Methodologies for Strengthening Informal Indigenous Vegetable Seed
Systems in Northern Thailand and Cambodia
A. Bicksler, R. Bates, R. Burnette, T. Gill, L. Meitzner Yoder, and Y. Srigiofun
International Sustainable Development Studies Institute
Chiang Mai, Thailand
Department of Horticulture, The Pennsylvania State University
University Park, Pennsylvania, USA
ECHO Asia Regional Office
Chiang Mai, Thailand
Office of International Programs, The Pennsylvania State University
University Park, Pennsylvania, USA
International Sustainable Development Studies Institute
Chiang Mai, Thailand
Faculty of Agricultural Production, Maejo University
Sansai, Thailand
Keywords: seed systems, germplasm conservation, village surveys, seedbank, value
chain, seed viability, preservation
Abstract:
Informal seed systems provide access to locally-adapted indigenous crops and
constitute an essential component of sustainable production for resource-poor
farmers in Southeast Asia. Research conducted with five ethno-linguistic groups in
twelve villages in northern Thailand and Cambodia focuses on strengthening the
indigenous informal vegetable seed system, including the conservation of knowledge
surrounding that system. Through targeted village surveys and using photo card
sorts to standardize responses across languages, our methodology documents and
characterizes seed system species, pathways, and “germplasm gatekeepers” for
indigenous annual and perennial vegetable crops important to northern Thailand
hilltribe and Khmer communities. Additionally, farmer-innovated seed preservation
and storage methodologies are documented, and farmer-saved seeds are tested using
a village-based photovoltaic-powered growth chamber to determine baseline seed
viability and vigor under local conditions. At the culmination of research in village
clusters, seed and information exchange events occur that facilitate the inter-village
exchange, preservation and dissemination of important genetic resources and best
practices for seed saving and storage methodologies identified during the farmer
community surveys. When our research is completed in eight Northern Thai villages
(February 28, 2011) and in four Cambodian villages (March 30, 2011), we will have
built linkages between under-represented Southeast Asia farmers of diverse
ethnicities, a local innovative seed bank (ECHO Asia Regional Office), and a local
university extension training system.
INTRODUCTION
Seed is a fundamental agricultural input and access to locally-adapted, quality
seed is an essential component of sustainable crop production. In much of the developing
world, informal seed systems provide access to locally-adapted indigenous crops and
constitute an essential component of sustainable production for resource-poor farmers
(Almekinders et al., 1994; Thiele, 1999; Seboka & Deressa, 2000). Indeed, planted seed
in many regions of the world are not improved varieties, but come from farmer-to-farmer
seed exchanges or from farmer self-saved seed and often comprise the majority of planted
acreage (Meredia et al., 1999). This local seed production and distribution facilitates
maintenance of crop bio-diversity by preserving in situ locally adapted and often
underutilized varieties and by broadening the genetic base of production with multiple
varieties adapted to specific production systems and micro-climates (Louette et al., 1997;
Van Dusen, 2000; Bellon et al., 2003). These informal seed systems are also critical for
seed and food security during periods of instability or natural disaster, including changing
environmental conditions (Chapman et al., 1997).
Current efforts to identify, conserve, improve and disseminate this rich genetic
resource are insufficient (Smale and Bellon, 1999; Mazhar, 2000; Maxted et al., 2002).
The mechanisms and pathways of informal seed systems by which farmers acquire new
varieties are not well documented or well understood. Much of the indigenous
germplasm represented in informal seed systems has not been sufficiently characterized,
improved, preserved, or widely distributed (Sperling and McGuire, 2010). Little effort
has been made to develop value chains around locally important species to enhance
resource-poor household income. The local informal seed systems also usually lack the
means to disseminate these resources regionally, thus limiting the reach of their benefit.
The opportunities to characterize these crops for traits of interest such as drought
tolerance or disease resistance are decreasing as these landraces are lost or replaced in
farmer fields and in local diets (Bellon, 2004).
