260 DRY-FARMING 
is deeply modified by the arid conditions prevailing 
in dry-farming. This shows itself first in the propor- 
tion of the various plant parts, such as roots, stems, 
leaves, and seeds. The root systems of dry-farm 
crops are generally greatly developed, and it is a com- 
mon observation that in adverse seasons the plants 
that possess the largest and most vigorous roots en- 
dure best the drouth and burning heat. The first 
function of the leaves is to gather materials for the 
building and strengthening of the roots, and only after 
this has been done do the stems lengthen and the 
leaves thicken. Usually, the short season is largely 
gone before the stem and leaf growth begins, and, 
consequently, a somewhat dwarfed appearance is 
characteristic of dry-farm crops. The size of sugar 
beets, potato tubers, and such underground parts 
depends upon the available water and. food supply 
when the plant has established a satisfactory root 
and leaf system. If the water and food are scarce, 
a thin beet results; if abundant, a well-filled’beet may 
result. 
Dry-farming is characterized by a somewhat short 
season. Even if good growing weather prevails, the 
decrease of water in the soil has the effect of hastening 
maturity. The formation of flowers and seed begins, 
therefore, earlier and is completed more quickly under 
arid than under humid conditions. Moreover, and 
resulting probably from the greater abundance of 
materials stored in the root system, the proportion 
