A Study of Quality in Potatoes. 



229 



total number of tubers decreased, but the total weight increased. 



It was^readily noticeable that small tubers were much in excess over 



the large ones for those hills in the two-inch plat. In reference to 



small tubers, it should be noted, however, that in the division adopted 



for these studies those tubers were considered small which did not 



exceed four ounces in weight. This limit of weight for a small 



tuber is somewhat high, but it seemed feasible to make the division 



at this weight in 



order to be able 



to render more 



accurate judgment 



as to quality. In 



ordinary com- 



mercial grading, 



the small tubers 



include those of 



about two ounces 



and less. 



It will be noticed 

 that the number 

 and weight of ex- 

 posed tubers for 

 those hills planted 

 two inches deep is 

 high. This is due 

 to the fact that the 

 seed piece was not 

 planted deep 

 enough to permit 

 the tubers to form 

 wholly beneath the 

 soil. As these 

 plants yielded quite 

 abundantly it was 



observed that toward the close of the season the tubers raised 

 the soil, and as this was later washed off by the rains, many 

 tubers which began their growth beneath the surface were 

 rendered exposed. (Fig. 182.) In this connection, it should 

 be noted that inasmuch as tubers are borne at the nodes of the stem 

 beneath the surface of the soil, in the instance of those hills planted 

 two inches deep, there was not enough room between the seed set 

 and the surface for the number of tubers to be borne which the plant 

 was capable of producing. Hence many of them w^ere crowded out 







Fig. 182. — Where seed tuber is planted two to three inches 

 beneath the surface of the soil the growing tubers soon 

 become exposed or subjected to adverse temperature 

 conditions. 



