MINISTRY OF EDUCATION
AND TRAINING
MINISTRY OF AGRICULTURE
AND RURAL DEVELOPMENT

VIETNAM ACADEMY OF AGRICULTURAL SCIENCES
HOANG XUAN LAM STUDYING THE GROWTH, DEVELOPMENT CAPACITIES AND
TECHNICAL MEASURES TO INCREASE YIELDS, QUALITIES OF
SOME EXOTIC ORCHID CULTIVARS (CATTLEYA, DENDROBIUM,
ONCIDIUM) FOR NORTHERN VIETNAM
Branch of study: Crop science
Code : 62 62 01 10 SUMMARY OF AGRICULTURAL DOCTORAL THESIS HANOI - 20141
INTRODUCTION

1. Urgency of research topic
Of all popularly planted types of flowers, orchids are known as a flower not
only beautiful, fragrant, multi – colorful, but also are of high economic value. So far,
mankinds have learned on more than 750 orchid branches with 35000 wild orchids
species and 75000 orchid cultivars as a result of selection and breeding [33].
In Vietnam, there are about 1003 species of orchids available [ 33 ]. These
are very abundant plant resources to serve the creatation and breeding of new
varieties of orchids. However, most of these orchids can only be exploited and
cultivated in natural conditions, technical measures have not yet been applied, so
their yields and qualities are not high that can not meet the requirements of
consumers. Whereas the exotic orchids have their advantages as having good
growth and healthy development, high yields , good quality of flowers: big flowers,
beautiful colors, various diversified, durable and long -lasting flowers and that their
flower blooming time can be controlled for the occasions of Holidays or Lunar
New Year Celebration, that has brought about high economic efficiency to growers.
Cattleya, Dendrobium, Oncidium are pretty orchids species popularly
esteemed by the markets. It is attractive to consumers with diversified colors,
beguiling aroma and especially, commercial producers are attracted by the
durability of flowers. However, the actual production of these orchids in Vietnam
still faces many difficulties. Lan Cattleya, Dendrobium , Oncidium orchids are very
suitable the climate in Southern areas as of its all - year-round warm weather, great
sun radiation and long appropriate sunlight for plant to grow and develop, whereas
the climatic condition in the North is not favorable due to high summer
temperatures (33 - 38

- To evaluate the adaptability of exotic orchids belonging to 3 branches of
Catlleya, Dendrobium and Oncidium (survival, growth and development
capabilities) in the period of nursery and in production gardens in order to select
some new promising orchid cultivars adaptable to ecological conditions of the
Northern Delta region.
- To study the effect of growing conditions (substrate, fertilizers, shading
system, flowering control) to the growth and development of selected hybrid
orchids in order to identify appropriate technical measures that help reaching high
yield, high quality of flowers for these orchids.
3. Scientific and practical significances:
3.1. Scientific significance
- The results of the study subjects have provided the scientific data on
basical criteria for an orchid to reach high yield, good quality as well as the
influence of growing conditions (temperature, light, substrate, fertilizer, ) to the
growth, development and the formation of flowers and flower quality of the
Cattleya orchid, Dendrobium, Oncidium in Northern Delta conditions.
- The study results are also references of great value for teaching, research
and production of orchid plants in general as well as Cattleya, Dendrobium,
Oncidium in particular.

3
3.2. Practical significance
- Having introduced to production 8 exortic hybrid orchids belonging to 3
branches of Cattleya, Dendrobium, Oncidium adapted to the ecological conditions
of the northern delta region with good stability, growth and development that meet
the requirements of selecting new orchid cultivars for production.
- Have proposed farming techniques to increase the capabilities for the


