Mar. 24,1923 
Permanence of Variety in the Potato. 
95i 
hardly have been due to inherent difference in vigor from the other lots, 
since in 1917 and 1918 the yield of this lot was fully equal to that ob¬ 
tained from the other lots. In 1920 another lot designated as No. 9 was 
obtained and was grown in comparison with lots 2 and 7 at Grand Rapids. 
It gave an intermediate yield between these two lots. 
The results of the 4-year test show no significant difference between 
the lots. They indicate that a significant difference probably did not 
exist. It is evident that the selected seed stocks 2 and 9 were not superior 
in vigor to the unselected seed stocks. 
Table I. —Productivity of Early Ohio Lots at University Farm , Duluth , Grand Rapids , 
and Crookston in 1917, 1918 , 1920 
I, 
lot 
No. 
2 
3 
4 
6 
7 
8 
9 
1 Obtained in 1919. 
The effect of seasonal conditions on the yield of the progeny is of 
interest. In Table II is shown the yield of the same seed stocks in 
1917, at Duluth, Grand Rapids, and Crookston, and their subsequent 
yield in 1918 at University Farm, Duluth, Grand Rapids, and Crookston. 
The yield is that of a 4-rod row plot computed to bushels per acre. Col¬ 
umn III shows that all lots gave a very low yield at Crookston in 1917 
in comparison to the yield obtained at Grand Rapids, and that a yield 
intermediate between that obtained at these two places was obtained 
at Duluth. Columns IV, V, VI, and VIII show the results obtained in 
1918 in tests at University Farm, Duluth, Grand Rapids, and Crook¬ 
ston of the different portions of the lots grown at Duluth, Grand Rapids, 
and Crookston in 1917. The results given show that the excessive 
rainfall and an early frost which caused the low yield at Crookston in 
1917 and made the tubers appear worthless for seed stock had no effect 
on their yielding ability in 1918. 
EFFECT ON FORM OF TUBER 
Of the various tuber characters that are usually collectively designated 
as type, that of form is one of the most important. Representative 
tubers of some of the original seed stocks are shown in Plate 1. Lot 2, 
obtained from Anoka, Minn., was oval in shape, being short and broad 
(PI. 1, A). Continuous selection had been practiced by the grower 
toward this form of tuber, which is representative of the type obtained 
on the sandy loam soil of the region in which it was grown. Lot 3 was ob¬ 
tained from the North Central Experiment Station, Grand Rapids. The 
II, source of seed, 1916. 
Ill, yield, 1917. 
IV, yield, 1918. 
V, yield, 1919. 
VI, 
yield, 
1920. 
University 
Farm. 
Duluth. 
Grand 
Rapids. 
Crookston. 
University 
Farm. j 
Duluth. 
Grand 
Rapids. 
Crookston. 
University 
Farm. 
Duluth. j 
Grand 
Rapids. 
Grand 
I Rapids. 
Anoka. 
205 
183 
216 
269 
261 
259 
203 
174 
i 74 
219 
202 
179 
326 
318 
3 11 
3 i 4 
316 
265 
44 
63 
80 
75 
7 i 
56 
255 
243 
272 
299 
248 
258 
158 
286 
206 
245 
323 
IS© 
Grand Rapids. 
240 
Faribault. 
185 
164 
156 
Duluth. 
266 
297 
298 
268 
241 
228 
208 
197 
217 
300 
208 
249 
Glyndon. 
197 
130 
Hawley. 
Hopkins 1 . 
147 
