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As the climate continues to change, forestry jurisdictions that have implemented assisted migration are looking to ever-warmer locations to find tree seed sources that are climatically adapted to their reforestation sites. This may result in having to procure seed from neighbouring jurisdictions, with whom seed and seed transfer systems are not typically shared. Using recent literature on institutional response to climate change and taking British Columbia's need for seed from the US Pacific Northwest (PNW) as a case study, we survey stakeholders to examine barriers to interjurisdictional seed movement, and address more broadly the ability of institutions to respond to climate change. We detected no significant institutional or informational barriers to increased seed procurement from the PNW. Nonetheless, risk and change aversion associated with new tools, actors, and practices may constrain implementation efforts. Reduced jurisdictional isolation could create significant opportunities and efficiencies in the seed supply chain and could help locate the best adapted species or seed source for each plantation. Our findings suggest climate change adaptation across multiple actors and geographies is possible. Placing more emphasis on the human elements of the system - the actors, their interests, and incentives - may help improve our capacity to deliver effective climate change adaptation actions. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Large quantities of diverse native seeds are required to scale up global restoration efforts. However, it remains unclear for many ecosystems how the diversity of available seed in commercial stocks reflects the composition of the ecosystems where vegetation is being remade. This study highlights existing shortfalls in the diversity of seed presently available for use in restoration and identifies gaps in the seed supply chain while providing a new method for optimising species selection given these constraints. This work underscores how improved collaboration between stakeholders is required to strengthen the seed supply chain and help remake functionally diverse vegetation. Summary: Restoration using native seed is frequently implemented to restore degraded ecosystems. However, it remains unclear how constraints on the diversity of germplasm available for use in restoration may limit the recovery of both species and plant functional diversity.Using a dataset of seed availability for Australia's major vegetation types, we explore variation in the diversity and breadth of functional traits (leaf mass per area, seed mass, plant height) for species where seed is available on commercial markets relative to unavailable. Using these data, we simulate theoretical seed mixes derived from two species pools: (1) constrained by the current market of commercially available seed, and (2) assuming all native species can be planted; then we compare differences in functional diversity (dispersion) as an exercise to explore possible limitations within the current seed supply.Seed from only 12% of Australian plant species (2992 species) is presently available for immediate purchase. Seed was more frequently available for trees and shrubs than for understorey species. Available species were on average taller, with thicker, longer‐lived leaves than unavailable species. Overall, functional dispersion was lower for seed mixes generated using available seed compared with those drawn from all species.Solutions are required to address seed shortfalls so that plantings are not only species rich but also functionally diverse. We develop two options: (1) quantifying and addressing gaps in the seed supply chain that currently limit the capacity for practitioners to restore diverse vegetation; and (2) applying a trait‐informed species‐selection method to plantings that maximises functional diversity using available seed. [ABSTRACT FROM AUTHOR]

Native plants form the foundation of our environment and are essential for the proper functioning of ecological systems. Therefore, native plant materials (primarily seeds) are in high demand as land managers and ecological restoration practitioners seek to use them in restoration projects. However, the state of the native plant material system that supplies seed for land management and ecological restoration is underdeveloped. The native plant industry is experiencing an exciting period of growth, offering numerous opportunities to enhance our understanding of native plant production and restoration. We briefly discuss how the demand for native plant materials is a relatively recent phenomenon driven by changing land management paradigms and highlight two areas ripe for further development to capitalize on the momentum of the native seed market. [ABSTRACT FROM AUTHOR]

In the case of maize farmers, access to seeds for planting is essential. We describe access to and exchange of maize seed in three sub-regions (central, eastern and western) in the states of Puebla and Tlaxcala, in order to analyze the use of maize seed in a rain-fed plateau region, based on local diversity. In 2013, 86 local maize producers were interviewed, 43 of whom participated in the Custodian program for the National System of Plant Genetic Resources (Sistema Nacional de Recursos Fitogenéticos), and 43 others, who did not participate, but were chosen by non-probabilistic sampling. The 86 farmers maintain 193 lots of seeds, differentiated according to grain color (white, red, blue, yellow, pinto and moradillo) and the Cacahuacintle type. There were significant differences between sub-regions in terms of access, exchange and loss of seed lots. 92.7% of the seed used in the area is native maize derived from self-sufficiency within the community or family (81.9%), with a low replacement rate (79.8%) and when a new batch of seeds is required, this is acquired within the community itself (86.0%); there is limited exchange (55.9%), between family members or close social networks. A community seed supply system prevails, due to being very accessible and people's confidence in the adaptability of the acquired genetic material, promoting in situ conservation of native maize; even though farmers do have access to improved varieties. [ABSTRACT FROM AUTHOR]

To cope with interannual climate variability, many farmers in tropical and sub-tropical regions choose crop varieties that fit seasonal climate conditions. Therefore, seed demand for different varieties, such as early- or late-maturing cultivars, varies between years. Resulting mismatches between relatively constant supply and variable demand create losses for both seed suppliers and farmers. Because demand for seed of different varieties is influenced by seasonal climate, however, probabilistic seasonal rainfall forecasts could help seed suppliers better anticipate upcoming seed demand. To explore this idea, we engaged decision-makers from seed supply organizations in Zimbabwe and Ethiopia. Through a participatory design process, we identified opportunities and challenges for using seasonal rainfall forecasts to inform seed supply decisions. In a case study of maize seed sales in Zimbabwe, we tested our assumptions and iteratively devised a systematic procedure for forecast-based planning in seed supply, relying on free online data sources and expert deliberations. We found that currently accessible rainfall forecasts could indeed be useful for prioritizing likely high-demand varieties during the stages of seed treatment, packaging, and logistics. In practice, though, more flexible and adaptive management of seed supply pipelines might be required to make use of seed demand forecasts. In the future, targeting farmers with climate forecasts along with recommended variety portfolios may strengthen the association between seasonal climate and farmers’ variety demand, increasing the accuracy of demand anticipation. This study highlights opportunities for increased case-specific collaboration between climate scientists and the seed sector to make seasonal forecast information operational.

