RELATION OF SIZE OF SEED AND SPROUT 
VALUE TO THE YIELD OF SMALL 
GRAIN CROPS 
T. A. KIESSELBACH AND C. A. HELM 
RESERVE FOOD OF SEEDS 
The food consumed by seed-producing crops in their initial 
growth during germination and prior to their independent 
existence originates in the reserve food stored either in the 
endosperm of the seed or in the cotyledons of the embryo plant 
within the seed. This reserve food is liberated by enzymatic 
action in the process of germination. When the roots have 
become established in the soil and the chlorophyll-bearing foliage 
has commenced development above the ground, the seedling is 
enabled to obtain necessary plant food material independent of 
reserve food within the seed. Under any conditions, the seed- 
lings may continue to draw upon the store of reserve food until 
the supply has become exhausted and merely the nonavailable 
seed residue remains. 
The actual amount of reserve food is indicated approximately 
by the difference in weight of the dry matter of the original seed 
planted and of the inert seed residues after the seedling has 
extracted all of the reserve food. 
During growth, a portion of this reserve food enters into the 
plant substance of the seedling. Another portion is lost alto- 
gether from the plant during respiration in which carbon, oxygen, 
and hydrogen are liberated according to the following formula: 
C6H12O6+ 6 O2 = 6 CO2+ 6 H2O. These two sources of loss in 
weight of seed substance upon germination comprise the chief 
disposition of the reserve food content of seeds. Other sources 
of loss are probably quite negligible. 
Duggar (1911) states that ''seeds which germinate rapidly 
may lose, under favorable conditions, one-third of their dry 
weight (by respiration) during a period of 10 days, which is an 
average of about 3 per cent a day." 
That portion of the reserve food which enters into the seed- 
ling structure is quite accurately measurable, and for various 
grades of seeds is an index of the relative amounts of reserve 
food contents when planted under similar conditions. This por- 
tion is of prime importance in plant growth and represents the 
sprout value of the seeds. 
(9) 