A rich diversity of indigenous germplasm exists in Southeast Asia and represents
a valuable resource for the development and improvement of crop species locally,
regionally and globally (Rerkasem et al., 2009). Annual and perennial vegetables in this
region are grown primarily in mixed home gardens and used abundantly, both raw and
cooked in local dishes. Local vegetable varieties are mostly grown for home
consumption, but increasingly over the past decade are also found in urban markets. The
high diversity of ethnic groups within a small region has produced extraordinary diversity
in indigenous vegetables as different groups favor specific culinary and agronomic
qualities. Local seed systems are thus critical in the maintenance of crop diversity,
transfer of knowledge and species and sustainability of these ecosystems.
With funding from USAID’s Horticulture Collaborative Research Support
Program, methodologies were conducted to strengthen indigenous seed systems in eight
northern Thai and four Cambodian communities. This research was conducted to provide
proof of concept for the development of a prototype whereby local farmers and noncommercial seed traders are linked to an innovative seed bank and developing markets,
and supported by accessible information made available through a local outreach
network.
Although attempts to document seed varieties, pathways and other parts of the
seed system have been conducted across the world (Louette et al., 1997; Mazhar, 2000;
Seboka and Deressa, 2000), this research extends these approaches into a holistic
appraisal of the informal seed system in northern Thai and Cambodian communities. Such
an approach demonstrates the value of investing in local, indigenous informal seed
systems, as it leads to an optimization of the functionality of the system, providing
multiple benefits beyond simply the local communities directly involved.
MATERIALS AND METHODS
The project uses mixed quantitative and qualitative methods, to optimize data
triangulation on multiple complex topics (Table 1). Supported by regular visits from
academic supervisors, the field research team consisted of one local village resident; one
foreign research coordinator; and two national graduates of the regional agricultural
university. Researchers employed three approaches: photo card sorts with small groups;
household interviews and observations with wealth-stratified samples; and inter-village
seed swaps to foster information exchange and discussion among different villages.
In order to develop a common baseline vegetable vocabulary useable to
standardize responses across multiple language groups, half-page picture cards of 77
regionally important annual and perennial vegetable species were produced. The cards
were a half-sheet in size, with a color photograph of the plant, its edible vegetable parts
and/or seeds, which enable villagers to recognize the species. The front of the card has
large numbers to identify each species, which helps researchers easily record the data, and
the back of the picture lists the species name in Latin and six other languages. Groups of
6-10 villagers sorted these cards to yield quantitative measures that are comparable across
sites, including species presently available in the village; plant parts eaten and methods of
preparation; and sources from which villagers buy or trade their seed for a given species,
rather than producing their own. Card sorts proved time-consuming in the village
context, so field researchers modified the sorts to identify those species present in the
village (approximately 50 species from preliminary results in one region), and then
gathered additional data on agronomic factors and seed practices using a species-byspecies discussion on those that are present in the village.
Card sorts are complemented by targeted, semi-structured interviews and
observation at the household level. Since household wealth is a critical factor in seedsaving practices (Badstue et al., 2006; Louette et al., 1997; Sperling and McGuire, 2010),
researchers used village mapping to conduct empirical wealth assessments alongside
villagers to derive a three-tiered wealth ranking of each household in the village.
Interviews of at least 10% of each village’s households were then conducted in a 2-1-2
wealth stratification, producing relatively greater sampling of wealthy and poor
households to identify any differences in seed access and saving. Interviews were
conducted in each home to permit observation of seed-saving practices and ready access
to stored seeds and species growing in home gardens. In these interviews, the photo cards
also proved extremely useful in identifying species for which farmers and researchers
used different names. Interviews covered specific examples of novel and annual seed
acquisition, seed trade pathways, and seed selection and saving practices.
In addition to targeted village surveys and picture card sorts, farmer-innovated
seed preservation and storage methods were recorded in each of the village clusters.
Beginning on January 4, 2011, households that were identified during the village card
sorts were visited for more in-depth interviews over 2 weeks and as an opportunity to
acquire farmer-saved seeds for the ECHO Asia Regional Office Seed Bank and research
purposes. The ECHO Seed Bank is an innovative facility located in Mae Ai, Thailand that
evaluates, produces, and distributes underutilized crop species seed in an effort to help
develop farmer-market-seed bank linkages. Four villages were selected in each of three
village clusters, and at least 10% of the households were interviewed in each village.
