Plant Genetic Resources Diversity and Seed Supply Systems in Nan,
Thailand |
The objectives of this study were to determine the
extent of crops diversity, the extent of plant genetic erosion, current
seed supply systems and indigenous conservation and development methods
employed by farmers in Nan province in Northern Thailand. The study
focused on rice and some vegetable species, namely: chili, egg plant,
squash, bottle gourd, sponge gourd, bitter gourd and lima bean. The data
were gathered by means of an area survey and by interviews of selected
farmers most of whom were males between 30 and 75 years old.
A substantial variation exists in all crops studied, as
indicated by the number of varieties identified in the area. In total, the
number of varieties identified amounted to 74 lowland rice, 148 upland
rice, 56 chili, 47 eggplant, 19 pumpkin, 15 bottle gourd, 7 bitter gourd,
17 sponge gourd, and 27 lima bean varieties.
Only 23 rice varieties were reported to have
disappeared. This forms about 10% of the rice varieties still existing.
Respondents made no mention of any variety of other crops having
disappeared.
|
Background
During the past three decades, the major objective
guiding the development work undertaken by the Thai government is the
promotion of export-oriented agriculture production. This development
paradigm arose when Green Revolution technology became available in the
mid-1960s. Agricultural production, it was predicted, would bloom in a
Green Revolution where farmers would have regular, consistent access to
required resources for the production of high yielding crop varieties.
These resources included supply of seeds, water, chemical fertilizers,
pesticides, germicides, herbicides and machinery. Two decades went by, and
many unforeseen problems associated with the Green Revolution technology
cropped up, most notably degradation of the environment, emergence of more
destructive and resistant strains of pests and diseases, and erosion of
genetic resources.
This experience led many NGOs, educational institutes,
and some GOs to formulate a new holistic development model which focuses
on developing capacities of local people to better meet their own needs
through self - reliant local efforts. Conservation and development of
plant genetic resources is one of the strategies to fit in this
development model.
The Nan CBDC project conducted the survey to analyze
the situation regarding plant genetic resource (PGR) in the area. The
results of the study will be used as base line from which to set up future
project activities. The survey was conducted throughout Nan province from
November 1996 to January 1997.
Research Site
In general, the cropping systems in Nan can be divided
into two types, namely monocropping system and mixed cropping system. The
monocropping system is increasing every year and involves lowland rice,
high yielding varieties of field crops, vegetable crops and commercial
fruit trees. However, the majority of farmers still practice mixed
cropping. In this system, farmers prefer to use traditional varieties.
They grow many kinds of crops in the same area combining upland rice with
chili, eggplant, groundnut, bean, banana and some fruit trees.
Objectives of the Survey
- to identify the status of diversity and extent of plant genetic erosion of indigenous rice and some vegetable species;
- to examine the formal and informal seed supply system;
- to examine local practices of plant genetic conservation;
- to examine farmers’ methods on crop development in Nan province.
Scope of the study
The survey on PGR diversity and seed supply systems
focused on lowland rice, upland rice, chili, egg plant, squash, bottle
gourd, sponge gourd, bitter gourd, and lima bean.
Organization of the study
The study was coordinated from the office of the Nan
CBDC Project at the Rajamangala Institute of Technology at Nan Campus. The
survey and interviews were carried out throughout Nan province.
Respondents
There were 983 respondents interviewed. The farmer
respondents grew any of the crops mentioned above and were selected
because they expressed willingness to join the crop diversity study.
Collection of data
Data were gathered by means of interviews and field
observations. The project’s interviewers went to every farm and used a
set of guidelines in the collection of data. The data were separated into
groups according to specific objectives of the study. Frequency counts and
percentages were used in analyzing and presenting the data.
Respondents’ Profile
Eighty percent of the farmer respondents were males.
