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 - 2014
Project completed at:
VIETNAM ACADEMY OF AGRICULTURAL SCIENCES
Scientific supervisors: 1. Ass. Prof .Dr. Nguyen Thi Kim Ly
2. Prof. Dr. Nguyen Xuan Linh
Critic 1:
Critic 2:
Critic 3:
The thesis is defended at Council for Thesis Assessment at University/
Institutional level, held at:
Vietnam Academy of Agricultural Sciences
At hours, day month year
This thesis can be referred to at:
- Vietnam National Labrary
- The Libray of Vietnam Academy of Agricultural Sciences
1
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 - 380C), high humidity and high sunlight intensity that causes a
negative impact to the growth of the plants, making the plants susceptible to leaf
blight, high percentage to rotten disease prevalence. In Winter, the temperatures is
too low, weak sunlight intensity, short sunlight during the days are also not
favorable for plant growth , development and giving flowers. On the other hand, as
for lack of good seeds, technical inconsistency and inappropriate caring process ...
the production cuold not bring about high efficiency, quantity and quality of
orchids still can not meet consumer requirements, while the demand for the above
mentioned orchids is very high. In order to overcome this limitation, enabling plant
orchids in general and Cattleya, Dendrobium and Oncidium orchids in particular to
2
develop to be effective, the research subject " Studying the growth, development
and technical measures to increase productivity, quality of exotic orchid varieties
(Cattleya , Dendrobium , Oncidium ) for Northern Vietnam . "
2. The purpose and requirements of the subject
2.1. Purpose
- The purpose of this research subject is to study the growth, development of
some exotic hybrid orchid genera of Cattleya, Dendrobium, Oncidium in order to
select new promising hybrid orchid cultivars, consistent with the Northern Delta
region and the nearby region with similar ecological conditions.
- To determine the impact of growing conditions and technical factors to the
growth, development, flowering of some exotic hybrid orchid genera as Cattleya,
Dendrobium, Oncidium and to propose appropriate technical measures, applying
effectively to production that contribute to the development of growing orchids in
the Northern Delta.
2.2. Requirements of the research subject:
- 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
growth, development and the proportion of bearing flowers for these newly
selected orchid cultivars. These technical measures are of high feasibility, high
application capability to mass production that bring about highly practical
effectiveness for growers.
3.3 The Novelty of the thesis
- Having fully and systematically studied the morphological characteristics ,
growth and development for an orchid to gain high yield and quality. On that basis,
3 hybrid orchid cultivars of Cattleya, Dendrobium , Oncidium with good prospects
for growth, development, good flowering in the condition of Winter - Spring
season in the Northern Delta region, have been selected for the production of
hybrid orchids.
- Having studied systematically the growing conditions and technical
measures for eachcrop season for 3 orchid genera of Cattleya orchid, Dendrobium,
Oncidium, in order to increase survival rate of seedling and to reduce the incidence
of soft rotten disease in nursery stage in hot and humid summer climate condition.
At the same time, it helped to increase the rate of flowering of the plants as well as
flower quality blooming in cold winter conditions of the Northern Delta region .
4. The structure of the thesis
The main contents of the thesis are presented in 139 pages (excluding
references and appendices). Introduction: 4 pages; Chapter 1: Overview document:
40 pages, Chapter 2: Materials, research content and methodology: 17 pages;
Chapter 3: Research Results and Discussion: 76 pages; Conclusion and proposals: 2
pages. The dissertation consists of 37 tables, 19 form, 50 Vietnamese documents,
72 documents in English. The appendix includes photos of selected orchids in the
experiments, statistical analysis results and experimental data processing and
contents related to the thesis.