In Australia grassy communities (in this paper meaning grasslands and grassy woodlands) were extensive in their range prior to European settlement but have since been reduced to a small fraction of that distribution and quality. This is due largely to the impacts of agricultural clearing and urban development. Despite clear knowledge of their threatened state, and discussion of the need for their repair government support for grassy community restoration is poor and programs instead focus largely on simplistic plantings of tree and shrubs. Never-the-less there have been various groups who have continued with tenacity to pursue the goal of grassy community restoration and met with considerable success – albeit at small scale. Importantly, these outcomes have been build on key areas of innovation and knowedge development, helping to overcome barriers which previously led many to consider grassy community restoration unfeasible under Australian conditions. These sucesses invite the possibility that grasslands and grassy woodlands can over time be returned at-scale as integral parts of Australia’s highly modified agricultural, urban, and peri-urban landscapes – where now little still reside.

Almost 1 billion hectares of land have been pledged for restoration globally under the UN Decade on Ecosystem Restoration. Seed‐based restoration will be essential to achieve native revegetation targets in a timely and effective manner. However, problematic seed germination, seeding environments, and seed handling can limit our ability to use native seeds in revegetation. Seed enhancement technologies (SETs) are post‐harvest seed treatments, which may improve seed performance and handling, thereby optimizing seed‐use efficiency and success in restoration. We highlight SETs as a restoration tool accessible to anyone and which can also be used to deliver seed‐based restoration at scale. If SETs are to rise to the challenge of restoration targets in the coming decade, improving native seed supply, research efforts, knowledge and data sharing, and collaboration and funding will be essential. These actions are discussed within a roadmap for advancing SETs in the UN Decade on Ecosystem Restoration. [ABSTRACT FROM AUTHOR]

With the United Nations Decade on Ecosystem Restoration, restoration of damaged ecosystems is turning into a global movement. Restoration actions that are not based on science and an understanding of ecosystem function can thwart desired restoration outcomes at best and cause further damage to ecosystems at worst. Restoration often includes revegetation using seed. Where we source seed for restoration can make a difference for species establishment, restoration outcomes, and recovery of ecosystem function. However, sourcing seeds of native species, let alone genetically appropriate seed, is not currently possible for many restoration projects. The process of increasing and sourcing suitable seed for restoration includes many steps that need to be addressed typically years before a restoration project is initiated. These steps of seed collection, evaluation and development, field establishment, production, certification and procurement, storage, and finally restoration, need to be considered ideally at a scale larger than individual restoration projects and with research conducted in each step. We describe these steps as implemented in the United States, the challenges therein, and provide suggestions and examples of how groups can make efficient and effective progress toward getting the right seed in the right place at the right time. [ABSTRACT FROM AUTHOR]

The Australian native seed sector is critical for undertaking ecological restoration but faces serious challenges from interacting factors, including native vegetation loss and habitat fragmentation, low funding levels, and climate change impacts. The Australian Native Seed Survey was conducted in 2016–2017 to better understand sector structure, practitioner perceptions, and practice. It found that most native seed is collected from small and fragmented tenures and from geographic ranges that greatly exceed "local provenance"; that the diversity of species available for restoration is typically low; that native seed is seldom quality tested; and that most annual seed collections (wild or production) are small in volume suggesting overall seed yields are modest in quantity and not sufficient to support large‐scale restoration. Together, survey findings raise serious concerns about the ability of the sector, as currently constituted and resourced, to meet projected future increases in the demand for seed or for achieving the effectiveness and efficiency required to meet UN‐Decade type ecological restoration outcomes. Central to recommendations for sector improvement are the following focus areas: maturing the native seed sector; sustainability; seed production; licensing; seed testing and tracking; and research. [ABSTRACT FROM AUTHOR]

The Australian Native Seed Sector survey was conducted in 2016–2017 under the auspices of the Australian Network for Plant Conservation. Respondents self‐selected into a seed supply (Seed Collector, Seed Production Area Grower) or seed demand (Seed Purchaser, Other User) group category. Issue statements facing the sector with respect to limiting opportunities for ecological restoration were presented to survey respondents who ranked them in order of importance. Findings revealed that the order of statement importance varied depending on the primary role (Group) of the respondent in the sector. When combined across groups, the issues of most importance were: future seed demand will be difficult to meet from wild harvest; the seed market is unwilling to pay for the true cost of seed collection/seed production; there is a lack of available seed from a broad range of species; and demand for seed is inconsistent and/or unpredictable. The survey also revealed that the native seed sector is underpinned by a remarkably small and underresourced workforce, composed primarily of sole or small operators, which presents a clear concern to all users of native seed, not only in terms of current capacity for ecological restoration, but also to meet any large and rapid increases in future demand. [ABSTRACT FROM AUTHOR]