4
Chapter 1
OVERVIEW

1.1 General Overview of the orchid Cattleya , Dendrobium , Oncidium
Cattleya (Cattleya orchids) includes about 65,000 primitive species and
numerous outvarietal and intervarietal crossed species. They are native to tropical
America, mostly in the mountains with altitude from 600 - 1800 m [46].
Dendrobium (Hoang Thao orchid) is the largest genus in orchid family,
consisting of over 1,600 species whose distribution stretches from Korea, Japan,
Indonesia to Australia. In Vietnam, over 200 species of orchid Dendrobium has
been recorded [ 94 ].
Oncidium (dancing lady) consists of about 400-600 species originating from
the America and subtropical regions. They can be found from Florida to the
Bahamas, Caribbean Islands and southern Mexico, Central and South America to
Argentina [122].
By studying botanical characteristics and for external requirements for
Cattleyas, Dendrobium, Oncidium, it is shown that climatic condition of Vietnam
can absolutely be suitable for the culture of this species, particularly in the
provinces of the Southern region. However, because of the cold weather in the
northern provinces, the plants are less developed and grown. To develop this orchid
in production, it is necessary to pay special attention to the uses of substrates,
fertilizers, growth regulators, flowering stimulants and flowering control measures
on the occasions of Tet and Holidays.
1.2 The status on production and consumption of Cattleya, Dendrobium,
Oncidium orchids in the world and in Vietnam:
Export markets of orchids on the world are ever-expandin. European Union
(EU), North America and Japan are still biggist areas to consume most cut- orchids,
although China is also becoming an important market. Only 25 countries of the EU

potentiality. Meanwhile, the competitiveness on the world market is very huge. The
trading activities and export in recent years are only at launching stage that leads
to a promising future for development of these flowers basing on the existing
favorable conditions for the development of orchid growing branch.
1.3 Status of research on Cattleya, Dendrobium, Oncidium orchids in
the world and in Vietnam:
1.3.1 Status of research on Cattleya, Dendrobium, Oncidium orchids in
the world
For many years, due to high economic and aesthetic values of orchid plants,
that developed countries in the world have used traditional techniques and modern
methods for breeding and selecting flowers in general and for orchids in particular
and have achieved very satisfactory results, especially on some industrial orchids
as Dancing lady (Oncidium), Hoang Thao (Dendrobium), Cat (Cattleya) and some
other orchids and these have brought about big financial resources for orchids
producing branches in countries as Netherlands, China, Taiwan, Thailand
6
The above results show that the world has had a lot of research work on
orchid plants, in general and on the genera of Cattleyas, Dendrobium and
Oncidium, in particular. The study focused on a number of areas such as plant
breeding and seed multiplication, technical planting measures and measures for
pests and diseases preventions,
1.3.2 Status of research on Cattleya, Dendrobium, Oncidium orchids in
Vietnam
In Vietnam, there have been many studies on collectioconservation the genetic
resources of native orchids and exotic cultivars as well as evaluation and selection
of promising orchid varieties for production and concentrate to study technical
measures on substrates, fertilizers, flowering control techniques, pest prevention

in production as the controls (cntrl).
5 Dendrobium orchid cultivars, imported from Thailand, as seedling, after
the stage of tissue culture with height: 6-8 cm, number of leaves: 2-3 leaves / plant,
number of roots: 4-6 roots/plant and one Dendrobium cultivar which is widely
planted outside in production is used as the controls (cntrl).
- 6 one leaf Cattleya orchid cultivars imported from Thailand were used as
seedling after the stage of tissue culture with height: 5-7 cm, number of leaves: 2-3
leaves/plant, number of roots: 3-5 roots/plant and 1 cattleyas which is widely
planted in production outside was used as the control (cntrl).
2.1.2 Substrates:
The experiments included 5 types of substrates formula of differen mixing ratios.
- Coal (charcoal), pine barks, light stones, volcano foaming slag, Seaweed
2.1.3. Leaf Foliars:
- Including 5 types of fertilizers: Growmore, Hidrophos, Multi K fertilizers,
Striving buffalo, Milo-3 Distribution
2.1.4. Substances capable of regulating the growth(growth regulator):
- DD 1.8 Atonik, ProGibb 10 SP, Dekamon 22.43L
2.1.5. Substance capable of stimulating flowering:
- Asco Gold, RB, AT preparations
2.1.6. Other materials:
- Slow release root fertilizer N: P: K = 14:14:14, wires, Compax bulbs 75W
and 100W, incandescent bulbs 75W and 100W, clamps ruler, tape-measure,
electronic balance, light intensity meter, moisture meter
2.2 Research contents:
2.2.1 To evaluate the growth, development capacities and select some
exotic hybrid orchid cultivars belonging to 3 orchid genera of Cattleya,
Dendrobium, Oncidium adaptable to the North Delta area
2 2.2 Study some technical measures in the nursery stage for some
selected exortic hybrid orchid cultivars belonging to 3 orchid genera of Cattleya,
Dendrobium, Oncidium.

