How to produce the high quality Phalaenopsis
The beautiful orchids, Phalaenopsis pot plant, have the highest price of the
ornament plants for a long time. However, due to the over-supply, the price is
decreased sharply in 2008. Low quality flowers have been drove out the market. Only
the high quality orchids could obtain the benefit. The topic of this paper is to discuss
the basic techniques to produce the high quality Phalaenopsis.
1. The special characteristics of the organs for Phalaenopsis
The important organs for Phalaenopsis are the roots, leaves and spikes.
1.1. Roots
The functions of roots include fix the plant in the substrate and absorb water and
nutrients. The structure of root contains chlorophyll, so the natural color is green.
Roots have the ability of photosynthesis and assimilation. The adequate environment
for roots is surrounded with moist (vapour) and not to soak into water.
The nutrients dissolved in the water can not be adsorbed by roots directly. The
nutrients are adsorbed with the vapour in the air. So the adequate substrates for
Phalaenopsis must have the ability to provide the moisture, fresh air (Oxygen) and
nutrients.
If the pot material is transparent, the light can pass the pot wall and provide the
energy of photosynthesis. The color of health roots is green and bright.
1.2. Leaves
The most important organ for Phalaenopsis is leaves. Leaves have the
1
photosynthesis ability for carbon fixation and the assimilation function to store the
available carbon. The nutrients can be adsorbed into leaves directly, except of Ca and
Mg. The required carbon sources for spikes and flowers are provided from leaves.
1.3. Spikes
The natural color for spikes is green. Its structure contained chlorophyll and have
the photosynthesis ability same as that of leaves and roots. However, the assimilation
materials are not enough for the development of spikes and blossoms. So the required
dry matter of spikes and blossoms is provided by leaves.
The priority of dry matter distribution for Phalaenopsis is different with other
plants. Roots are the first one to obtain the dry matter. The ranking of dry matter
distribution is: roots＞leaves＞spikes＞blossoms.
2. The coexistence for vegetable and reproductive phase
Most of the orchids have vegetative stage and reproductive stage. The plants at the
vegetative stage are in the state of growing and developing. The plants at the
reproductive stage are in the state of spiking and flowering. The distinction between
two stages is so obvious for many orchids. Oncidium is a typical orchids. At the
vegetative stage, the dry matter are produced and stored in pseudobulbs. At the
reproductive stage, the leaves stop the photosynthesis function. The required nutrients
of spikes and blossoms are taken from pseudobulbs.
Phalaenopsis has its special characteristics for vegetative and reproductive stages.
As plants develop from tissue culture plantlets to reach the mature stage, it is in the
vegetative stage. As these mature plant are moved to cooling environment for spiking
and, it is in the reproductive stage until the length of spikes is reached to 3-5 cm.
However, two stages are coexistence at the flowering phase. The spikes are
lengthened continuously and buds are appeared (reproductive stage). The leaves
2
accumulated dry matters and send them to spikes and blossoms (vegetative stage).
That is, the required dry matters of spikes and blossoms are taken from leaves. The
leaves need to supply the dry matter to spikes and blossoms in the flowering stage.
The microclimate control and fertilization work are so important at the flowering
stage. The leaves must be maintained in the optimum day and night temperature. The
light intensity and period are also important. The nutrients need to be supplied
correctly. So the leaves can accumulated enough dry matters and send it to spikes and
flowers to ensure the flower quality.
3. The factors affecting the Phalaenopsis quality
3.1. Genotype
The genotype characteristics of the Phalaenopsis variety includes flower color,
pattern, flower size, flower numbers, numbers of spikes, multi or no branch, and stem
height, et al,.
3.2. Health conditions
The plant must maturity enough before to be sent to cooling room. It must store
enough dry matters in plants. The plants required no disease, no pest damage,
virus-free, no chemical damage, no salt accumulation in substrate.
3
Figure 1. These plants are in good conditions for cooling treatment
3.3. Environment
The environmental factors, such as day temperature, night temperature, relative
humidity, light period and intensity must be kept at optimum range.
The interaction of genotype, health conditions and environment needs to be
emphasized. The genotype decides the maximum possible for the expression of flower
quality. For example, the genotype of flower numbers for the little white flower, P.
amabilis, is more than twenty. If the plant is mature enough and the cooling
environment is kept at good conditions, the grower will obtain more than twenty
flowers for each plant. However, the number of flower will decrease as the plant is
immature, or damage by disease or pest, or the temperature or light intensity do not
maintain well.
The effect of microclimate on other flower qualities was described as follows:
4
3.2.1. The temperature difference of vegetative stage and cooling stage
The numbers of spike is affected significant by the temperature difference
between vegetative phase and cooling phase. The "Mansanfong" variety is used to
illustrate the effect of the temperature difference on the number of spikes. The
adequate day and night temperature for vegetative stage is 28℃and 26℃. If the
cooling temperature of day and night is kept at 25℃and 20℃, these plants have 100
％ of the single spike. As the cooling temperature of day and night is maintained at
23℃ and 20℃, these plants have 40％ of the two spikes and 60％ of the single spike.
At the environment of 20℃ day temperature and 18℃ night temperature, these plants
have 100％ of the two spikes.
3.2.2. The difference between day and night temperature at flowering stage
The symbol of DT represents the difference between day and night temperature at
flowering stage. As DT increase, the length of spikes (or stems) is lengthened. As DT
decrease, the length of spikes (or stems) is shortened.
Figure 2. DT increase, the length of spikes is too long
5
3.2.3. The day temperature at flowering stage
If the day temperature at flowering stage is same or higher than that of vegetative
stage, leaf will appear in the stem. It is called as “Keiki’s”. In spite of the day
temperature did not higher than the temperature of vegetative stage, but it still higher
than the normal condition, the high day temperature reduce the flower quality. The
position of the first bud is heightened, all buds will be blocked up in the end of stem,
the flower color will fade and the number of branches is decreased.
