The Black Hills union and western stock review. [volume] (Rapid City, S.D.) 1904-19??, 1910-01-14
CRITICAL PERIODS
Certain Times When Nothing I'm
pedes Growth Of a Crop.
Should Be Determined. " Possible, at
What Stage Of Growth Plants Are
Most Likely to Be In Need
Of Water.

Prof. +. d. Farrell of the Office O.
| grain investigations. United States de
| partment of agriculture. superintend
ent of experimental station at Nephi
Utah. at the recent Dry Farm Con
gress held at Billings, Mont, discussed
the Importance of certain critical perl
DDS In dry land crop production. HI
said in part:
The most casual observation o
the behavior of a given crop during
the period Of It's growth. from the
termination of the seed to maturity
Will disclose the fact that, at certain
times. the plants all seem to do abou
equally well; nothing seems to i'm
pede their steady. uniform. rapid
growth. On the farm. during these
times. the variations in the character
OF the SOIL or in its condition OF tiltl
appear to have no effect on the crop;
all over the field. the crop grows
rapidly and uniformly. And in an ex
detrimental field, no differences at
tributable to different methods of til
lage. to variety characteristics. tic
various rates or times of planting
ETC.. can be observed. In short, there
are times In the life Of crop when
everything seems to favor its growth
and when all the crop requires is to
be left unmolested. Such periods as
these are comparatively negligible.
from the standpoint OF both the farm.
er and the agricultural Investigator.
But these times of absolute pros.
perlty for field OF plants are usually
short and infrequent. especially on
the dry lands. Before the crop has
matured. 1t is practically certain to
experience several periods in which
the plants are subjected to conditions
OF the most trying severity. These
conditions may be due to disease, soil
crustsng. frost. soil-blowing. etc. but
most frequently In the really arid
sections the difficulty arises from
drouth. 1t Is when one or more Of
these unfavorable conditions exist
that the excellence or the inferiority
of the methods applied by the farmer
appears. Also. during these times
the process of natural selection-the
survival of the fttest and the elimi-
nation of the weak-is most active.
This statement applies with equal
truth to the farmers themselves and
to the plants in their fields. For the
purposes Of this discussion. we snail
designate these durations Critical
Periods and with view to calling
special attention to their Importance
In dry-iand crop production. this
paper has been prepared"
Prof. Farrell cited examples to
elucidate his definition of a critical
period and continued:
AS to the selection of location
and the choice of crops. the total an.
nual amount of distribution through.
out the year. and especially among
the growing months. should invari-
ably be taken into account. More
over. as indicated by our experience
with alfalfa. 1t should be determined,
II possible. at what stage Of growth
the plants Of crop are most likely
to need an abundance of water. This
being known, 1t should be determined
whether in the section under consid-
the necessary moisture could
be made available at the proper time.
In other words. It is unwise to say
that wheat. for example, can be sue
cessfully grown In a given country be-
cause that country receives an aver
age annual rainfall Of IL inches or
even 20 inches. 1t must be known
the country Is frequently
subjected to what would be critical
periods for the crops to be grown
there. The length and intensity of
these periods also should be consid-
cred"