Catoctin clarion. [volume] (Mechanicstown, Md.) 1871-1940, 1920-06-03
PLANT LIFE IS
RULED BY LIGHT
U. S. Experts, After Experiments,
Advance Principle That Is
Revolutionary.
TEMPERATURE IS NEGLIGIBLE
Fiowering and FruitIng Period Of Prac.
tieaIly Any Plant Can Be Controlled
by Lenothenins Day by Arti.
fetal LIGHT.

Washington, D. C.-Government ag-
ricultural experts have discovered that
plant life seems to depend on light,
rather than temperature. for nourish>
ment and may be controlled by reg,i-
latng the hours of light and darkness.
The principle is revolutionary but
1t rests on actual experiments, in which
1t was demonstrated that plants SUBJ
jerted to alternate periods Of light and
darkness In carefully determined pro,
nrrtionS could be brought to maturity
at any time of the year.
"GreenhOuse experiments" says All
announcement by the department Of
agriculture, prove that the Towering
and fruiting period of practically any
plant con he made to take place mt any
time Of year by darkening the green
house in the morning and evening, II
the day is too long. or by lengthening
the day by artificial light If the day is
too short
Flowers That Bloom In Spring.
Spring flowers and spring crops
happen to be spring flowers and spring
crops because the days at the season
Of their Towering and fruiting have
the proper number Of hours of day
light"
The discovery may be of the highest
importance in the future planning Of
cropping systems for different regions.
Eventually it may be found, Accord
ing to w. w. Garner and H. A. Allart,
scientists in the bureau of plant indus
try. who conducted exhaustive expert
ments, that the animal organism also
is capable Of responding to the stimu-
lus of certain day lengths. They be-
lieve that the migration OF birds may
he an Illustration, on the ground that
direct response to such stimulus
would be more In line with modern
biological teachings than theories
which assume that birds "go south
as a matter of instinct.
Experiments were conducted with a
large variety of plants. 1t was shown
conclusively that too little Sleep" or,
in other words too many hours of day
light, would prevent many plants from
even reaching the Towering and fruit
ing stage.
1t was found also that plants would
not reproduce except when exposed to
a favorable length of day, although too
much daylight for Towering and fruit
ing might stimulate profuse vegetatlve
growth. A length of day favorable
both to reproduction and growth re-
suits in the "ever-bearing" type Of
fruits.
BY employing dark chambers the sci.
entists shortened or heightened the
life cycle of plants and forced some Of
them to complete two cycles in one sea-
son. Violets, which naturally bloom
only during the comparatively short
days of spring. when covered with
lIght-pr0of boxes for time were made
to bloom again during the summer.
Biloxi soy beans exposed to the light
for only five hours day Powered near
ly three months earlier than plants left
in the light all day, but attained only
about one-eighth Of the height.
Temperatures Effect Slight
Temperature appeared to exert he
influence in the tests. A striking IL
lustration of the relative untmportance
OF temperature was givea IN the fact
that plants kept In the dark for part
of the day underwent In midsummer
the changes that in nature come in the.
fall and that, heretofore, have been at
tribated to lower temperatures. This
was true even when the dark houses
registered a higher temperature. than
the outside atmosphere.
THE length Of the day." the depart
ment's announcement said, ''is proved
to be the most potent factor in deter
mining the relative proportions be-
tween the vegetative and frutting parts.
Of many crop plants. Indeed, fruiting
may be completely suppressed by
day too long or too short. This new
principle undoubtedly explains the En-
ratio behavior which has been observed
with many crops when they are shifted
10 different ATTITUDES"