A Study of Quality in Potatoes. 



227 



seed set and also to observe the development of the root system. In 

 no instance was a tuber found growing beneath the seed tuber; 

 unless, as in one or two cases, they were forced below by the presence 

 of a stone. Doe's Pride has a tendency to grow somewhat long, 

 sometimes the tubers being two and one-half times their diameter. 

 In instances where the tubers were found growing from two to four 

 inches beneath the surface, they seemed to have a general tendency 

 to grow in a sloping position with the bud end slanting upward 

 (Fig. 178). In many 

 instances in which the 

 tubers were sufficiently 

 long, and the bud end 

 came very near the sur- 

 face there was a differ- 

 ence between the two 

 ends in the physical 

 structure and relation- 

 ship of parts, and con- 

 sequently a difference 

 in the cooking quality 

 (Figs. 179, 180, 181). 

 This fact seems to add 

 evidence to the belief 

 that temperature and 

 moisture conditions in 

 the soil have a marked 

 influence on the quality 

 of the tubers. Whether, 

 however, the difference 

 in quality between the two ends is due wholly to soil-climatic 

 influences cannot be definitely stated, for, as will be shown 

 later, the quality varies with ripeness, and it may be that the bud 

 end of these long and sloping tubers is of later development than the 

 stem end and that the quality difference is one depending upon 

 the degree of maturity and starch development. Whether there 

 is a difference between the starch content of the two ends, is a per- 

 tinent question and one yet to be considered further. Analyses of 

 the ends of three tubers of the present year's crop show starch and 

 protein content as follows:* 



Fig. ISl. — Cross-section from the bud end of the 

 same tuber from which Figs. 179 and 180 were 

 taken. The same treatment wa^ given as to section- 

 ing and boiling. This portion retained its form, 

 even after boiling thirty minutes. Compare Figs. 

 179 and 180. 



* Analyses made by Dr. J. A. Bizzell. 



