POTATO BREEDING AND SELECTION. 
29 
Potato tuber-unit progeny record (2d or . . year selection). 
Accession No Tuber-unit No Variety Selected 191... 
Selection made by P. O. address 
Selected unit yielded tubers, of which were large (weight, lbs oz.); were 
small (weight, lbs oz.). 
Selected tubers planted, , 191 .. . Character of soil 
3 
C o 
J 
Sprouts. 
Plants. 
Tubers. 
u 
i 
a 
5 
11 
HP 
2 8 
fits 
a 
Weight. 
a 
3 
i-H CO 
a 
GO . 
Weight. 
Total. 
'5? 
M 
-d 
1 
'3 
I 
ft 
ft 
3 
o 
ft 
I 
O 
§ 
ft 
© 
O 
a 
1 
ft 
o 
6 
| 
• 
1 
i 
! 
1 
Total... 
! 
Aver- J 
age . . ! 

! 
General obscrvations.- 
DEPARTMENTAL INVESTIGATIONS. 
During the season of 1911 rather extensive studies were undertaken 
by the Office of Horticultural Investigations and the Arlington 
Experimental Farm (now the Office of Horticultural and Pomological 
Investigations), looking toward the standardization of a considerable 
varietal collection by the tuber-unit method. This work was carried 
on at Honeoye Falls, N. Y. Hill selections were also made the same 
season in a field of Irish Cobblers near Portsmouth, Va. 
TUBER-UNIT STUDIES. 
In 1911 some 150 standard commercial varieties of potatoes 
were planted on the tuber-unit basis (PL XIV), in order that their 
purity and uniformity in size and type might be more closely studied. 
The seed used was grown in Burlington, Vt., in 1910, on land which 
had not grown a cultivated crop of any kind for at least 35 years. 
In addition to this, the seed was selected from the most promising 
hills at the time the crop was harvested. The tubers as a whole 
