UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1248 
Washington, D. C. T September 8, 1924 
SIZE OF POTATO SETS: 1 COMPARISONS OF WHOLE AND CUT SEED. 
By William Stuart, P. M. Lombard, Margaret Connor Vosbury, G. 
Corder, W. C. Edmundson, C. F. Clark, and G. W. Dewey, Office of 
Horticultural Investigations, Bureau of Plant Industry. 
CONTENTS. 
Page. 
Introduction- __ .. 1 
Early experimental studies... 2 
Departmental studies of the size of the set... 15 
Experiments at the Virginia Truck Experi- 
ment Station 17 
Studies at Caribou and Presque Isle, Me 19 
Experiments at the Colorado Potato Experi- 
ment Station 24 
Page. 
Ex periments at Jerome, Idaho 26 
Comparative yields from sets of the same 
weight 27 
Relation of size of set to number of stems and 
tubers produced 29 
Frequency correlations of stems 32 
Summary 35 
Literature cited 38 
INTRODUCTION. 
The influence of the size of the potato set upon the resultant crop 
has served as the basis of experimental study through several gen- 
erations and has received a large share of attention from experiment- 
station investigators for more than 30 years, or since the establish- 
ment of these stations. It may seem strange, therefore, that a sub- 
ject to which so much attention has been given should still remain a 
moot question as regards the advisability of planting whole seed or 
of using large tubers when-cut seed is to be planted. Failure to arrive 
at a satisfactory agreement upon the use of whole or cut seed or even 
on the size of the set is attributable to a number of causes, the chief 
of which, it is believed, are the varying influences of temperature, 
moisture, and soil conditions during certain periods in the growth of 
the plant. Other conditions, such as the fertility of the soil and the 
cultural care given to the crop, are also extremely important factors. 
A critical study of the experimental data upon this question im- 
presses one with the idea that in most of the investigations thus far 
reported the work has been performed upon a scale too small to 
justify any sweeping conclusions. In many instances no considera- 
i The term "set" is used in this bulletin in preference to the term "seed piece" because it can be em- 
ployed in a collective sense; that is, it applies equally well to both whole and cut seed. The term 
reason 
"seed piece," if strict adherence to its literal meaning is observed, can only be used for cut seed, 
term "set" being a shorter and more inclusive word is therefore advocated for adoption. Another r 
for its use is that it is almost universally employed by English writers in Great Britain and her colonies. 
85070°— 24f 1 