Their age ranged from 30 to 75 years of which 87 % belong to age bracket
of 30 to 50 years. Most of the respondents were male because it is a rural
tradition that men are responsible for all hard work that need physical
strength such as farm duties. Formal deals with outsiders are also the
responsibility of the male, except for families without male. The
respondents were more than 30 years old, because majority of the young men
were in schools, and some younger people went to other areas to find
higher earning jobs.
About one-half of the respondents obtained their major
income from field crops and more than one-fourth obtained theirs from rice
production. Only few obtained their income from fruit crops. The rest
obtain their income from other sources.
PGR Diversity
Crop Distribution and Use
Nan province is located in the mountainous northern
region where irrigation system are hardly available. The major
agricultural areas are located in Maecharim, Muang, Santisuk and Thawangpha.
The Land Development Department classified the
ecosystems into 3 based on the elevation in meter above mean sea level (masl)
namely; (a) lowland (<350 masl); (b) upland ( 350-700 masl); and (c)
highland (>700 masl). The distribution of lowland and upland rice
varieties in different ecosystems is listed in the table:
Distribution of lowland and upland rice varieties
|
Crops |
Ecosystem |
No. of Varieties |
|
Lowland Rice
|
Rainfed |
72 |
|
f
|
Irrigated |
2 |
|
f
|
Total |
74 |
| f |
f
|
f
|
|
Upland Rice
|
Upland |
33 |
|
f
|
Highland |
209 |
|
f
|
Total |
242 |
Lowland rice is grown in a wide range of agroecosystem
- from the flood plain in lowlands to the terraced paddy fields in
highlands. Most of lowland rice (93.24%) is grown in rainfed area, and
only 7 % is grown in irrigated fields.
Upland rice varieties are found in upland (86.36%) and
highland (13.64%) areas such as Bokleu, Chiangklang, Pua, Songkwae and
Thungchang. These areas are inhabited by native people who prefer
glutinous and aromatic rice, thus almost all upland rice is glutinous and
aromatic.
The vegetable crops in this study are grown in all
ecosystems. In general, the Upland and highland ecosystems have a higher
number of varieties, and are therefore more diverse than the lowland
ecosystem.
Number of vegetable crop varieties in different
ecosystem
|
|
Ecosystem |
|
|
Crop |
Lowland |
Upland |
Highland |
Total |
|
Chili |
12 |
29 |
16 |
57 |
|
Eggplant |
15 |
32 |
29 |
76 |
|
Bottle gourd |
9 |
8 |
5 |
22 |
|
Bitter gourd |
2 |
5 |
5 |
12 |
|
Sponge gourd |
10 |
18 |
21 |
49 |
|
Pumpkin |
7 |
14 |
14 |
35 |
|
Lima bean |
8 |
16 |
12 |
36 |
Number of crop varieties determined to be existing
|
|
|
Number of Varieties |
|
Crops |
Existing |
Lost |
|
|
HYV* |
TV** |
Total |
|
|
Lowland rice |
7 |
67 |
74 |
2 |
|
Upland rice |
0 |
148 |
148 |
21 |
|
Chili |
0 |
56 |
56 |
0 |
|
Egg plant |
0 |
47 |
47 |
0 |
|
Pumpkin |
1 |
19 |
20 |
0 |
|
Bottle gourd |
0 |
15 |
15 |
0 |
|
Sponge gourd |
0 |
27 |
27 |
0 |
|
Bitter gourd |
0 |
7 |
7 |
0 |
|
Lima bean |
0 |
27 |
27 |
0 |
|
*High yielding varieties |
|
**Traditional varieties |
Chili peppers are grown in all areas of Nan, because
chili is regarded a necessary ingredient in the local diet, except for
some small groups of hill tribes. Chili pepper is usually found in
highlands, because it cannot tolerate flooding.
Egg plant is also common in most parts of Nan, because
it is extensively used in local meals. Like pepper, it has no tolerance to
flooding and thus planting is mostly in upland and highland areas.
