SEPTEMBER 1958
Effects of
STORAGE and FORCING ENVIRONMENT
on EASTER LILY GROWTH
TOK FURUTA, Associate Horticulturist
T HE lily, Lilium longiflorum, has
long been symbolic of the Easter sea-
son. Many varieties are available for
use as potted plants and cut flowers.
The most common variety used for
pot plants is Croft. It has large, heavy
foliage, short height, a fairly high bud
count, and large flowers of excellent
quality. Unfortunately the variety in use
is a mixture of many strains, many of
which make inferior plants when forced
for Easter. Furthermore, since the plant
is grown from a bulb, many of the fac-
tors leading to successful growth and
flowering are not under the grower's
control. In addition, since Easter falls
on a different date each year, conditions
will differ each year as to storage
length, forcing temperatures, and light.
Therefore, the southern greenhouse op-
erator is faced with a difficult problem
in the culture of the Easter lily.
Experiments were conducted from
1950 through 1955 at the API Agricul-
tural Experiment Station, to determine
the influence of some storage and cul-
tural variations on the growth and flow-
ering of the Easter lily for Alabama
conditions.
STORAGE LENGTH and
TEMPERATURE
Commercial varieties of lilies- Geor-
gia, Creole, Croft, and Croft Special (a
selected strain of Croft)- were used
in these tests. The storage temperatures
were 32' F. and 45' F. The storage
lengths were 5, 10, 15, or 20 weeks.
All plants were forced at 60' F. after
potting.
Briefly, results from this phase of
the experiment were: Plants from bulbs
stored at 450 F. for 5 weeks matured
a little earlier than those stored at 320
F. However, the plants were taller and
had a higher bud count. Plants from
bulbs stored longer matured earlier,
were shorter, and had fewer flowers.
This was more noticeable at 450 F.
STORAGE CONDITIONS and
FORCING TEMPERATURES
Croft
Croft lily bulbs were stored at 450
F. in either moist or dry peat moss.
These bulbs were potted in a mixture
of three parts loam soil and one part
STATION
INSTITUTE
Auburn, Alabama
AGRICULTURAL EXPERIMENT
of the ALABAMA POLYTECHNIC
E. V. Smith, Director
_ I_ 11_
LEAFLET 59
manure. The plants were forced at a
temperature of 500 or 600 F.
At maturity the plants were shorter
when forced at 500 F. than at 600 F.
Treatment did not influence the num-
ber of flowers. The number of leaf
scorches (necrotic areas in the leaf
along the margin or tip of the blade)
was less when the plants were grown
at 500 F. Dry storage seemed to be
slightly better to prevent the amount
of leaf scorch.
Georgia
Bulbs of the Georgia variety of
Easter lily were stored at 450 F. Storage
treatment consisted of storing the bulbs
in moist or dry peat moss. Forcing tem-
peratures were 500 and 600 F. A group
of plants was shifted from one tem-
perature to the other when flower buds
became visible.
The bulbs that were stored moist
began to grow earlier than those stored
dry. This difference was more notice-
able throughout the forcing period when
forced at 500 F. The bulbs stored moist
flowered earlier. However, the final
height was approximately the same. The
number of flowers, also, was approxi-
mately the same.
Forcing at 600 F. resulted in a
shorter forcing period than forcing at
500 F. or any combination of the two
temperatures.
LIGHT, TEMPERATURE, and
SOIL MOISTURE
I
Experiments in 1952
To determine the influence of mois-
ture content of the soil, the following
treatments were used: (1) normal wa-
ter; (2) limited water - one-half the
frequency as (1); and (3) excessive
water- watered every day. The plants
were grown in full sun and kept at a
night temperature of 600' F. in the
greenhouse.
Increasing the amount of water sup-
plied resulted in taller plants at flower-
ing. However, the number of flowers
per plant was not influenced. At the
same time, the number of leaf scorches
increased as the amount of water sup-
plied increased.