- Experiment 5: Effect of some foliar fertilizer to the growth of the seedlings
at nursery stage.
- Experiment 6: Effect of some growth regulators to the growth of the
seedlings at nursery stage.
2.3.3 The experiments on technical measures in the garden production
stage for the exotic hybrid orchid cultivars belonging to 3 orchid genera of
Cattleya, Dendrobium, Oncidium.
- Experiment 7: Effects of shading system to the growth and development of
selected orchid cultivar Den5.
- Experiment 8: Effect of different types of substrates to the growth and
development of selected orchid cultivar On1.
- Experiment 9: Effect of some foliar fertilizers to the growth and
development of selected orchid cultivar Cat6.
9
2.3.4 Experimental study on some technical measures to control flowering
time for the selected exotic hybrid orchid cultivars of 3 orchid genera of
Cattleya, Dendrobium, Oncidium.
- Experiment 10: To study the effect of types of additional lightings to
flowering and flower quality of orchid cultivars Den5 and On1.
- Experiment 11: To study the effect of additional lighting time to flowering
of orchid cultivars Den5 and On1.
- Experiment 12: To study the effect of additional lighting time combining
with plastic coverage to the ability of flowering to orchid cultivars Den5 and On1
- Experiment 13: To study the effect of flowering stimulants to flowering
capacity of selected cultivar Cat6.
2.4 The observation criteria
2.5 The conditions and equipment applied in experiments

Table 3.1 . Growth characteristics of exotic hybrid orchids at nursery
stage (November, 2006 - Van Giang , Hung Yen, 8 -month-old seedlings)
Criteria
Cultivars
Survival
rate
(%)
Plant
hight
(cm)
No of
stems/
plant
(stems)
No of
leaves
/plant
(leaves)
Leaf
length
(cm)

Leaf
width
(cm)
Soft
rotten

On5 67.5 16.6 3.8 5.4 12.8 1.9 9.3
On6(cntrl) 65.0 12.0 3.0 4.4 9.5 1.1 9.7
CV% 6.2 8.3 7.7 6.6 13.5

LSD
0,05
1.7 0.5 0.6 1.5 0.4

11
Seedlings at the nursery stage of the study, orchids grow well, have high
tillering ability to facilitate growth and development in the future. This proves that
the imported seedlings at the nursery stage perfectly adapted to the ecological
conditions of the Northern Delta area .
3.1.2 Some growth characteristics of exotic hybrid orchid at garden
production stage
Table 3.2. Growth characteristics of exotic hybrid orchids at garden
production stage (December, 2009 - Van Giang, Hung Yen)
Criteria
Cultivars
Plant
height
(cm)
Diameter
(cm)

Den5 42.8 1.9 6.2 29.3 16.8 4.0
Den6 33.6 1.4 4.3 26.0 14.7 4.0
CV% 5.3 10.3 7.3 5.1 6.6 8.3

LSD
0,05
3.7 0.3 0.7 2.5 1.8 0.6
On1 36.2 3.0 4.2 10.6 28.7 2.4
On2 40.2 3.5 5.3 15.9 31.2 3.0
On3 38.9 4.5 6.2 18.8 30.1 4.3
On4 39.6 4.2 5.5 16.3 31.5 4.1
On5 39.6 4.2 5.6 16.6 31.7 4.1
On6 32.3 2.7 4.4 12.5 22.2 2.2
CV% 5.0 6.5 6.8 7.6 5.9 7.8

LSD
0,05
3.3 0.4 0.6 2.1 3.1 0.5
The evaluation on the growth of exotic orchids at mature stage showed that
cultivars Cat6, On1 and Den5 have the best growth indicators.