Figure 3. Keiki’s of the Phalaenopsis
6
Figure 4. All buds will be blocked up in the end of stem because the day
temperature is too high
3.2.4. The night temperature at flowering stage.
If the night temperature at flowering stage is higher than the adequate condition,
the number of blossoms is decreased and the flower size is reduced.
4.
The diversity characteristics of Phalaenopsis varieties.
The required qualities are two or more spikes, multi-branching, bright color, and
40-75cm height in the Holland. According to the Culture Guide of Floricultura
b.v., the adequate environment conditions for Phalaenopsis are listed as following:
Table 1. The adequate environment conditions for Phalaenopsis
Vegetative phase
day temp
night temp
light intensity
28℃
26℃
4000-6000lux
7
Cooling
20℃
18℃
7000-8000 lux
Flowering phase
23℃
20℃
7000-8000 lux
However, the growers usually found that many varieties could not produce the
required quality according to these environment conditions.
In the orchids greenhouse, leaves colour of some varieties was found that turned
into red and dark (Figure 5) in the Holland. Some varieties still be induced to spike at
the growing regions (day temp. 28℃, night temp. 26℃) (Figure 6). Some varieties
can not be induced any spikes at the cooling regions (day temp. 20℃, night
temp.18℃) (Figure 7).The reason for these results can be explained by the diversity
of Phalaenopsis varieties.
Figure 5. Leaves colour of different varieties was found that turned into red and
dark at the same light level
8
Figure 6. Some varieties still be induced to spike at the growing regions
(day temp. 28℃, night temp. 26℃)
Figure 7. Some varieties can not be induced any spikes at the cooling regions
(day temp. 20℃, night temp.18℃)
9
5.
The classification of the Phalaenopsis characteristics
5.1.According to the culture temperature
There are seven types of Phalaenopsis varieties classified by its optimum day and
night temperature in vegetative stage:
A.31-33℃ / 25-26℃, such as V3, P. Sogo Yukidian
B.28-30℃ / 24-25℃, such as P. amabilis
C.28-30℃ / 21-22℃, such as D. Queen Beer
D.24-25℃ / 20-21℃, such as P. Taipei Gold
E. 21-22℃ / 18-19℃, such as P. Fortune Saltzman
F. 26-31℃ / 21-24℃, such as D. Sin-Yuan Golden Beauty
5.2.According to light intensity
The required light intensity of the Phalaenopsis is influenced by the growing stage.
The required light intensity of mature plants is usually higher than that of small size
plants. A typical variety of big white flower, V3, P. Sogo Yukidian is used to illustrate
the levels of light intensity in different stages.
Table 2. The require light intensity at different stages for P. Sogo Yukidian
4.0 '' pot
25000 lux
3.0 '' pot
18000 lux
2.0 '' pot
10000 lux
flask
5000 lux
The effects of environment on the flower quality are presented as the following
case.
The beauty blossom of three spikes is showed in Figure 8. This variety is grown
10
at Pingtung County, southern Taiwan. The high day and night temperature (32℃/26℃)
and high light intensity (25000 lux) was provided. Then plants were sent to the
cooling room (day and night temperature was 23℃ /18℃, light intensity was 28000
lux). As the healthy and mature plants were placed in cooling rooms, three spikes are
induced. Larger and beautiful blossoms are founded in this plant.
Figure 8. The beauty blossoms of three spikes for V3, P. Sogo Yukidian
Some plants were transported to the New York State, USA. The microclimate in
that greenhouse for the growing stage was set at 22℃ (day) and 20℃ (night). The
light intensity was maintained at 16000 lux. In this condition, these plants did not
have the enough sources for photosynthesis. The accumulated dry matter was
insufficient for further utilization. As the greenhouse temperature was decreased with
the season change and the spikes were induced. The quality of spikes and blossoms
11
can not correspond to the market requirement (Figure 9)
Figure 9. The quality of spikes and blossoms of V3, P. Sogo Yukidian in
New York
From the illustration of above case, the important of the characteristics of variety
need to be emphasized. That is the reason that many varieties of Phalaenopsis have
been send to the Holland. Some varieties had the excellent flowering quality. However,
many varieties did not appear the accepted quality.
6. The selection of the adequate varieties for the Holland
6.1. The greenhouse microclimate
The microclimate of greenhouse for Phalaenopsis in the Holland is listed in
the Table 1. The day and night temperature are 28℃ and 26℃ for the vegetative
stage. The day and night temperature are 20℃ and 18℃ for cooling phase. So the
12
selection varieties of Phalaenopsis to provide to this country need to meet the
requirements of temperature and light intensity listed in the Table 1.
6.2. The required of variety for the Holland
The basic requirements of variety are the genotype and plantlet conditions
The genotype and others conditions of adequate varieties is listed as follows.
A. double or more spikes
B. medium or large size of blossoms, at least 8 cm
C. the number of flowers is 6 at least for each spike
D. bright color of blossoms
E. compact size, more plants can be placed per square meter
F. others, the plant conditions of plantlets are no disease, no insect damage,
virus-free, no chemicals damage, no salt accumulation in substrate. The
leaves and roots are kept at healthy.
About the author:
Professor Chiachung Chen, Ph. D.
Biosystems Engineering Laboratory
National ChungHsing University
250 KuoKuang Rd.,
Taichung, Taiwan 40227
Tel: 886-4-22857562, Fax: 886-4-22857135
Web site: bse.nchu.edu.tw
Email: [email protected]
13