The main shortcomings in the work of seed treaters were identified, which include increased crushing of seeds, uneven supply, increased humidity of seeds after dressing. It has been established that when the seed treaters are working at seed deliveries of 70-100% of the maximum, there is a sharp change in the quality indicators, which can be reduced by using a two-disk distributing and two-level reflecting devices. The objective of the research is to substantiate the design and technological parameters of a chamber seed treater with a two-disk distributing and two-level reflecting devices that can improve the quality of seed treatment. For this purpose, a prototype chamber seed treater with a two-disk distributing and two-level reflecting devices was developed, manufactured and tested in the field. A study of the sowing qualities and technological properties of seeds of spring wheat of the Raduga variety showed that the seed purity was 99.54%, their moisture content before pickling was 13.9%, their germination rate was 98% with 1000 seeds weighing 41 g, and the crushing of the seeds was 0.14%. The optimal values of the distance between the annular disk and the upper level reflector L1 = 60 mm, the diameter of the lower level reflector D2 = 350 mm, the height of the upper level reflector H1 = 30 mm, the height of the lower level reflector H2 = 30 mm with 0.11-0.05% crushing seeds with the chamber seed treater. The maximum seed flow rate of 5.98 kg/s was established, corresponding to a 2.2% feed irregularity and 0.06% crushing by the chamber seed treater with 150 mm opening of the flap of the petal dispenser.

The government-led system for seed production and distribution of major crops was developed by enforcement of the Major Crops Seed Law in 1962. The Korea Variety and Seed Service has played a key role in operating the system, in cooperation with breeding institutes under the Rural Development Administration and provincial Basic Seed Centers. In the case of rice, the most important crop in the country, the quality of certified seed has continuously improved from the simply cleaned seed in the 1960s to graded, disinfected, coated seed of the present. Its coverage of the total planted area increased from 14% in 1985 to 60% in 2015. Since its inception in 2010, the Foundation of Agricultural Technology Commercialization and Transfer has been involved in the production/distribution of certified seed of minor crops/varieties, which had not been properly cared for by the mainstream system previously mentioned. Vegetable seed has been produced and marketed by the private sector. In the latter half of 1950s, seed self-sufficiency was attained in major vegetables. Vegetable seed market became totally open by 1991, and since then Korean seed companies have explored overseas production sites to meet the needs of local and export markets. The acquisition of major local seed companies by multinational major companies in the late 1990s has led to opportunities for Korean vegetable seed firms to upgrade their operational plant production and quality assurance practices to global standards. The quality of vegetable seed offered by Korean companies today is at the top level in the world market. The small and ever-decreasing size of the local seed market has been and will be a serious factor limiting the seed business in Korea. It is necessary to develop technologies to overcome the meteorological disasters that are becoming more violent and more frequent due to climate change. Labor-saving technologies are in urgent need in the area of field production. Phytosanitary border control systems need to evolve to more science-based reasonable ones. Seed enhancement technology, such as biological treatment, is becoming an essential part of holistic farm solutions, where seed is not only a carrier of the genetic constitution of a plant variety, but also plays a complementary role in making up for limitations of varieties and/or cultural managements practices. It is necessary to be adaptive and incorporate new sciences and technologies such as artificial intelligence, new breeding technologies, and epigenetics, among others. [ABSTRACT FROM AUTHOR]

We argue that the need for a quality seed supply chain is a major bottleneck for the restoration of Chile's native ecosystems, thus supplementing the list of bottlenecks proposed by Bannister et al. in 2018. Specifically, there is a need for defining seed transfer zones, developing standards and capacities for properly collecting and storing seeds, reducing information gaps on seed physiology and longevity, and implementing an efficient seed supply chain with certification of seed origin and quality. Without such capacities, countries are unlikely to meet their restoration commitments. Although we focus on bottlenecks in Chile, the issues we raise are relevant to other countries and thus the global agenda for ecological restoration. [ABSTRACT FROM AUTHOR]

• Proper seed source selection is key for tropical forest restoration/reforestation. • Piecewise structural equation models assessed phenotypic effects on seedling quality. • Scarification, not tree phenotype, drives germination success in Coulteria platyloba. • Provenance, rather than tree phenotype, affects seedling quality in C. platyloba. • Both natural and managed populations should be used as seed sources for this species. A major obstacle faced by reforestation/restoration programs is an insufficient supply of high-quality seed. Seed collection is commonly based on opportunistic strategies that only consider availability and distance to seed sources, but not seed quality. Although for commercial timber species from temperate ecosystems the selection of individuals with above-average phenotypes often results in high-quality seeds and seedlings, the validity of this criterion has not been assessed in tropical dry forests (TDF). By using the abundant TDF tree Coulteria platyloba as study model and piecewise structural equation modelling (pSEM), we examined the associations between germination success and seedling growth, and various tree, fruit and seed characteristics, for seeds from two provenances (natural vs. managed populations), that were either scarified or not. Unexpectedly, phenotypic attributes of trees, fruits and seeds had no effect on germination success, as this response variable depended on scarification only. Also, fruit quality was unrelated to tree size, but it was related to provenance. According to pSEM, the best supported path resulting in high quality seedlings established a relationship between managed populations, high quality fruits and seedlings with better roots systems, but only for seeds that were scarified and did not germinate very rapidly. Overall, the assessed relationships were complex, weak, and sometimes difficult to interpret. Nonetheless, these results provide guidance to improve seed source selection efforts that consider operation costs of nurseries and the success of future plantations. In TDF, selecting trees with above-average phenotypes as seed sources does not necessarily favour the quality of seedlings used to restore degraded areas. In these ecosystems, we recommend a seed collection strategy that combines managed and natural populations as seed sources to maximize genetic variability in future plantations, while improving nursery operation efficacy. [ABSTRACT FROM AUTHOR]

