SIZE OF POTATO SETS. 
29 
RELATION OF SIZE OF SET TO NUMBER OF STEMS AND TUBERS 
PRODUCED. 
In studying the relation of the size of set to the resultant yields a 
record was made of the number of stems and of tubers for each set 
planted. The data presented in Table 13 give the average number of 
stems and tubers for the various sizes of whole and cut seed used in the 
experiments in Maine and Virginia for the 4-year period from 1915 
to 1918, inclusive. In order to facilitate the study of these data, 
whole, halved, and quartered seed are grouped together. A com- 
parison of the number of stems and of tubers produced from each of 
these groups shows almost without exception that as the size of the 
set planted increases in weight, the number of stems and tubers in- 
creases and that the average number of tubers to the stem decreases. 
Exceptions are to be noted in the average number of tubers to the 
stem from the 3-ounce and 4-ounce quartered tubers in the Maine 
experiment. Further study of these data shows that when sets of 
equal weight were planted the whole tuber produced more stems and 
tubers than did halved sets; similarly, halved sets showed the same 
relation to quartered sets. 
Table 13. — Relation of the size of set to the average number of stems and tubers 
per set and of tubers per stem, in potato experiments at Norfolk, Va., and Presque 
Isle, Me., in stated years. 
Weight 
of set. 
Average number of stems and tubers per set and of tubers per stem. 
Irish Cobbler 
1915 to 1918. 
Green Mountain, Presque 
Isle, Me., 1917 and 
1918. 
Kind of set 
planted. 
Stems per set. 
Tubers 
per set. 
Tubers per stem. 
* 
Norfolk, 
Va. 
Presque 
Isle, 
Me. 
Norfolk, 
Va. 
Presque 
isle, 
Me. 
Norfolk, 
Va. 
Presque 
Isle, 
Me. 
Stems 
per set. 
Tubers 
per set. 
Tubers 
per 
stem. 
Whole: 
2-ounce 
3-ounce 
4-ounce 
Ounces. 
2 
3 
4 
5 
6 
1 
? 
3 
1 
H 
H 
2.78 
3.20 
4.05 
3.88 
5.00 
6.15 
9.26 
10.62 
11.90 
10.13 
11.65 
13.13 
3.33 
3.32 
2.94 
2.61 
2.33 
2.13 
3.17 
3.54 
4.61 
5.15 
5.83 
2.12 
2.21 
2.67 
3.18 
3.08 
1.51 
1.82 
1.83 
1.84 
9.50 
10.09 
11.04 
11.25 
13.55 
5.75 
6.71 
7.57 
8.34 
8.69 
4.92 
5.42 
6.11 
7.19 
3.00 
2.85 
2.39 
2.18 
6-ounce 
Halved: 
2-ounce 
3-ounce 
4-ounce 
5.22 
1.85 
2.21 
2.51 
7.49 
2.54 
3.14 
3.79 
13.77 
6.95 
7.42 
8.31 
15.14 
7.58 
8.61 
9.81 
2.64 
3.76 
3.36 
3.31 
2.02 
2.98 
2.74 
2.59 
2.32 
2.71 
3.04 
2.84 
2.62 
6-ounce 
Quartered: 
3-ounce 
4-ounce 
5-ounce 
6-ounce 
2.92 
1.63 
1.66 
4.39 
2.10 
2.33 
8.S5 
6.12 
6.21 
11.05 
6.09 
6.99 
3.03 
3.75 
3.74 
2.52 
2.90 
3.00 
2.82 
3.25 
2.92 
3.34 
1.95 
2.63 
7.13 
7.56 
3.66 
2.87 
3.85 
In the size-of-seed studies with the Green Mountain varieties the 
average results obtained from, the experiments in 1917 and 1918 
(Table 13) show similar increases in the number of stems and tubers 
from each set according to its weight and whether whole, halved, or 
quartered. There is not, however, as uniform a decrease in the 
number of tubers to the stem as the size of the set increases. There 
is one exception in the case of the average number of stems to the set, 
viz, that between 5-ounce and 6-ounce halved sets. In the case of 
