20 
BULLETIN 958, TJ. S. DEPARTMENT OF AGRICULTURE. 
produced at the base of the stem, with a gradual increase in length 
in the upper positions. Since only one variety was included in this 
phase of the experiment, further studies with other varieties are 
necessary to determine the general applicability of these results. 
With respect to the size of the tuber, the greatest average weight 
was produced by the lowest stolons in the 2-stolon and 3-stolon 
groups; while in the 4-stolon group the maximum production, was in 
the second position, with a gradual decrease in the weight in the upper 
stolons. Larger numbers of observations, however, are needed to 
establish the laws governing these relationships. 
SIZE AND CHARACTER OF SEED PIECES AS RELATED TO TUBER PRODUCTION. 
Experiments were conducted to determine to what extent tuber 
production is influenced by the size of the seed piece; also to deter- 
mine the relative influence of whole and cut seed. The tubers used 
for these studies consisted of 1, 2, 3, 4, 5, and 6 ounce sizes of. the 
Rural New Yorker variety. One lot was planted whole, another 
cut in halves, and the remaining lot quartered. The hills were 16 
inches apart in the row, with rows 36 inches apart. The series was 
duplicated and the work relating to the problem under discussion 
carried on for two years, 1916 and 1917. 
Since the results of these experiments will be published in detail 
in another report, only a brief summary, which includes the averages 
of such data as bear directly on this question for the two years, 
will be given at this time (Tables VII and VIII). 3 ' 
Table VII. — Relation of the size and kind of seed piece to the number and weight of tubers 
per hill and per stem as shovm in tests of the Rural New YbrJcer variety of potatoes grovm 
atGreeley, Colo., in 1916 and 1917. - - .. . , 
Weight 
_ of seed 
piece 
planted 
(ounces). 
Number 
of steins 
per hill. 
Number of tubers. 
Weight of tubers 
(grams). 
Size of tubers. 
Per.hill.. 
- 
Per stem. 
Per hill. 
Per stem. 
Planted whole:. 
1 
2 
3 
4 
•5 
6 
1 
H 
2 
2i 
3 
f 
1 
n 
n 
1.76 
2. 60 
3.22 
3.72 
.4.51 
5.03 
1.81 
2.25 
2.50 
2.63 
3.05 
1.49 
1.63 
1.85 
1.96 
4.25 
.. 6.31 
. 7.18. 
7.96 
. 9. 22 
10.11 
3. 99 
2.41 
. 2.42 
.2. 23 
2.14 
. 2.04 
2.01 
2.20 
.712.72 
876.55 
886.23. 
952. 92 
. 986..59 
1,030.31 
668. 61 
. 764. 90 
815.51 
785. 78 
. 836/54 
663784" 
673.25 
724.84 
737.56 
...404.80 
- 336.74 
. 274.85 
• 255.86 
. 218.65 
6 ounces 
Tubers cut in halves: 
2 ounces 
/ 204.70 
368.89 
4.79 .2.12 
339.32 
5.29 
5.61 
6.28 
3.35 
3.63 
3.94 
4.13 
2.12 
2.13 
2.06 
2: 25 
2.23 
2.13 
in 
326.65 
• 298.45 
274.14 
Tubers cut In quarters: 
3 ounces 
— " 444.84 
413.20 
5 ounces : 
6 ounces 
390. 91 
375. 95 
3 The calculations of the data used in these tables are based on the total number of individuals for 1916 
and 1917 rather than the average for the two years, so that they give the true averages for the entire period 
of the experiment. 