Bottle gourd is mostly grown for home use, and seldom
transported to other places for sale because it is planted for home
consumption in almost every farm. It is mostly grown in the lowland area
because of its high water requirement. About three quarters of bottle
gourd production is consumed and the rest is used as containers.
All bitter gourd varieties are tolerant to drought, and
are therefore usually found in upland and highland areas. Most of them are
wild or semi-domesticated varieties, which grow naturally in garden or
field margins. Farmers used to collect bitter gourd fruits from natural
areas for home consumption and for marketing.
Most of the sponge gourd varieties are grown in upland
and highland areas; some upland rice farmers grow sponge gourd in some
part of their rice fields, or mixed with their rice crop.
Squash and lima bean are grown for family consumption
in every district of Nan. Although squash could grow in every ecosystem,
most of them were found in highland and upland areas
Lima bean is also grown for consumption, mostly found
in upland and highland areas but rarely in lowland areas.
Crop Diversity
A considerable variation in all crops studied was
observed, as indicated by the number of varieties identified in the area.
There were 74 lowland rice, 148 upland rice, 56 chili, 47 egg plant, 15
bottle gourd, 27 sponge gourd, 7 bitter gourd, and 27 lima bean varieties
identified. Most of these were farmers’ or traditional varieties. Only 7
lowland rice and 1 squash varieties were formally released HYV’s.
Lowland and upland rice
Many characters of both lowland and upland rice were
found to be variable although some traits occurred at high frequency.
Traits occurring with high frequency in both types of rice were medium
height, exhibited resistance to diseases and pests. The very high
frequency of glutinous character, lack of awns, and resistance to pest and
diseases implies that farmers in the areas preferred and have selected for
these characters. A very small number of both lowland and upland varieties
were observed to be early maturing.
The different varieties of vegetable crops in this
study exhibit diverse traits. Some traits occur at higher frequencies
indicating some degree of natural or intentional selection for these
traits.
Chili.Most varieties of chili are medium to
strongly pungent or spicy, and of medium height. About one-half of chili
varieties were resistant to pests and diseases. Farmers prefer these
traits. The high frequency of varieties possessing these traits is most
likely a result of farmer selection.
Eggplant. Traits that occur at high frequency are
the ones with fruit tip in downward direction, medium fruit length, green
color of immature fruits and an elongated shape. These characters are
preferred in the market.
Bottle gourd. Traits that occur at high frequency are smooth skin
texture, long vines, and medium maturity. Forty percent of bottle gourd
varieties were of small fruit size, 33% were medium, and 26.67% were
large. About three-fourths (73%) of bottle gourd varieties were used for
home consumption, the rest (26%) were used as containers. These
characteristics were suitable for home cooking and marketing
Bitter gourd. More than half of bitter gourd
varieties were of medium fruit size. All varieties have long vines. More
than two-fifths exhibited smooth fruit skin texture. The rest had ridges
or have rough texture. Most (71%) varieties were of medium maturity.
Sponge gourd. The predominant traits in sponge
gourd were long vines, medium maturity, smooth fruit skin texture and
medium size. Farmers and consumers prefer these characters which are
similar preference for most gourds.
Squash. The predominant traits in squash
include small to medium fruit sizes, long vines, yellow color of mature
fruits and sweet and sticky fruit flavor. Two-fifths (40%) of squash
varieties were susceptible to fruit worm and one-fourth (25%) was
susceptible to leaf cutter, 35% are resistant to a biotic stress, but the
rest (20%) had no specific characteristic.
Lima bean. The fruit character of lima bean exhibit
a very high degree of variability. Many variation were observed for pod
shape, size, color, and number of seed. The traits with high frequency
included round, flat and long pod, medium pod size 5-6 seeds per pod, and
green immature pod color. All lima bean varieties were sweet and are late
maturing.
