The new era. (Walden, Colo.) 1906-19??, 1911-09-14
GRAIN. SORGHUM CROP
Two Ways by Which 1t Can Be
Made of Greater Value.
Most Useful In Regions Where MoIs-
turs 10 Often Controlling Factor
In Crop Production - Ar
Drought RssIstant.

(By CARLETON r. BALL. Bureau Of
Plant Industry. U. g. Department Of AZ
rculture.)
In general there are two ways by
which the grain-sorghum crops can be
made Of greater value to the grower.
The hrst is by improving the varie-
ties; tho second. by finding more rap
Id and economical methods Of har-
vesting. Improved varieties can be
obtained through selection OF present
sorts and by lettering the methods Of
growing them. More rapid and eco
nomical harvesting will come about
either through adapting the crops to
present machinery or through the in
vention OF new machines. or both.
There are five principal ways in
which improvement may be made:
% Increased drought resistance.
(2) increased earliness, (3) dwarfer
stature. ~ greater productiveness.
and (5) increased machine harvest
ing.
The grain sorghums are most use
full in regions where moisture is often
the controlling factor in crop pro-
duction. Much good should therefore
be accomplished by increasing their
drought resistance, especially in the
areas Of lighter rainfall.
No one knows exactly what drought
resistance is. 1t is probable that
what we call drought resistance Is
the effect Of several different factors.
The most important Of these factors
are probably (1) increased ability to
prevent the loss OF water by traEspi-
ration. (2) increased development Of
the root system, and (3) a possible
increase In power to extract water
from dry soil.
Differences in the power to control
Transportation are well-known and
readily observed facts. By transpira-
ton is meant the passing OF water
from the tissues of the plant into the
air. In the processes of their growth
all plants are constantly absorbing
water from the soil through their
rootlets and allowing certain quanti-
ties of this moisture to pass out into
the air through minute pores, called
stomata. This is done in much the
same manner as water escapes
through the animal skin in the form
Of perspiration. In times of drought
1t is important that the plant lose as
little as possible Of its water supply
In this way. The plant best fitted to
prevent Transportation is thus the most
drought resistant In cact. for in
stance. this ability is highly perfect
ed. Corn Is much less drought resist
ant than the members Of the various
groups Of sorghums. Corn Is in dan
ger when the leaves begin to curl,
but sorghums often remain in this
condition for long time without per-
manent injury.
The size and character of the root
system is probably strong factor in
drought resistance. The larger the
root system in proportion to the plant
the better 1t can supply moisture. The
wider and deeper its penetration, the
larger the area of soil from which 1t
draws moisture In times of drought.
A deeply roofing plant may be able
to secure water when shallow root
systems lie wholly In dry soil. This
is entirely apart from possible diff
ferenoes In ability to secure moisture
from given unit Of soil Such differ
ences may exist, but the idea is only
q theory as yet Unfortunately, the
character Of the root system cannot
be observed while making observa-
tons.