Genebanks explore new partnerships with farmers and other user groups to provide smallholder farmers in Africa better access to crop diversity for improved nutrition, climate change adaptation and agricultural diversification. This paper shows how the World Vegetable Center (WorldVeg) genebank of traditional African vegetables and its partners distributed over 42,000 seed kits containing over 183,000 vegetable seed samples from 2013 to 2017 to smallholder farmers in Tanzania, Kenya and Uganda. The seed kits contained seed samples of promising accessions and open-pollinated breeding lines of traditional African vegetables, and to a lower degree of tomato, Capsicum pepper and soybean, usually enough to plant in a home garden. We identified four research questions to better understand the role of vegetable seed kits in strengthening local seed systems, impact on local vegetable diversity, improving human nutrition and supporting climate-resilient agriculture. As formal seed systems expand their reach, the genebank's role to supply vegetable diversity to public and private breeding programmes becomes more important. To optimize supply of vegetable diversity, the WorldVeg genebank of traditional African vegetables continues working with partners in both formal and local seed systems. [ABSTRACT FROM AUTHOR]

Oyster culture activity along the eastern Amazon mangrove coast in Pará state, Brazil, was evaluated using socio‐economic data to support its management and future development. Between 2013 and 2014, surveys were carried out in the region's seven oyster culture associations through interviews with the president of each association as well as with 56 members (72% of the total). Further data up to 2016 were obtained from annual reports of the Serviço Brasileiro de Apoio às Micro e Pequenas Empresas in Pará and the Instituto Brasileiro de Geografia e Estatística. Two associations stand out from the rest due to their larger on‐growing areas and total production in 2013. However, smaller associations are more efficient with higher production per unit area. Currently, oyster culture in Pará provides an alternative source of income for 80 families, where total production has increased from 8.25 tons in 2013 to 41.8 tons in 2016. Although associations have grown in number since 2006, along with increased capacity and production due to government assistance, in comparison with other regions of Brazil, they need to be better organized internally, including regular monitoring of growth, production and environmental variables, development of depuration facilities and improved distribution and presentation of products. Diversification of seed supply among different locations is desirable. There should also be less dependence on public funding and more partnerships with private enterprise, as well as active coparticipation in the development of legislation and public policies regulating both oyster culture and protection of natural oyster beds. [ABSTRACT FROM AUTHOR]

Highlights • Low levels of seedling recruitment were found in shelterwood-treated jarrah forest. • Recruitment was strongly linked to levels of canopy seed store and seed fall. • A minor positive effect of ashbed, particularly areas burnt to mineral soil, was found. • Adequate seedling recruitment following logging in jarrah forest may require more intense fire. Abstract Successful and adequate recruitment of seedlings is an essential ecological process in forest ecosystem dynamics and is a key principle underpinning sustainable timber harvesting. This is particularly so with the shelterwood silvicultural system used in the jarrah (Eucalyptus marginata) forest of south-west Australia where partial cuts of overstorey are made followed by prescribed burning to stimulate seed fall and seedling establishment. There have been concerns over the lack of seedling recruitment in some shelterwood-treated areas of the jarrah forest, and hence this study was implemented to explore the roles of seed supply and seedbed conditions in limiting recruitment of jarrah seedlings. Low seedling densities were recorded across all six burnt study sites and were strongly correlated (at both broad and fine scales) with both canopy seed store and seed fall. Ample levels of post-burn seed fall only resulted in low seedling numbers suggesting that adequate seed supply did not coincide with seedbed conditions suitable for mass seedling regeneration. Conditions favourable for seedling recruitment were highly variable within sites, since both seed supply and seedbed conditions were spatially heterogeneous. Fine-scale areas burnt to mineral soil showed an additive influence to the overwhelmingly dominant factor of seed supply on seedling recruitment. However, the capacity of low intensity burns to produce these seedbed conditions at a broad scale appears to be limited. Results suggest that successful stocking of shelterwood-treated jarrah forest is not always feasible following a single silvicultural event, such as post-harvest burning under mild conditions. The chances of ample seed supply coinciding with broad-scale seedbed conditions favourable for mass germination, emergence and establishment appear to be low. Successful stocking of shelterwood-treated jarrah forest is more likely to be a longer term outcome achieved through episodic recruitment, especially when favourable environmental conditions coincide with optimal seedbed conditions. Such episodic recruitment strategies may be common in resource-limited systems such as jarrah forest and other dry eucalypt forest systems, where conditions controlling the regeneration niche are often variable and unpredictable. [ABSTRACT FROM AUTHOR]

Countries in South-east Asia are significant producers of aquacultured products and production is increasing. Seedstock for mariculture are provided from both wild capture (‘capture-based aquaculture’) and hatchery rearing (‘full-cycle aquaculture’). Collection of Palinurid lobster pueruli and juveniles is currently the sole source of seedstock for aquaculture. Other mariculture commodities, such as milkfish ( Chanos chanos ) and groupers (Family Serranidae, Sub-family Epinephelinae) are supported by a combination of wild-caught and hatchery-reared seedstock. Mariculture in South-east Asia is typified by low levels of vertical integration, and a high proportion of ‘small-scale’ hatcheries. In Indonesia, small-scale hatcheries are clustered in two main areas: Buleleng Regency in northern Bali and Situbondo in East Java, with small-scale hatcheries comprising 95% and 88% of hatcheries in each area respectively. Fingerling production from these hatcheries is considerable, with 7.3 million grouper and 2.5 billion milkfish fingerlings exported from Bali in 2016. Although several studies have quantitatively evaluated the benefits of small-scale hatcheries to local communities, scant attention has been paid to their regional impact. As an example, much of the global production of around 1 million tonnes per annum of milkfish is supported by fingerling production by small-scale hatcheries in Bali. Despite this acknowledged success, disease remains an ongoing problem for small-scale hatcheries with operators of grouper hatcheries in Bali categorising mortality and financial losses as ‘medium’ to ‘high’. A survey of small-scale hatcheries showed that biosecurity is poor and fish health management approaches are based on previous experience. Factors impacting these approaches include purchaser focus on price at the expense of quality, and limited numbers of hatchery staff with any formal aquaculture training. The impact of disease outbreaks remains a weakness for small-scale hatcheries, and consequently a weakness for the mariculture industries dependent on these as a seedstock source. [ABSTRACT FROM AUTHOR]

