Southern Sudan has a low population density, abundant land and tremendous agricultural potential. A large number of domesticated crops are grown in the region in a range of cropping systems. There are also numerous useful wild plant genetic resources. Little collecting work has been done in the region, there are few accessions from southern Sudan stored ex situ and publications on the actual and potential plant genetic resources for agriculture are sparse. The region has been a centre of civil conflict with little respite since independence in 1956. The farmers’ fields and natural environments represent in situ genebanks, which following the cessation of hostilities will become extremely important for the rehabilitation of subsistence agriculture, the promotion of cash crop production and the revitalization of the regional economy. Several wild plant species are highly nutritious and merit the attention of plant scientists. This article describes some of the domesticated, semi-domesticated and wild plant genetic resources of the area, and suggests why these are important for agricultural rehabilitation following implementation of a peace accord.

The Andean region of Ecuador is the place of origin of many maize landraces grouped into 24 races. Definition of priorities for maize diversity conservation in this region can be supported by the spatial identification of areas with a high eco-geographical and phenotypic diversity. Six hundred thirty-six maize samples were morphologically characterized using 14 descriptors and assigned to a distinctive race. Additionally, sampled farms were characterized by 12 environmental variables. From these data, maps of morphological and eco-geographical diversity were obtained by using techniques to determine eco-geographical and phenotypic distances and applying them to each geographical neighbourhood. The races Patillo Ecuatoriano, Racimo de Uva and Uchima exhibited high intra-racial morphological variation, particularly in the shape of the ear, kernel row layout, cob diameter and total kernel number. The highest number of different races was observed in Imbabura, Azuay and Chimborazo provinces. The highest levels of morphological diversity were found in three cells (10 × 10 km), located in Pichincha, Chimborazo and Loja provinces. Two ecological niches, located in Loja province, showed high levels of eco-geographical diversity. A comparison between diversity maps revealed shared hotspots of morphological and eco-geographical diversity in the central and southwest areas of Imbabura province. The Andean highlands of Ecuador are an optimal refuge for the conservation of maize diversity, and the criteria of eco-geographical and morphological diversity and race richness should be considered when defining priority in situ conservation areas.

Underutilized crops tend to harbor high levels of genetic diversity, be maintained on-farm in small-scale farming systems and be relatively neglected by formal research and development strategies, including breeding programs. While high genetic variability allows these crops to adapt to marginal environments, inappropriate management practices and reductions in population sizes in individual farmers’ plots may lead to productivity loss and poor harvests. This situation further limits their cultivation and use, notwithstanding the potential these crops may hold for diversification of agricultural systems, food security and market development. Peru hosts a wealth of native agrobiodiversity, which includes many underutilized crops. To improve their performance and promote their continued conservation and use, a participatory breeding program was developed on five underutilized crops of the Peruvian highlands; the breeding approach, based on a combination of evolutionary and participatory methods, is designed to achieve a balance between yield improvement and maintenance of genetic diversity. Preliminary results in quinoa and amaranth are encouraging, fostering further engagement of farmers by increasing availability of quality seed for downstream uses. However, methodological, financial and institutional issues need to be addressed for the effort to be expanded and upscaled. This paper provides an overall description of the initiative as well as a discussion on early results obtained in quinoa and amaranth, highlighting those aspects that make this approach particularly relevant for minor crops and identifying the opportunities and challenges for the initiative to move forward.

Cocoa-based small-scale agriculture is the most important source of income for most farming families in the region of Alto Beni in the sub-humid foothills of the Andes. Cocoa is grown in cultivation systems of varying ecological complexity. The plantations are highly susceptible to climate change impacts. Local cocoa producers mention heat waves, droughts, floods and plant diseases as the main impacts affecting plants and working conditions, and they associate these impacts with global climate change. From a sustainable regional development point of view, cocoa farms need to become more resilient in order to cope with the climate change related effects that are putting cocoa-based livelihoods at risk. This study assesses agroecosystem resilience under three different cocoa cultivation systems (successional agroforestry, simple agroforestry and common practice monocultures). In a first step, farmers’ perceptions of climate change impacts were assessed and eight indicators of agroecological resilience were derived in a transdisciplinary process (focus groups and workshop) based on farmers’ and scientists’ knowledge. These indicators (soil organic matter, depth of Ah horizon, soil bulk density, tree species diversity, crop varieties diversity, ant species diversity, cocoa yields and infestation of cocoa trees with Moniliophthora perniciosa) were then surveyed on 15 cocoa farms and compared for the three different cultivation systems. Parts of the socio-economic aspects of resilience were covered by evaluating the role of cocoa cooperatives and organic certification in transitioning to more resilient cocoa farms (interviews with 15 cocoa farmers combined with five expert interviews). Agroecosystem resilience was higher under the two agroforestry systems than under common practice monoculture, especially under successional agroforestry. Both agroforestry systems achieved higher cocoa yields than common practice monoculture due to agroforestry farmers’ enhanced knowledge regarding cocoa cultivation. Knowledge sharing was promoted by local organizations facilitating organic certification. These organizations were thus found to enhance the social process of farmers’ integration into cooperatives and their reorientation toward organic principles and diversified agroforestry.

The purpose of this study is to identify key home garden species in order to address basic research questions aimed at understanding farmers' home gardens management practices. The study was conducted in two contrasting Hill and Tarai sites in Nepal with households (HHs) ranging from 355 to 634. Unlike larger production systems, home gardens harbour many species in small areas often with a few crop varieties and species that are not well represented in larger fields. Given the number of species and their small population sizes, species and genetic diversity are best studied by identifying representative key species characterizing the complex productive niches within farms. Although species diversity within community is large (172–342), 24 key species were identified for the study. There is no fixed size of a home garden. The log of home garden size and species richness was positively correlated (r = 0.42, P < 0.001). Species richness was significantly higher in vegetable followed by fodder, fruits and spices. This paper also explores the diversity in home gardens to identify the composition and characteristics of the key species and how they are managed, used and conserved. Most of the farmers save the seeds of these home garden species for their own use, but many also exchange and buy and sell seed in local weekly market. Farmers' practices for selecting seed vary according to the reproductive biology of the key home garden species. Home gardens provide the HH with fresh and diverse supply of nutritious food, which improves their self-sufficiency, while conserving diversity on-farm. Despite this, they are neglected in research and development by policy makers and researchers.

A civil war is being fought in Darfur in western Sudan that has resulted in a humanitarian disaster with large numbers of Sudanese refugees seeking a safe haven in neighbouring Chad. The conflict is largely ecological in origin and is based on competition for natural resources, including plant genetic resources. Western Sudan has relatively low rainfall and supports rainfed sedentary agriculture and nomadic pastoralism, and a range of domesticated plant species is grown under irrigation by seasonal watercourses. Nomadic pastoralist populations move their herds according to established routes of seasonally available range and pasture species. There has always been a delicate balance between the sedentary and nomadic ways of life that through careful use of water and plant genetic resources has maintained the ecology of the region in balance. Drought, deforestation, overpopulation and overgrazing have accelerated desert encroachment and have exerted huge pressures on the ecology of the region. Indigenous plant genetic resources, including many wild species used as famine foods, are the key to livelihoods in the region. The upsurge in violence has resulted in many farmers abandoning their farms and seed stocks. Social systems are disrupted and rehabilitation of agriculture will be very difficult. This article describes domesticated and wild plant genetic resources of southern Darfur and details their importance to livelihoods in the region.