Farmer management of gene flow: The impact of gender and breeding system on genetic diversity and crop improvement in The Gambia

In many tropical countries we can distinguish two seed systems: a formal seed system (comprising breeding companies and national institutes) and an informal seed system, often called farmer seed system (comprising of all farmer activities related to the transfer of seeds). These two systems are intertwined in various degrees for different crops and different regions. Related to these two seed systems are formal and informal crop development systems. In recent years, it is suggested to link these two systems in a more structural way, for example, through Participatory Variety Selection and Participatory Plant Breeding. Various research projects have shown that the integration of these two systems is feasible and provide various advantages compared to formal crop development, such as varieties that better fit farmer' preferences and are better adapted to their conditions, a higher adoption rate of varieties, enhancement of biodiversity and germplasm conservation. It is often suggested that farmer varieties are well adapted to local conditions and that farmers maintain high levels of diversity in their fields, enabling conditions for the creation of new genetic diversity and new varieties. However, how exactly farmers manage such processes, or whether they actually manage these processes at all is not much studied. With better information it will be possible to identify opportunities to maintain and enhance farmer selection practices, and to prevent elimination of local processes of value in maintaining genetic diversity. Hence, the objective of this study was to get a better understanding of local gene flow and its effects on crop genetic diversity (i.e. availability, genetic make-up and diversity of varieties) and as such on the farming system as a whole, and whether these effects are related to or influenced by breeding system, gender, farmer selection, or possibly other agricultural practices, socio-economic factors or cultural understandings, consciously or tacitly.The three main research questions that follow from this objective were:1.     How is gene flow managed by farmers and which factors play a crucial role?2.     What is the impact of gene flow on the adaptability and resilience of the farming system?3.     Based on the answers to questions 1 and 2, what suggestions can be made to integrate formal and informal crop improvement?To answer these questions, the following model of gene flow is used: Gene flow = (seed flow           +         pollen flow)     *         selection pressure To achieve a better understanding how the various factors related to seed flow, pollen flow and selection pressure interact an interdisciplinary approach is used combining natural and social science. A comparative approach is chosen focusing on two key-variables: crop breeding system and gender. In The Gambia millet (an outbreeding crop) is grown by men and rice (an inbreeding crop) grown by women. During the fieldwork, farmer cultivation practices, seed selection and use and management of varieties are compared between millet and rice and between men and women. In the analyses, quantitative and qualitative plant data and socio-economic data are integrated. Chapters 2 to 9 described the various aspects of the model above.In chapter 12, the concluding chapter, these aspects are brought together and the short formula on gene flow (presented in Chapter 1) further elaborated. With this information, and information from Chapters 10 and 11, the second research question is answered. Finally, this information is used to illuminate the third question through some suggestions on how formal and informal crop improvement might be better integrated. Below, a few of the major findings are highlighted.It seems logical that the higher the rate of cross-pollination, the higher the chances are for new varieties to develop in farmers' fields. In Chapter 7, however, it is shown that for pollen flow to result in the development of new genotypes, the level of pollen flow should not be too high. Distinct, stable genotypes develop more easily in crops with a low cross-pollination rate, like rice. Hence, it is also easier for farmers to select off-types in strong inbreeding crops, and develop them into new varieties, than in strongly outbreeding crops. Other factors determining the chances of the development of new stable genotypes are the distances between fields, the time of flowering, the number of varieties in different fields and the number of mixed-in varieties within fields. Farmers do not mind mixed-in varieties in their seed as they consider it insurance. Because of all these factors, chances of cross-pollination between rice varieties are much higher within fields than between fields. Since within a village almost all farmers grow the same variety of millet chances of pollen flow between millet varieties are very low.Although many people (both farmers and scientists) believe that women are better in distinguishing varieties and plant types, Chapter 9 shows there is no difference in capability between men and women. Additionally, both male and female farmers think off-types are caused by God and they do not have a clear understanding of what exactly causes change in rice and millet. Although men and women have a similar understanding on the development of strange off-types in millet and rice, men have never tried to test strange millet off-types, while women sometimes test and develop strange rice off-types into new varieties. As mentioned above, new stable, distinct off-types develop more easily in rice than in millet. Distinctness of off-types is a requirement for farmers to notice them. The harvesting process enables observations of strange off-types in rice more readily than in millet. Additionally, this study found evidence that it is an aspect of male identity not to test any strange off-types. Men often know how to differentiate varieties, but seemingly this is not knowledge that is important to their self image and to their image within the community.The second main research question was whether gene flow plays a role in keeping farming systems adaptable and resilient. In Chapter 10 it was concluded that processes in relation to genetic diversity differ between rice and millet. In the case of rice, pollen flow between varieties and farmer off-type-selection have important roles in the development of new varieties. Moreover, for rice, seed exchange between communities is crucial to maintain genetic diversity at village level and regional level, whereas it is less important for millet. In millet it is primarily pollen flow within varieties and seed selection through which genetic diversity is maintained. It is likely that genetic diversity for rice fluctuates more over time and space than for millet. For rice, the effect of pollen flow and seed flow on genetic diversity shows in the development of new varieties, whereas for millet, seed and pollen flow lead to the maintenance, or in some cases an increase, of genetic diversity at population level.In Chapter 11 it was elaborated that adaptability (and resilience) can be achieved through genetic diversity and plasticity. Chapter 11 elaborated further on the impact of selection on local adaptation. It shows that millet varieties are not narrowly adapted and that variety choice seems more related to cultural preferences than to local adaptation. Although no data are available, it seems that rice varieties are also quite widely adaptable. For rice, another factor that seems to influence variety choice is the time of introduction of varieties in a village and the range of suitable varieties in that village.At farming system level pollen flow likely plays a limited role in keeping populations adaptable to rapid environmental changes. This does not mean that the process of adaptation through genetic evolution at field level should be ignored, but that it is too slow a process, compared to the decision making process of farmers who can decide in a few years (sometimes in only one year) to change varieties.In Chapter 12 the implications of these findings for the importance of gene flow are discussed.Under slowly changing conditions, a high cross-pollination rate contributes to adaptation at field level, which then in turn contributes to adaptation at farming system level. Under fast changing conditions (whether ecological or socio-economic), seed flows (exchange of varieties) are essential to maintain adaptation at farming system level. A low cross-pollination rate also contributes to the adaptability of farming systems through the development of new varieties. Hence, it can be argued that for late millet the process of adaptation is more gradual, while for rice it is more of a stop-and-go process. Whereas late millet populations slowly adapt to the changing climatic conditions in The Gambia, rice varieties tend toward replacement when the 'older' ones do not fit the conditions anymore. Hence,the millet seed system can be considered low-cost and more robust, whereas the rice seed system is more a higher maintenance and less robust system, needing constant exchange and testing of off-types to keep it adaptable.Finally, in Chapter 12 some suggestions are given how to integrate farmer and formal breeding in the context of The Gambia. There is scope to improve the formal breeding system in itself, particularly by improving funding conditions and the capacity of NARI. Important is also to stimulate two-way traffic of information and seed materials between researchers and farmers, and local testing of materials. As farmer breeding is very much a random process, which is also one of its strengths, it is difficult to improve it. There is more scope in improving farmer breeding by linking it to the formal system. One way to link farmer and formal breeding is through PVS methodologies which can be easily integrated into the 'conventional system of crop improvement'. If formal breeding is improved following the above suggestions, PPB methodologies do not have any apparent advantages in the context of The Gambia, but may be used to reflect how conventional breeding methods can be improved. In the last section it is emphasised that as long as formal crop development excludes particular crop types, farmer crop development remains to play an important role, particularly in risk-prone environments. A last remark is that crop development can only improve agriculture as part of a farming systems approach understanding the complex processes through which crops are formed, maintained and improved