The long distance transport of Fe and Zn in the phloem sap of wheat (Triticum aestivum L.) is the key route for seed supply, due to wheat having a xylem discontinuity. To date, our knowledge is limited on Fe and Zn homeostasis in the phloem sap during the reproductive and grain filling stages. With the use of aphid stylectomy to collect samples of phloem sap, we explored maturity and morning versus afternoon (within-day) changes in nutrient and metabolite profiles. Phloem exudate was collected from a wheat breeding line, SAMNYT16, at three times during the grain filling period and at both midday and mid-afternoon. There were significant changes in the concentration of Mg, K, Fe and Zn during the course of grain loading and there were also significant within-day differences for Fe and K concentrations in the phloem exudate during the early phases of grain development. We found that, for K and Fe, there was an increase of 1.1- and 1.4-fold, respectively, for samples taken prior to midday to those from mid-afternoon. There was also a significant decrease in K, Fe and Zn phloem sap concentration of 1.5-, 1.4- and 1.1-fold, respectively, from the start of peak grain loading to the end of grain loading. Of the 79 metabolites detected within samples of phloem exudate, 43 had significant maturity differences and 38 had significant within-day variability. Glutamine was found to increase by 3.3-5.9-fold from midday to mid-afternoon and citric acid was found to decrease by 1.6-fold from the start of grain loading to the end of grain loading. These two metabolites are of interest as they can complex metal ions and may play a role in long distance transport of metal ions. The work presented here gives further insight into the complex composition of the phloem sap and variability that can occur during the day and also with increasing maturity. [ABSTRACT FROM AUTHOR]

Improved maize seed is instrumental to deliver an Asian-style 'green revolution' for Africa. The paper reviews and makes a comparative analysis of the maize (corn) seed sector and its evolution in Kenya, Tanzania, Uganda and Ethiopia drawing from seed sector surveys and secondary data. Enhancing farmers' access to and use of new maize varieties still presents a number of challenges in eastern Africa - not least due to a number of policy and institutional impediments to the development of the seed sector. The regional seed sectors also show some remarkable contrasts: they have evolved at different speeds and in different directions, driven by diverging agricultural growth opportunities and varying degrees of regulation, liberalization and restructuring. The paper reiterates calls for an enabling environment for private seed companies to evolve in order to serve the diverse farmer communities so that they benefit from existing and future improved maize seed opportunities. [ABSTRACT FROM AUTHOR]

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The seed ecology and regeneration management of birch species in Fennoscandia has been quite thoroughly investigated through decades of forestry research. Nonetheless, there are few methods for precise predictions of spontaneous natural regeneration. In this study a first framework of a model is presented that combines possible seed supply with seed emergence and seedling survival based on GIS data and the results of past experiments. The birch seed supply was calculated by combining spatial data on standing birch volume with birch seed dispersal distributions. The establishment on a site was further estimated based on the effect parameters of soil moisture conditions and soil scarification. This model shows a reduced variance compared to general means of seed supply and partly explains the variation between sites with the same soil scarification treatments. Even though additional management and ecological variables should be incorporated to increase the model’s predictive ability, it could already be of use in practical forestry. [ABSTRACT FROM AUTHOR]

The role of seed producer cooperatives (SPCs) in the Ethiopian seed sector and their contribution to seed supply improvement have received attention from researchers, policymakers, and development partners. However, limited work has been done in reviewing and documenting their involvement in the seed sector development. In this paper, we review and discuss the SPCs in the Ethiopian seed sector. Specifically, we reflect on the contribution of SPCs to improving seed availability and access in the country. The current liberal market system of Ethiopia creates new opportunities for growth as successful enterprises, but also brings new challenges, such as more intense competition for smallholder producers. The government policy encourages SPCs to engage in seed business. We draw on scientific literature, reports, white papers, project documents, and websites. The review reveals that the seed sector in Ethiopia consists of three seed systems: formal, informal, and intermediary seed systems. Each seed system has a specific contribution to the delivery of seed to farmers, but they vary in their approach and respective strategies. The SPCs are categorized in the intermediary seed system because they have features of both formal and informal seed systems. They play a key role in meeting seed demand and contribute greatly to seed supply improvement through high-volume production of seed, crop, and variety diversification, and seed delivery to farmers. They produce and market the seed through various market channels, including direct sales to farmers, sales through contractual agreement, and sales directly to institutional buyers. Their contribution to improving the seed supply and seed security has received considerable recognition by policymakers and development practitioners. Therefore, government and development partners should support and strengthen SPCs to maximize their success in the seed business and their contribution to improving the seed supply in Ethiopia. [ABSTRACT FROM PUBLISHER]