During the interview, households were asked to share about their various indigenous
vegetable seeds, donate seeds to the seed bank and research project, and describe their
seed preservation and storage methods for all seed lots donated. Researchers asked for
typical seed that farmers would plant in their field as a way to acquire a representative
sample of farmer-selected germplasm from donors. Each seed lot was identified by a
particular accession number, and the following data were collected for each accession: 1)
household name; 2) village cluster; 3) village name; 4) ethnicity; 5) wealth index (based
upon same parameters as established for the village card sorts); and 6) sample collection
date. In addition to the donor information, accession information for the seed lot was also
collected and consisted of: 1) a reference card number from species in the card sort that
the household could positively attach to donated seed; 2) Latin binomial, if available; 3)
local plant and variety name; 4) approximate harvest date; 5) any seed treatments to the
seed lot before storage; 6) storage method; 7) storage location; and 8) the number of seeds
received for each seed lot. The seed treatment, seed storage method, and seed storage
location data were analyzed by frequency for accessions, varieties, and households.
After sorting and discarding diseased or damaged seeds for each of the seed
accessions collected, 25% were stored in paper packets to be taken to the ECHO Asia
Seed Bank in Mae Ai, Thailand, for further identification, evaluation, and potential growout and distribution; 50% were designated as seed material to be used in a seed viability
experiment; and 25% were stored in paper packets to be used in a seed vigor experiment
at the ECHO Asia Seed Bank. The minimum usable number of seeds per accession was
forty and the maximum usable number of seeds per accession for the viability experiment
and vigor experiments were 200 and 50, respectively. Any additional seeds above this
threshold were added to the ECHO Asia Seed Bank portion.
A seed viability experiment was conducted at the village-level to procure real-time
germination data while the social surveys were being conducted and to stimulate interest
in simple research methodologies within the village. A seed germination cabinet was
constructed using an aluminum kitchen cabinet (122 cm tall, 77 cm wide, and 41 cm
deep) insulated with foam sheets. Constant temperatures (28-30C) (Kemble and
Musgrove, 2006) and high relative humidity suitable for seed germination were achieved
by using two 10W florescent ballasts and tubes (Philips, 10W/T8/DL Daylight, 6500K)
attached to the tops of both shelves in the cabinet and powered with a 120W solar array
connected to a deep-cycle battery and DC-AC inverter. A simple fifteen-minute
increment timer provided modulation of the on/off cycle for the florescent tubes to
achieve constant temperature and relative humidity.
The petri dish method of seed germination was modified from Ellis et al. (1985),
and Rao et al. (2006), but retained the general methodology of using petri dishes and
absorbent paper as a substrate. A randomized complete block design with two
replications (Rao et al., 2006) was used for the seed viability experiment. Because of the
fluctuating numbers of seeds per accession and the relatively small amount of seeds we
thought we would receive from donors, it was decided that the guidelines proposed by
Rao et al. (2006) would be followed to create a baseline standard of viability for each
accession received. Seed accession was the treatment and seeds within treatment were
subsamples. Treatments were randomized within replications, and replications were
divided among the two shelves of the germination cabinet to account for environmental
variability.
On January 13, 2011, plastic, disposable petri dishes (9.5cm by 6cm small size;
11.5cm by 8cm medium size; and 13cm by 9.5cm large size) were lined with folded,
unused paper towels, and an aliquot of 6mL, 8mL, and 10mL (small, medium, and large,
respectively) was given to each petri to moisten the paper towel. All seed treatments were
soaked in a 1% sodium hypochlorite solution for 3 minutes (small seeds) or 5 minutes
(larger seeds), decanted, and rinsed with six changes of distilled water before being plated
onto the paper towels in each petri (Rao et al., 2006). Forceps were used to evenly
distribute seeds across paper towels to ease checking for germination and to reduce
possibility of contamination. Petris were labeled, wrapped loosely in a plastic sandwich
bag, and randomized within each replication in the germination chamber. Seed
germination was considered radicle emergence (Ellis et al., 1985). Seeds were checked
for germination one day after beginning the experiment and then every-other-day,
removing and recording the number of germinated seeds. Every two days, aliquots of
3mL of water (large petris), 2mL of water (medium petris) and 1mL of water (small
petris) were given as needed to maintain moist conditions of the substrate. Decaying
seeds were promptly removed and recorded as non-germinated to prevent contamination;
in the event of increasing contamination, all seeds were removed from a particular petri
dish, soaked in 1% sodium hypochlorite like above, and re-plated on a new paper towel
and petri dish (Rao et al., 2006, University of Hawaii, 2007). Seed viability as percent
germination and mean time to 50% germination were calculated for each treatment. Seed
accessions can then corroborated using the accession data to pinpoint farmers and seed
preservation and storage methods that result in high seed viability and vigor. Follow-up
research will determine what seed preservation and storage methods help to contribute to
high seed viability and vigor. Accessions of similar commercially available seed to the
village-collected seed will be subject to a similar seed germination experiment at the
ECHO Asia Seed Bank in April 2011, to compare this seed to farmer-saved, preserved,
and stored seed received during the village trials. Additionally, vigor experiments will be
conducted at the seed bank using potting mix and the 25% of the seed lots put aside for
vigor determination.
