The factor affecting the spiking of
Phalaenopsis
include
day and night temperature, light intensity, fertilization concentration
and hormone concentration
The quantitative Spiking model of Phalaenopsis is introduced:
I.
Illustration of the spiking model
The spiking percentage is from 0% to 100%; its model is shown as
follows:
Spiking percentage (P) = 100%〔Mature
index, 〕
〔Accumulated
cooling temperature index, ACT〕^{b1}
〔Accumulated
light intensity, ALI〕^{b2}
〔Fertilization
utilization index, FUI〕^{b3}
〔Hormone
concentration, HC〕^{b4}
(1)
1.
Mature index,
The mature index is used to express the
maturing conditions. The value of
is
from 0 to 1. The numeric value varied by the orchid variety and carbon
accumulation. The mini verities can reach 1.0 after 6month’ culture
time. Big white varieties require 18 months. With normal culture
conditions of temperature, light intensity, fertilization and other
factors, the value
could equal 1.0.
2.
Accumulated cooling index, ACI
the accumulated cooling index (ACI) index
is calculated as follows:
(2)
The accumulated cooling temperature (ACT) is used to
as an environmental variable. It is calculated by follows:
(3)
where is
the adequate culture temperature during the day;
is
the daytime temperature of the cooling room, H_{d} is
the day period in hours; is
the adequate culture temperature at night;
is
the nighttime temperature of the cooling room; and H_{n}
is the night period in hours.
3.
Accumulative Light Intensity, ALI
The definition of terms concerning light intensity is as
follows:
:
Light intensity in the cooling room,
:
Low limitation value of light intensity
:
High (endurance) limitation value of light intensity
:
Accumulated hours for the light intensity of the cooling room range from
to.
a. If ＜,
ALI=0 (4)
b. If ＞,
ACI=0 (5)
c. If ＜＜,
ACL=
(6)
is
the light intensity factor.
4.
Fertilization utilization index, FUI
The FUI is calculated as follows:
FUI=
(7)
where is
the applied quantity of phosphorus;
is
the basic requirement of phosphorus;
is
the applied quantity of nitrogen,
is
the basic requirement of nitrogen;
is
the applied quantity of other fertilizers; and
is
the basic quantity of other fertilizers.
is
the limitation of phosphorus,
is
the limitation of other fertilizers. If
＞＞
or ＞,
.
The value
is from 0 to 1 and is affected by the characteristics of varieties.
5.
Hormone concentration
The safety criterion of the hormone concentration is.
If the applied concentration is greater than,
the spiking model is meaningless.
II.
Application of the spiking model
Equation (1) could be expressed as follows:
(8)
The parameters of b_{1}, b_{2}, b_{3}
and b_{4} represent the effect of temperature, light intensity,
fertilization concentration and hormone concentration, respectively.
In The Netherlands, temperature and light intensity are domain
factors. Research by the company Anthura indicated that
and
It
represents that the effect of temperature is about 60%, light is 30% and
other factors are 10%.
A typical Phalaenopsis variety is cooled in The
Netherlands. The typical index is:
.
After 6 weeks’ cooling, ALI=0.985, FUI=1.0 and HC=1.0.
The spiking percentage is:
= 98.05% (9)
For the Taiwan orchid industry, the cooling
temperature is the main factor.
The spiking model used in Taiwan is as follows:
(10)
That is, the temperature accumulation is at 70%, and light
intensity has 20% effect, fertilization concentration have 8% effect and
for Hormone 2%.
For the amabilis variety, the index
isasfollows:,
by equation (10),
Table 1.
Environmental factors for different stages of several main
Phalaenopsis varieties


Data sources:
Culture Guide
of Floricultura b.v. 
Big white variety: V3 
Small white
variety:
amabilis 
variety:
HsinYen
Beauty 
variety:
Fortune
Saltzman 
variety:
Queen
Beer 
I. Growing
Stage 
1.T_{dg}
2.T_{ng}
3.Light 
28℃
26℃
45006000 lux 
2832℃
2325℃
23000 lux 
2430℃
2224℃
16000 lux 
2630℃
1926℃
18000 lux 
2430℃
1822℃
15000 lux 
2832℃
2023℃
15000 lux 
Ⅱ.
Pretreatment 
1.T_{dp}
2.T_{np}
3.Light 
28℃
26℃
45006000 lux 
3034℃
2325℃
28000 lux 
2832℃
2224℃
20000 lux 
2832℃
1926℃
21000 lux 
2830℃
2122℃
18000 lux 
3032℃
2023℃
18000 lux 
Ⅲ.
Spiking 
1.T_{dc}
2.T_{nc}
3.Light 
20℃
18℃
70008000 lux 
2024℃
1722℃
26000 lux 
1822℃
1820℃
18000 lux 
1824℃
1719℃
20000 lux 
1820℃
1718℃
16000 lux 
2024℃
1819℃
16000 lux 
Ⅳ.
Spike
extending 
1.T_{de}
2.T_{ne}
3.Light 
23℃
20℃
6000 lux 
2226℃
1722℃
23000 lux 
2024℃
1822℃
18000 lux 
1824℃
1719℃
18000 lux 
1822℃
1718℃
16000 lux 
2024℃
1819℃
16000 lux 
Ⅴ.
Blossoming 
1.T_{db}
2.T_{nb}
3.Light 
23℃
20℃
6000 lux 
2024℃
1822℃
22000 lux 
2024℃
1822℃
16000 lux 
1823℃
1719℃
18000 lux 
1820℃
1718℃
15000 lux 
2022℃
1819℃
15000 lux 
Note:
1. Growing temperature at day and night, T_{dg}, T_{ng}.
2. Pretreatment temperature at day and night, T_{dp},
T_{np}.
3. Cooling temperature at day and night, T_{dc},
T_{nc}.
4. Spike extension temperature at day and night, T_{de},
T_{ne}.
5. Blossoming temperature at day and night, T_{db},
T_{nb}.
About the author:
Professor Chiachung Chen, Ph. D.
Biosystems Engineering Laboratory
National ChungHsing University
250 KuoKuang Rd.,
Taichung, Taiwan 40227
Tel: 886422857562, Fax: 886422857135
Web site: http://amebse.nchu.edu.tw/orchids_cultivation.htm
Email: ccchen@dragon.nchu.edu.tw 