Questions Old-fields and their succession often played crucial role in dynamics of species-rich semi-natural grasslands. Our objective was to assess whether colonization of old-fields by grassland species is limited by the availability of seeds, dispersal abilities, habitat requirements of the species or biotic interactions. In particular, we asked following questions: (1) What are the main constrains limiting frequency of grassland species in old-fields? (2) Is frequency in source habitat (grasslands) and target habitat (old-fields) limited by the same factors/processes? And (3) how the results and their interpretation change after considering species phylogeny? Location Old-fields and grasslands in northern Bohemia, Czech Republic, Europe. Methods Frequency in old-fields and grasslands of 29 plant species was related to a set of species characteristics representing source, dispersal, abiotic and biotic limitation using phylogenetic regression. Results Species frequency in old-fields was significantly correlated with frequency in grasslands. In general, habitat (biotic and abiotic) limitation was more important for frequency in both habitat types without phylogenetic correction. Specifically, frequency in both habitat types was mostly limited by soil preference and in grasslands also by niche width. Old-fields were relatively more colonized by species with better competitiveness. Phylogenetic signal was not detected during phylogenetic regression. Conclusions To preserve high diversity in grasslands, the effort should be directed towards maintenance of soil quality (minimize the use of fertilizers, pesticides and heavy machinery). Colonization of old-fields could be enhanced by reduction of competitive species by introduction of traditional management (e.g., mowing or grazing). [ABSTRACT FROM AUTHOR]

The paper presents smallholder farmers' perceptions on attributes of bread wheat varieties based on primary data collected from 524 households in four major wheat growing areas of Ethiopia. The results indicated high value of attainment indices for improved varieties compared to landraces, which shows how the demanded attributes are embodied more in improved ones. Grain yield and yellow and stem rust resistance are attributes that are desired most compared to others. However, there is high variability in attainment indices among improved varieties for the different attributes, which suggests the need to target varieties for the different environments including disease and drought tolerance. The results also showed inconsistency between the value of attainment indices of varieties and the amount of seed supplied by the formal sector, which resulted in mismatch between demand and supply leading to considerable carryover seed. The formal sector needs to consider diversifying its bread wheat varietal portfolio and increase its capacity for seed supply to respond to emerging challenges and effectively address farmers' preferences. [ABSTRACT FROM AUTHOR]

In recent years, numerous articles have addressed management strategies aimed at assisting forests to adapt to climate change. However, these seldom take into account the practical and economic implications of implementing these strategies, notably, supply of forest plants and seed. Using semi-structured interviews with practitioners involved in the plant and seed supply chain in Great Britain, we highlight a series of practical and economic bottlenecks commonly encountered in the supply of locally sourced seed and domestically produced planting stock for native woodland and hedging markets. We find that adoption of alternative seed sourcing strategies, designed specifically to account for directional climate warming, is likely to exacerbate existing problems by adding further complexity to decisions nurseries make about tree species and seed origins to produce. The lack of long-term market predictability brought about by the current configuration of forestry grants and regulations and, in particular, the administrative systems for processing grant applications is identified as a major impediment to having a sustainable and competitive supply of home-grown and currently adapted planting stock. Finally, the time and effort it takes to supply healthy plants for native woodland creation projects deserves much wider recognition throughout the industry and will be crucial if planting objectives are to be met sustainably. [ABSTRACT FROM AUTHOR]

Soil seedbanks play a key role in the post-fire recruitment of many plant species. Seedbank diversity can be influenced by spatial variability (e.g. geographic location), environmental variability (e.g. soils) and temporal disturbance heterogeneity (e.g. time since fire, TSF) across the landscape. Unlike for aboveground vegetation, relationships between these factors and soil seedbank diversity remain largely unknown. Partitioning the influence of spatial and environmental variability from that of TSF, and explaining how these factors interact with seedbank diversity, will assist conservation managers in their application of prescribed burning. We germinated soil seedbank samples from sites ranging from 1 to 75 years since fire in a heathy-woodland ecosystem across the Otway Ranges in Victoria, Australia. We also measured spatial and environmental variability across sites to partition the influence of these variables and TSF on propagules available for recruitment. We found weak positive relationships between seedbank richness and TSF; however, these relationships varied across the landscape. We found composition did not change considerably over time, suggesting, in this ecosystem, pre-fire age is not strongly influencing propagules available for recruitment post-fire. Our results suggest that spatial and environmental variability influence seedbank composition more than TSF. [ABSTRACT FROM AUTHOR]

This study conducted a social survey on 300 representatives of Nepali farming households to demonstrate robustness of a structural modelling approach for examining and explaining complex land allocation decision problems of managers. It tested the approach specifically for investigating drivers and barriers of farmers’ decisions for allocating lowland under three kinds (hybrid, conventionally improved and local) of rice varieties. The study required working on both irrelevant choice and disutility choice decision problems besides land allocation problems of all individual varieties. It formulated the research problems on a multiportfolios allocation framework and the empirical model in the structural equations modelling setup. The model was estimated in Full Information Maximum Likelihood (FIML) method. The findings of the model were compared with the results of the standard Tobit model (a conventional method). The estimates of the FIML are found better than the Tobit in terms of satisfying the assumptions of the allocation model, properties of standard errors and theoretical expectations of the variables under investigation. The improvements in the estimates make a noticeable change in prediction impacts and policy weightages of the explanatory factors which potentially alter the policy priorities of decision makers. The study identified many interesting factors determining the farmers’ decisions of allocating lowland between the varieties, and resulting discriminatory benefit distribution between social groups. The study with the comprehensive information provides policy makers an avenue to compare and understand managers’ decision problems of allocating lands in politically preferred and not preferred uses, and contributes in making effective policy decisions. This study discussed on the roles of crop research and community support policies and practices for emerging new problems of seed supply and exacerbating social exclusion in the farming communities​. Some policy solutions are also discussed in line with the findings of the study. [ABSTRACT FROM AUTHOR]

