solids in stone, and of solids in kernel are based upon the weight of the flesh, the 

 stone, and the kernel, respectively. The percentages of the several constituents of 

 the flesh are based upon the weight of the flesh, 