RESULTS AND DISCUSSION
Preliminary results evidence the data richness from combining agronomic and
socio-economic research. Interviews indicate that while the region does not appear to
have specialized seed provider individuals, seed saving is far more frequent and important
among poor households than the wealthier households with greater access to commercial
seed. Purchased seed carries greater prestige than home-saved seed. Seed trading
pathways are also more confined to ethnic lines than anticipated, with just a few reported
cases of seed being traded across ethno-linguistic lines. Additionally, poor villagers tend
to trade with poor villagers rather than approaching wealthier members to borrow seed.
In all cases, vegetable seeds are reportedly traded freely without expectation of return in
terms of cash, seed, or produce. Regarding the scope of seed pathways, villagers who are
recently resettled refugees recount how they left China approximately 50 years ago,
carrying seeds of their culturally most defining crops, but that some of these species were
later lost as they fled through conflict in Burma and into Thailand. This community has
rebuilt its current vegetable array of 50 species through various sources: their relatives
residing on the Thai-Burma border, a national agricultural development organization, and
local seed markets.
A diverse list of perennial and annual vegetable crop species for which seed was
donated was created in the first village cluster of Chiang Dao, Thailand. This list
represents 36 unique accessions, 20 unique varieties (of which 23 have been positively
identified, twelve households, and four villages (Table 2). To our knowledge, this is a
seminal baseline list of indigenous vegetable crops cultivated in Northern Thailand.
In addition to the vegetable seed list related to donated seeds, a total of three seed
treatments, seven storage containers, and four storage locations were identified in the first
village cluster (Table 3). It appears that sun drying is the preferred method of preparing
seeds for storage (21 accessions) followed by drying on the plant (13 accessions). Fire
drying was used only for 2 accessions, but these accessions were for the same vegetable
(Bitter eggplant) and were donated by two separate households. Common indigenous
knowledge must lead these two families to prepare seeds of the same plant in the same
way. Plastic bags hung on walls (12 accessions representing 11 varieties and 5
households) followed by plastic bags stored above the fire (8 accessions representing 8
varieties and 5 households) were the most common storage containers and storage
locations among the four villages of Chiang Dao. It is assumed that plastic bags are used
because they are readily available, inexpensive, and can be made water-tight to preserve
seed viability.
A total of 36 accessions were procured from the Chiang Dao village cluster and
subjected to seed viability experiments. All accessions of farmer-saved seeds had a mean
seed viability of 42.5%, and a mean time to 50% germination of 4.9 days. Future work
will try to corroborate the viability of donated seeds (across all three village clusters) to
particular species, varieties, and seed preservation and storage methodologies.
Using ongoing village research through the spring of 2011, baseline data of local
seed systems will be created that will strengthen farmer seed systems. The compilation of
a diverse list of annual and perennial vegetable crops will benefit farmers and researchers
alike, and noteworthy germplasm collected for the ECHO Asia Seed Bank will be
evaluated and distributed free-of-charge to farmers, researchers, and NGO workers across
Asia. Comparisons of farmer seed saving methodologies used on farmer saved seeds to
commercially available seeds will highlight useful appropriate storage and preservation
methods that can be disseminated to other farmers, villages, and areas. In-village research
will empower farmers and community members to begin testing their own seed stocks,
leading to improved seed storage and viability. Most importantly, this research will
strengthen linkages between diverse actors (ECHO Asia Seed Bank, Maejo University,
Pennsylvania State University, and farmers), strengthening indigenous informal seed
systems.