Seed is fundamental to broadscale plant restoration when the goal is to re-establish species and ecosystems. But climate change is expected to significantly influence plant reproduction, affecting seed availability and viability as well as planting opportunities. Meeting growing restoration targets within these constraints in new and unfamiliar climates will be challenging. Consequently, we need to develop a range of flexible strategies to ensure that sufficient volumes of viable seed are available to take advantage of planting opportunities under novel environmental scenarios. This requires coordinated leadership to align funding and planting timelines, using seed production areas to improve seed supply, building and maintaining infrastructure to stockpile seed, encouraging research to overcome storage and germination constraints, and developing and implementing new technologies in all of these areas. Increased tolerance to risk and failure will also be required as the application of current restoration practices may not be appropriate as the climate changes. [ABSTRACT FROM AUTHOR]

Seed supply often limits the size and scope of restoration projects that require active revegetation. To meet demand from more and larger tallgrass prairie restoration projects in the Great Plains, U.S.A., seed is wild-harvested-collected from remnant habitats-using agricultural combine harvesters. We investigated the potential impacts of wild-harvest by comparing prairie remnants of northwestern Minnesota that varied in their histories of harvest frequency but were otherwise similar. We asked: (1) Do wild-harvested prairies differ in species composition from unharvested prairies? (2) If so, can life history traits be used to predict the response of prairie communities to wild-harvest? We conducted a retrospective study of 17 prairies harvested for seed frequently (annually/biennially), infrequently (2-3 times), or not at all. We sampled vegetation at 45 points within each site, recording all species present within 0.25 m2 quadrats. To address the first question, we used non-metric multidimensional scaling and Mantel tests, followed by analysis of variance contrasts to identify any species less likely to occur on frequently harvested sites ('harvest-negative'). For the second question, we used logistic regression to test whether lifespan, clonality, and seed production predicted harvest-negative species. Plant community composition in frequently harvested prairies differed from that of infrequently or unharvested prairies. Fourteen species, generally short-lived and non-clonal, were classified as harvest-negative. Our results suggest that frequent wild-harvest disrupts reproduction of species relying on seed, and that life history traits may provide a basis for predicting a species' response to wild-harvest. [ABSTRACT FROM AUTHOR]

The importance of seed provisioning in food security and nutrition, agricultural development and rural livelihoods, and agrobiodiversity and germplasm conservation is well accepted by policy makers, practitioners and researchers. The role of farmer seed networks is less well understood and yet is central to debates on current issues ranging from seed sovereignty and rights for farmers to GMOs and the conservation of crop germplasm. In this paper we identify four common misconceptions regarding the nature and importance of farmer seed networks today. (1) Farmer seed networks are inefficient for seed dissemination. (2) Farmer seed networks are closed, conservative systems. (3) Farmer seed networks provide ready, egalitarian access to seed. (4) Farmer seed networks are destined to weaken and disappear. We challenge these misconceptions by drawing upon recent research findings and the authors’ collective field experience in studying farmer seed systems in Africa, Europe, Latin America and Oceania. Priorities for future research are suggested that would advance our understanding of seed networks and better inform agricultural and food policy. [ABSTRACT FROM AUTHOR]

Vegetation clearing and land-use change have depleted many natural plant communities to the point where restoration is required. A major impediment to the success of rebuilding complex vegetation communities is having regular access to sufficient quantities of high-quality seed. Seed-production areas (SPAs) can help generate this seed, but these must be underpinned by a broad genetic base to maximise the evolutionary potential of restored populations. However, genetic bottlenecks can occur at the collection, establishment and production stages in SPAs, requiring genetic evaluation. This is especially relevant for species that may take many years before a return on SPA investment is realised. Two recently established yellow box (Eucalyptus melliodora A.Cunn. ex Schauer, Myrtaceae) SPAs were evaluated to determine whether genetic bottlenecks had occurred between seed collection and SPA establishment. No evidence was found to suggest that a significant loss of genetic diversity had occurred at this stage, although there was a significant difference in diversity between the two SPAs. Complex population genetic structure was also observed in the seed used to source the SPAs, with up to eight groups identified. Plant survival in the SPAs was influenced by seed collection location but not by SPA location and was not associated with genetic diversity. There were also no associations between genetic diversity and plant growth. These data highlighted the importance of chance events when establishing SPAs and indicated that the two yellow box SPAs are likely to provide genetically diverse seed sources for future restoration projects, especially by pooling seed from both SPAs. Seed production areas (SPAs) are one way to ensure the regular supply of high genetic quality seed for restoration. This evaluation of two Yellow Box SPAs found that genetic diversity is similar to that of natural populations. These SPAs will provide high quality seed for future restoration projects and reduce the need to collect from wild populations. [ABSTRACT FROM AUTHOR]

Limited empirical evidence exists on how multiple binding constraints influence the adoption of improved technologies by smallholder farmers. This article uses the case of groundnut variety adoption in Uganda to investigate the role of information, seed supply, and credit constraints in conditioning technology uptake. New data from a household survey in seven groundnut growing districts ( n = 945) indicate that 8% of farmers lack information on new varieties, while 18% and 6% of farmers, respectively, cannot adopt mainly due to seed supply and capital constraints. A tobit-type specification that considers all nonadopters as being uninterested in the technology (i.e., corner solutions) would lead to inconsistent parameter estimates and incorrect conclusions in this context. We therefore estimate a modified multi-hurdle specification of demand for new varieties, taking into account how information, seed supply, and capital constraints jointly determine adoption probability and intensity. The study reveals new empirical insights on why agricultural technology adoption in Africa has lagged behind: slow uptake is not mainly due to a lack of economic incentives, but rather a reflection of information, seed supply, and credit constraints that prevent farmers from translating their desired demand into adoption of modern varieties. Policy implications are discussed. [ABSTRACT FROM AUTHOR]