Witte lupine voor kalkrijke bodems : onderzoek over twee jaar naar perspectiefvolle lijnen

Lupine (Lupinus spp) kan interessant zijn voor zowel biologische als gangbare akkerbouwers die zoeken naar een vlinderbloemig gewas om hun vruchtwisseling te verruimen, niet alleen als veevoer maar ook voor humane voeding. De beschikbare rassen kunnen echter alleen op kalkarme (zand‐)grond geteeld worden, terwijl de grootste arealen akkerbouw in Nederland op kalkrijke kleigronden liggen. Er is dus behoefte aan kalktolerante rassen

Organizational analysis of the seed sector of rice in Guinea: stakeholders, perception and institutional linkages

This paper analyses the organization of the rice seed sector in Guinea with the overall objectives to assess how organizational settings affect seed supply to small-scale farmers and to suggest institutional changes that would favour seed service and uptake of varieties. Data were collected in Guinea, West Africa, using focus group discussions with extension workers, farmers, representatives of farmers’ associations, agro-input dealers, researchers and non-governmental organization (NGO) staff, and surveys of 91 rice farming households and 41 local seed dealers. Findings suggest that the current institutional settings and perceptions of stakeholders from the formal seed sector inhibit smallholder farmers’ access to seed. Seed interventions in the past two decades have mainly relied on the national extension system, the research institute, NGOs, farmers’ associations and contract seed producers to ensure seed delivery. Although local seed dealers play a central role in providing seed to farmers, governmental organizations operating in a linear model of formal seed sector development have so far ignored their role. We discuss the need to find common ground and alternative models of seed sector development. In particular we suggest the involvement of local seed dealers in seed development activities to better link the formal and the informal seed systems and improve smallholder farmers’ access to seed from the formal sector