Reasons for choosing crop varieties
|
Reasons |
No. of Respondents |
% |
|
Gastronomic |
947 |
96 |
|
Morphological |
29 |
3 |
|
Agronomic |
3 |
0.5 |
|
Socio-economic |
4 |
0.5 |
|
Total |
983 |
100 |
Seed Supply Systems
The survey showed that 81% of farmers obtained seeds
from their own farms, whereas some of them (10%) obtained seeds from other
farmers, only a few (9%) obtained seeds from the formal system. A majority
(96%) of respondents chose crops varieties for the best gastronomic
characteristics. Only a few cited a combination of morphological,
socio-economic and gastronomic characteristics, as their main reasons for
choosing a variety.
Sources of seeds
|
Seed Sources |
No. of Respondents |
% |
|
Own farm |
800 |
81 |
|
Other farm |
100 |
10 |
|
Institutions |
83 |
9 |
|
Total |
983 |
100 |
Crop Conservation Methods
Crop conservation includes selection, harvesting,
processing and storage of seeds. Generally, after seeds are collected they
are cleaned and dried prior to storage. In some cases, seeds are removed
from the fruit before drying and storage such as in eggplant, chili, and
squash. In some cases, the whole fruit is dried and stored. In the
countryside, farmers have separate storage houses for their seeds. Some
valuable seeds (like for rice), however, are kept in the house.
More than one-half (54%) of lowland rice farmers stores
rice seeds inside their house, whereas one-third (31%) keeps them in
separate storage houses. The rest store their seeds in special containers.
Three - fourth (74%) of upland rice farmers keep their seeds in storage
rooms. The large majority of chili, eggplant, squash, sponge and bitter
gourd farmers keep seeds in storage rooms and only a few store their seeds
in other places. Almost two-fifths (37%) of bottle gourd farmers keep
their seeds in storage rooms, and more than one-third (34%) keep them in
specialized container, the rest (28%) store in the other places.
Crop conservation is mainly the responsibility of male
farmers, or a shared activity between husband and wife. Occasionally, the
wife is involved in conservation.
For lowland and upland rice, about half of the
respondents consider absence of disease as the major selection criterion.
The rest of the farmers select their varieties on the basis of healthy
seeds and panicle length.
The study revealed a considerable amount of diversity
for the focus crops. All of these crops are grown mainly for home
consumption, thus, farmers’ personal preferences determine their choice
of varietal characters. This is reflected in the predominant traits
observed among the existing varieties. Some traits, however, occurred at
high frequency among the present crop varieties, although farmers were not
interested in them.
Farmers’ common practice of mixed cropping has
maintained diversity for many years. Only rice is grown extensively in
large areas. Vegetable crops are grown in small home gardens where various
crops and varieties can be found. Even some portion of the rice fields is
grown with vegetable crops simultaneous with rice cropping.
Farmers in the area have full control over their seed
supply. Farmers obtain seeds from their own farm and maintain them in
their own house or special storage area until the next cropping season.
Some seeds exchanges between farmers occur, but very few get their seeds
from the formal seed supply system.
Introduced varieties of rice such as RD2, RD6, RD8, IR258, etc. did not
replace the local varieties of rice in some areas. We suggest further
study on the reasons why farmers maintained the local varieties, and the
factors influencing their choice of varieties.
Genetic erosion is not a serious problem in the study
areas. But it may occur in the very near future as the Thai government
embarks on massive introduction of HYVs throughout the country. We suggest
raising the awareness of the farmers concerning PGR diversity conservation
in the CBDC Nan project area.
During the survey, we identified active farmers who
were interested in breeding and maintaining many vegetable and rice
varieties. It will be highly productive and informative to work with these
farmers as partners. Their indigenous knowledge in germplasm conservation
and crop improvement can be utilized and strengthened in the process.
We need to conduct training to improve farmers' skills in seed processing and seed storage.
Work on PGR conservation and other community
development process need to be linked with sustainable agriculture.
Nan Provincial Office. 1996. Data base of Nan Province, Thailand
Soonthornmuang, Sathien. 1990. Document of Basic Technical Rice
Production. Rajamongkol Technological Institute, Nan Campus. Thailand
|
|