Experiments in 1953
During the winter and spring of
1952-1953, Croft lilies were grown
using all combinations of the following
factors: (1) full sunlight and 50 per
cent reduction in light intensity; (2)
minimum of 500 and 600 F. night tem-
peratures for forcing; and (3) watered
when the soil was dry, and watered at
one-half this frequency.
Height of plants was less when the
water supply was decreased, but re-
ducing the amount of water supplied
to plants did not change the time of
flowering or reduce the number of
flowers per plant.
The plants grown in full sun were
shorter in all treatments, but the num-
ber of flowers remained constant. Full
sun hastened flowering at a minimum
night temperature of 600 F. At a night
temperature minimum of 500 F. there
was no difference between the light in-
tensities in regard to time of flowering.
Forcing the plants at 50' F. re-
sulted in slower flowering, slightly more
flowers per plant, and slightly shorter
plants.
Experiments in 1954
The treatments were all possible
combinations of various forcing tem-
peratures, light intensities, and mois-
ture supplies. Minimum night tempera-
tures used were 500 and 600 F. Light
intensities in the greenhouse were full
sun and one-half shade. Soil moisture
supplies were: (a) field capacity main-
tained; (b) dry - water applied at one-
half the frequency of (a); and (c) very
dry - water applied when the bulbs
were potted. From potting until flower
bud initiation began, these plants re-
ceived water only after wilting oc-
curred. From flower bud initiation to
flower, field capacity was maintained.
At lower temperature the plants grew
more slowly. The low temperature re-
sulted in more flowers, shorter plants,
and fewer nodes per plant. Increasing
the light intensity resulted in shorter
plants, more flowers, and fewer nodes.
Height of the plants and the number
of flowers was directly proportional to
the amount of water supplied. Keeping
the plants very dry initially resulted in
fewer nodes per plant. Forcing time
was not influenced by the amount of
water supplied.
When the plants were kept very dry
until flower buds initiated and the
plants were kept in full sun, there was
little difference in the height of the
plants because of temperature. The
lower temperature resulted in more
flowers per plant.
SUMMARY and
RECOMMENDATIONS
Storage Treatment
Increasing cold storage length before
the Easter bulbs were forced resulted
in faster maturity, shorter plants, and
fewer flowers. This was more pro-
nounced when the plants were stored
at 450 and 32' F. These changes were
more noticeable after 10 to 15 weeks
of storage. For storage periods of less
than 15 weeks, the warmer temperature
was desirable to speed maturity. For
longer storage periods, the cooler tem-
perature was best for maintaining maxi-
mum number of flower buds.
There was no advantage for using
moistened peat moss over air-dry peat
during cold storage.
Forcing Treatment
The forcing temperature, light inten-
sity, and amount of water supplied the
plants influenced quality of the plants.
Warmer forcing temperatures resulted
in faster maturity than lower tempera-
tures but the quality was poorer. It
was best to begin forcing at a cool
temperature (50' F.) and to withhold
water. The amount of water was in-
creased when the flower buds began
to form. The temperature was then in-
creased to 600 F. after growth began.
Any reduction in light intensity re-
sulted in taller plants. Therefore, it was
of utmost importance to keep the plants
in full sunlight.
Timing
The average number of days for va-
rious stages to be completed is given
in the table. The flower buds were ap-
proximately 0.4 inch in length when
they became visible without moving
the leaves. At the time the buds bent,
they averaged 2.2 inches long. Just
before the flowers opened, they aver-
aged 6 inches in length. It is obvious
that the flower buds elongated faster
daily as they approached full bloom.
DAYS REQUIRED FOR EASTER LILY FLOWER DEVELOPMENT
Days for various stages of growth
Temperature Water Pot Growth to Visible Bud bend
supply to visible bud to to Total
growth buds bud bend flower
500 F. Normal 27 49 24 16 116
1/2 normal 28 54 22 15 119
Dry 32
600 F. Normal 19 46 20 13 98
1/2 normal 19 45 22 13 99
Dry 31