Kalktolerante lupinerassen: tweejarige test van lupinelijnen (blauw, wit) op kalkrijke zavelgrond in Zeeland

In 2012 en 2013 zijn veldproeven opgezet waarin lijnen van witte lupine en rassen van blauwe lupine zijn vergeleken. De witte lupine lijnen komen van twee veredelaars uit Nederland en Denemarken, de blauwe lupine rassen komen van zaadbedrijven uit Denemarken, Duitsland en Polen. Deze lijnen en rassen zijn beoordeeld op opbrengst, vroegheid bloei, vroegheid afrijping, aantal etages (aantal bloeiwijzen per plant) symptomen kalkchlorose, bladgezondheid, planthoogte, bodembedekking en legering. In dit kader is het doel van dit project om veredelingslijnen van witte lupine en rassen van blauwe lupine te testen op met name opbrengst, kalktolerantie en kwaliteit in een tweejarige veldproef in 2012 en 2013 op kalkrijke zavelgrond in Zuidwest‐Nederland. De uitkomsten hiervan bieden een waardevol uitgangspunt voor veredelingsbedrijven om een verdere veredelingsinspanning te leveren

Praktijknetwerk: natuurgrond, graan en onkruid : eindrapportage 2012-2014

Uit verschillende media en projecten blijkt dat er een groeiende belangstelling is vanuit zowel consument als verwerker voor regionale producten gemaakt van biologisch graan. In Gelderland werken natuurorganisaties samen voor het lokaal beheren van natuurgronden, om op die manier biodiversiteit te verhogen. Die gronden zijn van belang om graangewassen te kunnen telen, o.a. voor stro en veevoer. Op deze natuurakkers kan graan geteeld worden voor de verkoop als regionaal product, o.a. in de vorm van brood en meel

Nieuwe wegen voor de veredeling van gewassen voor kleine markten : sleutelelementen voor vruchtbare samenwerking in de keten

Voor het veredelingsbedrijfsleven is het nog beperkte biologische areaal een belangrijke bottleneck om te investeren in biologische selectie. Vanuit de biologische sector is er behoefte aan het vinden van innovatieve vormen van financiering of organisatie van veredeling om de vicieuze cirkel te doorbreken. Er zijn een aantal sleutelelementen geïdentificeerd die belangrijk zijn voor het succesvol opzetten van dergelijke initiatieven: erkenning van een probleem binnen de gehele keten, de complexiteit van de keten en haar geschiedenis, planteigenschappen, en ondersteuning voor ontwikkeling van nieuwe vormen van samenwerking. Mogelijke verbeterpunten qua organisatie zijn aanpassing van bestaande veredelingsstrategieën en betere afstemming tussen ketenpartners op Europees niveau. Dit laatste punt kan ook perspectief bieden op het gebied van financiering. Qua communicatie zijn kortere lijnen tussen telers en veredelaars belangrijk

The rice seed sector in Guinea: Are we missing out crucial stakeholders?

The low use of improved rice seed by farmers in west Africa is not well understood. This study assessed how institutional settings and stakeholder perceptions in the formal rice seed sector inhibit small-scale farmers’ access to improved seed. Data were collected in s Guinea, west Africa, in 2007 and 2008. To understand the dynamics of seed interventions in Guinea since the 1980s, key persons were interviewed and relevant literature was reviewed. The results show that, although local seed dealers play a central role in providing seed of local and improved varieties to farmers, seed interventions have mainly relied on the national extension system, NGOs and a new class of contract seed producers that abide by rules and regulations set by the formal seed system. Within a linear model of seed sector development, governmental organizations, the most influential stakeholders of the formal seed system, have been unaware of the central role of local seed dealers in the informal seed system. We argue that in the context of weak extension service due to lack of financial and human resources, farmer-to-farmer dissemination approach centered on the local seed producers and dealers is an option that could be explored to enhance small-scale farmers’ access to improved seed. The local seed producers and dealers have shown their willingness to participate in such seed development activitie

Robustness and Strategies of Adaptation among Farmer Varieties of African Rice (Oryza glaberrima) and Asian Rice (Oryza sativa) across West Africa

This study offers evidence of the robustness of farmer rice varieties (Oryza glaberrima and O. sativa) in West Africa. Our experiments in five West African countries showed that farmer varieties were tolerant of sub-optimal conditions, but employed a range of strategies to cope with stress. Varieties belonging to the species Oryza glaberrima – solely the product of farmer agency – were the most successful in adapting to a range of adverse conditions. Some of the farmer selections from within the indica and japonica subspecies of O. sativa also performed well in a range of conditions, but other farmer selections from within these two subspecies were mainly limited to more specific niches. The results contradict the rather common belief that farmer varieties are only of local value. Farmer varieties should be considered by breeding programmes and used (alongside improved varieties) in dissemination projects for rural food security