This research outlines a new approach for strengthening indigenous seed systems
in northern Thai and Cambodian communities and potentially extending the reach and
impact of valuable, locally-adapted crop species. The key to success is the adoption of a
holistic approach that empowers resource-poor households and communities, fortifies
indigenous seed pathways, promotes seed system best practices, and preserves and
improves the rich genetic biodiversity of the system. In order to continue strengthening of
informal seed systems within the Southeast Asia region, there is an urgent need to scale
up this research into further communities and countries. This scale-up is critical in
preserving biodiversity, ensuring food security and facilitating the sustainable
development of these rural agroecosystems. For maximum impact, it is hoped that this
methodological approach to strengthening informal seed systems can be extended into
other countries in the Southeast Asia region faced with community food insecurity,
including Bangladesh, Laos, and Vietnam.
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Tables
Table 1. Methodologies, expected results, and expected impacts of this research.
________________________________________________________________________
Methodologies
Expected Results
Expected Impacts
-Village mapping
-Seed species
-Linkages/partnerships
-Village surveys
-Seed pathways
created and strengthened
-Household interviews
-Germplasm gatekeepers
-Local people empowered
-Photo card sorts
-Seed system best practices -Knowledge and seed transfer
-Seed tests
-Seed viability
-Preservation of biodiversity
-Germplasm distribution
-Baseline data of local
through ECHO Asia
vegetable seed systems
Seed Bank
-Extension of seed system
best practices
Table 2. Accessions, Latin binomial, and local names of donated vegetable seeds in
Chiang Dao village cluster.
________________________________________________________________________
Or
Generated accession
Plant name
Common/local name
number
(Latin binomial)
CD-20
Abelmoschus esculentus
CD-31
Abelmoschus esculentus
CD-13
NA1
bitter eggplant
CD-21
NA
bitter eggplant
CD-35
Cajanus cajan
CD-10
Carica papaya
CD-19
Carica papaya
CD-32
Cucumis sativus
CD-17
Cucumis sativus
CD-6
Cucumis sativus
CD-15
Cucurbita moschata
CD-12
Cucurbita moschata
CD-4
Cucurbita moschata
CD-28
NA
daeng lai
CD-5
NA
daeng lai
CD-9
NA
daeng lai
CD-7
NA
dang sak
CD-33
NA
eggplant
CD-36
Lagenaria siceraria
CD-23
NA
long bean var. lai
CD-25
NA
luffa lai
CD-24
Luffa cylindrical
CD-29
NA
nightshade
CD-30
NA
nightshade
CD-3
NA
pak chee
CD-22
NA
pak chee hom
CD-18
NA
pak chee lao
CD-26
NA
pak gahd
CD-27
NA
pak gahd
CD-34
Phaseolus vulgaris
CD-14
Psophocarpus tetragonolobus
CD-2
Vigna umbellate
CD-1
Vigna unguiculata ssp. Sesquipedalis
CD-8
Vigna unguiculata ssp. Sesquipedalis
CD-16
Vigna unguiculata ssp. Sesquipedalis
CD-11
Vigna unguiculata ssp. Sesquipedalis
________________________________________________________________________
1
NA= At this point in time, the proper Latin binomial has yet to be assigned
Table 3. Seed storage method and location as by number of accessions, number of
varieties, and number of households in Chiang Dao village cluster.
________________________________________________________________________
Storage method
Storage location Accessions Varieties Households
(#)
(#)
(#)
Plastic bag
Above the fire
8
8
5
Plastic bag
Hung on wall
12
11
5
Cloth bag
Above the fire
2
2
2
Cloth bag
Hung on wall
3
3
1
Open basket
Outside of kitchen
3
3
1
Plastic screw top jar
In kitchen
3
3
1
Open seed inflorescence
Above the fire
2
1
2
In pod
Hung on wall
2
1
2
Rice bag
In kitchen
1
1
1