Middletown transcript., 1920-04-10
GAN CHANGE. ].
PLANTS. SEASONS
Experts Prove Maturity Can Be
Regulated by Light
VARIETIES UNDER THE TEST
Government Scientists Find Tempera.
ture Appears To Exert No In.
fluence In Expert.
mentS.

nent8.
Washington.-Gover agricul-
tural experts have discovered that
plant life seems to depend on light
rather than temperature for nOurish-
ment and may be- controlled by regu-
lating the hours of light and darkness.
The principle is revolutionary, but
it rests on actual experiments in which
1t was demonstrated that plants sub
jected to alternate periods of light
and darkness in carefully determined
proportions could be brought to ma
turity at any time of the year.
Green house experts" says an an
nouncement by the Department of
Agriculture, prove that the Towering
and fruiting period of practically any
plant can be made to take place at
any time of year by darkening the
green house in the morning and eve
ming the day is too long or by length
ening the day by artificial light II
the day is too short.
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 the highest
importance in the future planning OF
cropping system for different regions.
Eventually it may be found, accord
ing to w. w. Garner and H. A. Allard,
scientists in the Bureau Of Plant In
dustry, who conducted exhaustive ex-
periments, that the animal organism
also is capable of responding to the
stimulus of certain day lengths. They
believe that the migration of birds
may be an illustration, on the ground
that direct response to such stimu-
lus would be more in line with modern
biological teachings than theories
which assume that birds "go south"
as matter Of instinct.
Experiments were conducted with a
large variety Of plants. It was shown
conclusively that too little "sleep, or,
in other words, too many hours of day.
light, would prevent many plants from
ever reaching the Towering and fruit
ing stage.
1t was found also that plants would
not reproduce except when exposed
to favorable length of day, although
too much daylight for Towering and
fruiting might stimulate profuse veg
etive growth. A length of day favor
able both to reproduction and growth
results in the lever bearing" type of
fruits.
BY employing dark chambers the
scientists shortened or heightened the
life cycle of plants and forced some of
them to complete two cycles in one
season. Violets, which naturally bloom
only during the comparatively short
days of spring, when covered with
lightproof boxes for time, were
made to bloom again during the sum-
mer. Biloxi soy beans exposed to the
light for only five hours day flow
cred nearly three months earlier than
plants left in the light all day, but at
tanned only about one-eighth the
height.
Temperature appeared to exert no
influence in the tests. A striking H.
lustration of the relative unimport-
ance Of temperature was given in the
fact that plants kept in the dark for
part Of the day, underwent in mid
summer the changes that in nature
come in the fall and that heretofore
have been attributed to lower temper
atures. This was true even when the
dark houses registered higher tenn
perature than the outside atmosphere.
Iris kept in artificial light for 18
hours day bloomed in two months,
while others in the same temperature
but without artificial extension of the
day required months longer.
'The length Of the day." the depart
ment's announcement said, sis proved
to be the most potent factor in deter
mining the relative proportions be-
tween the vegetative and fruiting
parts Of many crop plants. Indeed,
fruiting may be completely suppressed
by a day too long or too short. This
new principle undoubtedly explains
the erratic behavior which has been
observed with many crops when they
are shifted to different latitudes."