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 ofcrop 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 speciesto 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 increasinglyover the past decade arealso 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 non-commercial 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-by-species 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 seed-saving 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 seedbank 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 grow-out 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.