, 1899-01-16
.SEED TERMINATION
FROM AN INTERESTING AND VAL
UABLE BULLETIN RE
GENTLY ISSUED.
Series Of Experiments Showing the
Effect OF Various Percentages of
Alkah Upon the Termination of
Different Kinds of Seed-Effect of
Different Alkali Salts.

IL Oh plants, we obviously must know
what that effect is. How does the al
kali limit the plant? Although it will
be many years before any complete an~
swer can be given to that question, yet
the study of the subject by the station
has cleared up some of the simpler
points. For the simplification of the
prblem it was divided into two parts,
the effect of alkali on the termination
of the seed and its effect on the growth
of the plant. Only the first part of the
work will be made public here.
The effect of alkali on the germina-
ton of seeds depends on three things.
the kind of seed, the kind OF alkali and
the concentration of the alkali solution,
Sometimes the seeds in alkali solution
are killed. sometimes they terminate
but very slowly, sometimes they ger
inmate more quickly as compared with
those in pure water. The usual result
Is that the seeds are delayed in germin-
alton for a long time. Now IN Wyoming
the a is toe short anyway, and
even a few days delay will make a diff
ference between a crop and a failure.
A necessary preliminary TO germ
ination is the absorption of water, and
1t seemed likely that the retarded ef-
feet of the alkali on the termination
was due to its hinderering the seed
from absorbing the water it needed.
Experiments showed that this was the
case, and work on this line has been
carried on in the chemical labratory
for about three years now. The tech
nical details will be published in the
annual report Of July next, but a table
showing the results Of one Of the ex-
periments is here given t show how
much work is carried on. Wheat was
the seed experimental upon in this
case and an equal weight OF it was put
into solutions of the common alkalies
of the various strengths, pure water,
and a solution of sugar introduced for
comparison. 1t was found that the alb
by the kind of alka1i or the strength
of the solution, but purely by the os-
motto pressure. Osmetic pressure is
not generally understood and in fact
is a comparatively new conception in
science, but it Is easy to explain what
1t means. In this case 1t simply means
that the water passes through the little
coatings in the seed opens more easily
the particles Of salt. and conse-
quently the seed will take up water
more rapidly If no salt is present. To
give a rough illustration, a pump sup
plying city water works will get more
water through the screen OF the intake
pipe if the holes Of the screen are not
partly clogged with sand and drift
wood. In this experiment, the solu-
tions of sugar, sodium sulphate, mag
nesium sulphate, and sodium chloride
were SO made as to have the same os-
motto pressure.
Wheat absorbs just about the same
amount of water from each of these
in the same length of time. Sodium
carbonate (black alkali) acts different
ly, for when it is strong it attacks and
destroys the seeds themselves. Some
seeds, too, give quite different results.
Beans absorb the same amount of
when put into a saturated solu-
ton Of common salt as they do when
put into pure water. The dissolved
apparently passed into the bean as
readily as the water and destroys its
power of termination. Rye is inter
mediate between wheat and beans II
this respect.
To decide the question whether the
absorption Of water is physical of ply
comparative tests were made
between living seed in which the power
of termination had been destroyed by
age, heat, O r exposure to formaldehyde
vapor. No difference between the liv-
ing and dead seed has yet been observ-
ed, so it appears that water is drawn
into the seed purely by such physical
forces as surface tension and osmotic
pressure. 1t does not appear that the
salts mentioned, except sodium carbon
ate, exert n poisonous influence on
the wheat. 1t terminates readily when
removed from the alkali solutions and
put under favorable conditions.
The absorption of water is retarded
and diminished by the presence Of salts
in the water, but not prevented. This
is due to the TACT that the seed allows
the salt to pass into it though not 80
readily as the water. . The volume of
the swelled seed and the amount of
salt they contain has been determined
and 1t appears that IN strong solutions
enough salt Is absorbed to make the
solution inside the seed nearly
the same strength As the outside. In
this way the resistance to the absorb
ton Of water due to osmotic pressure
CONTINUED On Page 81