12
3.1.3 Studying flowering ability of exotic orchids
Table 3.3. Ability of flowering of researched orchids
(December, 2009 - Van Giang, Hung Yen)
Criteria


LSD
0.05
0.2 0.6 0.6
On1 56.7 3.5 117.1 101.1
On2 51.3 2.3 78.7 60.8
On3 43.7 5.6 52.4 44.2
On4 52.0 2.9 84.6 75.6
On5 54.3 3.4 109.3 97.3
On6 51.3 2.0 83.7 72.2
CV% 7.6 7.8 8.5

LSD
0.05
0.4 12.2 11.4

Thus, all orchid cultivars in the orchid group of the research are well capable
of flowering. Depending on the cultivars, number of flowers differs. The number of
effective flowers in Cattleya was from 2.1 to 3.2 flowers/plant , Dendrobium from
5 to 11.3 flowers/plant, Oncidium: from 44.2 to 101.1 flowers/plant.

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3.1.4 Research on quality characteristics of the imported orchid cultivars

Table 3.4 . Some quality characteristics of the orchid flower in the study
(December, 2009 - Van Giang , Hung Yen )

Criteria

Cat7 8.4 8.2 9.0 White Purple No smell
CV% 3.1 3.0 2.7 LSD
0.05
0.6 0.6 0.7

Den1 31.1 8.0 41.7 Whitish Non- aromatic
Den2 26.3 8.4 37.3 Bright pink Non- aromatic
Den3 27.9 8.3 41.0 Whitish purple Non- aromatic
Den4 30.7 8.2 43.7 White, red lip Non- aromatic
Den5 32.4 8.3 54.7 Red Non- aromatic
Den6 22.0 6.7 34.7 Whitish Non- aromatic
CV% 6.7 3.9 5.5 LSD
0.05
3.4 0.6 4.1

On1 32.2 3.63 36.3 Dark yellow Non- aromatic
On2 50.0 3.25 31.3 Dark yellow Non- aromatic
On3 42.0 4.57 24.3
Spotted
Chocolate
Very fragrant
On4 47.0 5.12 33.3 Spotted white fragrant
On5 48.0 5.16 33.7 Fasciated yellow Very fragrant
On6 27.0 3.03 27.3 Dark yellow Non- aromatic

orchids at nursery stage
Table 3:11 . Influence of the seasonal growing time to the growth
of selected orchids at nursery stage (November, 2006 - Van Giang , Hung Yen)

Cultivar Treatment
Survival
rate (%)
Plant
hight
(cm)
No of
stem/plant
(stems)
No of
leaves/plant
(leaves)
CT1 52.7 13.3 3.5 3.5
CT2
74.6 16.5 4.4 4.4
CT3 66.3 14.1 3.8 3.8
CT4 70.2 15.2 4.1 4.1
CV% 2.0 4.9 4.9
Cat6
LSD
0,05
0.6 0.4 0.4
CT1 65.7 17.9 2.4 8.0
CT2
84.0 22.6 3.9 10.4
CT3 73.5 19.1 3.0 8.2

89,3
83,8
89,0
88,0
91,0
70,0
90,0
CT1 CT2 CT3 CT4 CT1 CT2 CT3 CT4 CT1 CT2 CT3 CT4
Cat6 Den5 On1
Tỷ lệ sống (%)

Figure 3.4. The influences of substrates to survival rate and growth
capacity of selected orchid cultivars at nursery stage
Thus, in the nursery stage, the best substrates for Orchid cultivar On1 is:
light stone + pine bark + seaweed (ratio 2:2:1). With this substrate, the survival rate
of On1 is 91%, the plant is fat, healthy, well-developed, the growth indicators are
higher than other treatments.
3.2.3 The influences of foliar fertilizers on the growth of selected orchids
at nursery stage
17,2
18,5
20,3
18,9
24,3
25,6
27,2
26,0
16,6
18,4
19,7

91,7
91,1
97,3
94,7
93,5
70,0
90,0
Cat6 Den5 On1
Tỷ lệ sống (%)
CT1 CT2 CT3 CT4 Figure 3.6. Effect of growth regulators to the survival rate of the selected
orchids at nursery stage

