10 Nebraska Agricultural Exp. Station, Research Bui. 11 
A superior yielding power has frequently been attributed to 
the extra large seed. Since the seeds of any given crop com- 
monly differ markedly in size, it is of importance from the stand- 
point of crop production to know the extent to which this differ- 
ence in size may affect the yield of the crop produced. The 
following experiments have been conducted for the purpose of 
contributing further to the information upon this subject. 
SPROUT VALUE OF DIFFERENT GRADES OF SEED 
The sprout value is the moisture-free weight of the 
maximum plant growth derived from the seed when planted and 
grown in a nonnutritive quartz medium and in absolute dark- 
ness. Under these conditions no photosynthesis or intake of 
soil solutes is possible, and the moisture-free substance of the 
seedling is derived from the reserve food material of the seed. 
In these experiments the sprout value of seeds was determined 
as follows: The seeds were grown to their maximum develop- 
ment in a pure quartz medium, in absolute darkness, at a tem- 
perature of 30° C, and watered only with distilled water. Max- 
imum development was regarded to have taken place when 
further growth was not apparent and the seedling commenced 
deterioration. When this stage of development was reached, the 
entire seedling (including the roots) was very carefully washed 
from the sand in running water. All growth external to the seed 
was separated from the seed residue and the root growth and 
stem growth divided. The three portions were weighed sepa- 
rately after being rendered moisture-free by drying in an electric 
oven at 110° C. Since no substance may have been added to 
the seedlings either by intake of soil solutes or by photosynthesis, 
the weight of the root and stem growth together with the loss 
thru respiration, minus the inert seed residue, should represent the 
total available reserve food in the seeds tested. 
RELATIVE SPROUT VALUES OF DIFFERENT GRADES OF SEED WHEAT 
The relative sprout values of various grades of winter and 
spring wheat were determined according to the method previously 
described. The grades designated as large plump, small plump, 
large shrivelled, small shrivelled, large, small, and medium, were all 
selected by hand from original seed as secured from the threshing 
machine. In 1913, seed selected in the milk and dough stage 
from the growing crop were also included. 
A chemical analysis was made of the various grades of wheat 
tested in 1913, and the composition is given in table 1. It is 
evident from the relative weights of the seed and the composition 
that distinct grades were employed. 