Thus, in the nursery stage, to increase the growth potential for the selected
orchids Cat6, Den5 and On1, spraying Atonik with dosage of 0.1%, 7 days/time
helped seedlings to grow well, increase survival rate, reduce soft rotten disease
incidence, increase plant height and tillering caapacity of seedlings.
3.3 Research on technical measures for the selected orchids in the
garden production stage
3.3.1 Effect of shading measures to the growth, development and quality
of orchid flower Cultivar Den5
3.3.1.2 Effect of shading measures to the ability of flowering of the orchid
Den5
So, with orchid Den5, shading with 2 layer, reflective mesh: 1 fixed layer,
one semi-automatic control layer (light intensity 18000-22000 lux) is most suitable
for summer conditions in the North Delta area that helps the plant to grow and
develop well, increase the ability to achieve higher flowering to 90.7 %, increase
flower length, flower diameter and increase the durability of the flowers. This

CV% 5.9 3.4 2.4
LSD
0,05
0.2 0.8 0.5
Note: CT1 : No cover (cntrl)
CT2: Cover by 1 layer, fixed reflective mesh (22.000 – 28.000 lux)
CT3: Cover by 2layer, fixed reflective mesh (15.000 – 18.000 lux)
CT4: Cover by 2 layer reflective mesh: 1 fixed layer, one layer of
semi-automatic control (18.000 - 22.000 lux)
3.3.2 The influence of substrates to the growth, development and quality
of orchid cultivar On1.
3.3.2.2 Influence of substrate to the flowering ability of orchid cultivar On1
Table 3:23. The influence of substrates to the flowering ability of the orchid
cultivar On1 (December, 2010 - Phu Thuong, Tay Ho, Ha Noi)

Criteria Treatment
Flowering
ability
(%)
Average No of
flower stems /
plant (stem)
Number of
buds /
plant
(buds)
No of Effective

(December, 2010 - Phu Thuong, Tay Ho, Ha Noi)
Criteria

Treatment
Flowering
ability
(%)
Average No of
flower stems /
plant (stem)
Number of
buds /
plant
(buds)
No of Effective
flowers / plant
(flowers)
CT1 (Cntrl) 56.7 1.4 3.3 3.2
CT2 58.6 1.5 3.4 3.2
CT3 57.1 1.5 3.5 3.4
CT4 67.3 1.5 3.5 3.4
CT5 69.5 1.5 3.5 3.5
CT6
73.2 1.6 3.7 3.7
CV% 6.3 5.8 5.6
LSD
0.05
0.2 0.4 0.3
Thus, it can be seen that foliar fertilizers affected the ability of flowering of
orchids Cat6. Fertilizer Hydrophos (CT6) with dose of 0.1%, spraying 1 time/week

flower stems /
plant (stems)
Number
of buds /
plant
(buds)
No of Effective
flowers / plant
(flowers)
CT1
(Cntrl)
16.2
1.3
10.7 9,5
CT2 33.3 1.3 11.3 10,3
CT3 40.5 1.3 11.7 10,7 Den5
CT4
58.5 1.4 12.5 12,0
CT5
59.3 1.4 13.0 12,5
CV% 0.8 1.0 1.0
LSD
0.05
0.2 0.2 0.2
CT1
(Cntrl)
23.0

use of incandescent light bulbs is more efficient as compared with Compax bulbs.
20
3.4.2 Effect of additional lighting time on the growth, development of
Den5 and On1.
3.4.2.2 Influence of additional lighting time to flowering ability of orchids
Den5 and On1.
Additional lighting time from 45-60 days, 4 hours per day (18 - 22h) with
75W incandescent lamp, density of 1 lamp/ 4m2 in winter conditions of the North
Delta area would help orchid Den5 and On1 to grow and develop better, improve
flowering ability, bud formation and promote the ability to bloom effective,
particularly increases flower quality, flower long lasting durability.
Table 3:31. The influences of additional lighting time to flowering capability of
orchid cultivars Den5 and On1 (March, 2011 - Van Giang, Hung Yen)

Criteria Treatment
Flowering
ratio (%)
Average
number of
flower stems/
plant (stems)
Number
of buds /
plant

3.4.3 To study the effect of additional lighting time combining with plastic
cover to the flowering abilities of Den5 and On1 cultivars.
Thus, the application of additional lighting for 45 days, 4 hours per day
(from 18 - 22 pm with a 75W incandescent lamp, density 1 bulb/4m
2
) in
combination with plastic cover in the northern winter conditions of our country has
made positive effect on the ability to flower and orchid flower quality of On1 and
Den5 cultivars, markedly increases the rate of flowering plants, increasing the
number of buds, number of flowers, the indicators of quality, flower durability.
Especially to cultivar On1, all indicators in flower quality increased significantly in
treatment of additional lighting plus plastic cover.

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Table 3:33. The influence of additional lighting time in combination with plastic
cover to the ability to flower of Den5 and On1 cultivars
(March, 2011 - Van Giang, Hung Yen)
Criteria Treatment
Flowering
ratio (%)
Average
number of
flower stems/
plant (stems)

0.4 12.4 11.1
Note: CT1 (cntrl): No additional lighting
CT2: 45 days additional lighting by incandescent lamp 75W (from 18h - 22h)
CT3: 45 days additional lighting by incandescent lamp75W (from 18h - 22h)
in combination with plastic cover.
3.4.4. Studying the effect of flowering stimulants to flowering and flower
quality of the cultivar Cat6
For orchid Cat6, using flowering stimulants HVP (Treatment 3) in condition
of the Northen Delta area has increased flowering percentage (88.8%), and
remarkablly increased the indicator of flower quality as increasing flower length,
flower diameter and natural durability of flowers.
Table 3:35. The influence of flowering stimulants to flowering capacity
of orchid cultivar Cat6 (March, 2011 - Phu Thuong, Tay Ho, Ha Noi)

CriteriaTreatment
Flowering
ratio (%)
Average
number of
flowering
stems/ plant
(stems)
Number of
buds / plant
(buds)
Number of
effective

Price
(VND
/plant)
None
flowering
plant s x
cost
Revenues
(VND)
Total
expenses
(VND)
Profit
(VND)
Efficienc
y (times)
CT1
(cntrl)
100 57 160,000 2,580,000 11,700,000 6,250,000 5,450,000 1
Cat6
CT2 100 89 160,000 660,000 14,900,000 6,412,000 8,488,000 1.56
CT1
(cntrl)
100 17 65,000 2,905,000 4,010,000 3,750,000 260,000 1
Den5
CT2 100 70 65,000 1,050,000 5,600,000 3,973,000 1,627,000 6.26
CT1
(cntrl)
100 24 75,000 3,040,000 4,840,000 4,250,000 590,000 1
On1

23
comparing with the control treatment. With orchid On1and Den5, the economic
efficiency increased significantly when using additional lighting measure
combining with plastic cover, specifically: to orchid Den5, the efficiency increased
by 6.26 times as compared with no additional lighting and plastic cover, to On1 the
efficiency increased by 3.41 times as compared with the control treatment.
Thus, the application of techniques for selected orchids has brought about
remarkable economic efficiency. The results of this study help orchid growers as a
base to apply and invest in developing selected orchid cultivars.

CONCLUSIONS AND RECOMMENDATIONS
Conclusion

1. Through the results of survey and evaluation on criteria of growth,
development and quality of some imported orchid flowers of 3 genera of Cattleya ,
Dendrobium and Oncidium at the nursery and garden production stages, 8
promising orchid cultivars have been chosen, adaptable to ecological conditions of
the Northern Delta region: 3 cultivars of the genus Cattleya are Cat1 (Cattleya
ploenpit golden delight), Cat3 (Cattleya netrasiri green) and Cat6 (Cattleya
haadyai delight); 3 cultivars of genus Dendrobium are Den1 (Dendrobium Big
white sanan), Den4 (Dendrobium charming white) and Den5 (Dendrobium cherry
red), 2 varieties of the genus Oncidium are On1 (Oncidium Aloha Iwanaga), On5
(Oncidium (Agnole x Manilatum). The above mentioned cultivars have good
characteristics such as good stability, good growth and development, strong
tillering, high flowering rate, good flower quality, long lasting flower durability
with resistance to pests and diseases harmful insects These orchi cultivars can
meet the requirements of the breeding new orchid cultivars for production.