* Premise of the study: Salt marshes are highly productive and valuable ecosystems, providing many services on which people depend. Spartina alterniflora Loisel (Poaceae) is a foundation species that builds and maintains salt marshes. Despite this species' importance, much of its basic reproductive biology is not well understood, including flowering phenology, seed production, and the effects of flowering on growth and biomass allocation. We sought to better understand these life history traits and use that knowledge to consider how this species may be affected by climate change. * Methods: We examined temporal and spatial patterns in flowering and seed production in S. alterniflora at a latitudinal scale (along the U.S. Atlantic coast), regional scale (within New England), and local scale (among subhabitats within marshes) and determined the impact of flowering on growth allocation using field and greenhouse studies. * Key results: Flowering stem density did not vary along a latitudinal gradient, while at the local scale plants in the less submerged panne subhabitats produced fewer flowers and seeds than those in more frequently submerged subhabitats. We also found that a shift in biomass allocation from above to belowground was temporally related to flowering phenology. * Conclusions: We expect that environmental change will affect seed production and that the phenological relationship with flowering will result in limitations to belowground production and thus affect marsh elevation gain. Salt marshes provide an excellent model system for exploring the interactions between plant ecology and ecosystem functioning, enabling better predictions of climate change impacts. [ABSTRACT FROM AUTHOR]

It has been almost 15 years since concerns about the limited capacity of remnant native vegetation to supply the volumes of seed required to meet increasing restoration demands were first raised. Since that time little progress has been made towards addressing this constraint with the ongoing decline of native vegetation communities, especially since 2000, further challenging seed supply. We provide examples of the size of this demand for seed, as well as major issues associated with seed sourcing. We also discuss how invoking the concept of market forces to drive seed supply and demand is inappropriate and highlight the need for an industry body to oversee seed collection and utilisation standards. We further propose key actions that are required to secure the seed supply chain within the next 20 years to meet existing and future restoration targets. We argue that concerted, coordinated action at Commonwealth, State and regional levels are required to underpin effective future restoration outcomes. [ABSTRACT FROM AUTHOR]

The characteristic of climatic change is increase in the frequency of extreme events that are likely to decrease crop yield. The geographic areas that are currently most food-insecure are likely to be most affected by changing climates. Climate change is likely to affect all dimensions of crop production. Agricultural crop production depends upon the timely availability of good-quality seeds in adequate quantity at affordable prices to the farming communities. Genetic diversity and breeding for improved stress-tolerant genotypes are key elements in tackling climate change. Plant genetic resources (PGRs) are important sources for developing new and improved varieties. The loss of these genetic resources due to climate change will deprive source of diversity and tolerance. Currently, more emphasis has been placed for ex situ conservation, while equally if not more urgency is required to conserve the PGRs in in situ. At present, a number of international agreements are enforced for germplasm exchange and utilization. Some of the important methods to develop and disseminate new cultivars include breeding new crop varieties for wider adaptation under adverse climatic conditions using both classical and modern approaches and seed production through participatory approaches. Participatory breeding programs have successfully led to the development and dissemination of varieties in cereals. Seed industry plays an important role in increasing productivity of crops. The adverse effect of climate change on the seed industry can be minimized by developing efficient seed management systems: breeding, seed production, seed certification, and seed trade. Some efficient systems include adjustment of crop calendars for quality seed production, management of pollinators, strengthening hybrid seed production, postharvest management of seed, seed treatment technologies, seed processing, and seed storage. For faster and timely development, partnerships (public and private) at various levels (regional and international) are crucial. There is an urgent need to strengthen both formal and informal seed systems including characterization of environment to find suitable geographic regions for quality seed production. For seed certification, harmonization of various international seed certification schemes/programs and seed testing procedures are essential. This will also help in efficient and safe movement of seed. To influence seed trade, the effective management of intellectual property rights, sanitary and phytosanitary certificates in addition to management of trade barriers, are all of prime importance for growth of the seed industry. In both developed and developing nations, public investments in plant breeding and seed industry are on the decline. This trend needs to be reversed by emphasizing the need to increase research funding to all stakeholders of genetic resources and seed industry to develop strategies to mitigate the negative impacts of climate change on agricultural systems. [ABSTRACT FROM AUTHOR]

A strong case has been made in many publications for the adoption of highly client-oriented breeding (COB) since a greater role for farmers and clients can help produce and popularise varieties that better meet demands. Participatory varietal selection (PVS) – the testing of a diverse range of new varieties on farm by farmers – is an essential component of COB and has been broadly accepted. However, on the basis of published evidence, other aspects of COB have not been mainstreamed in national and international breeding programmes. This may be because there has been insufficient time for their benefits to become apparent. We review the outcomes from COB in maize ( Zea mays L.) and rice ( Oryza sativa L.) in India that resulted in the official release of a maize variety and two rice varieties. We review the substantial evidence on how all three were better accepted and much more widely adopted in several northern states of India than any of the conventionally bred alternatives that were currently available. This provides the most convincing evidence, so far, that client-oriented methods can be more effective. Prior to this, there was little documentation of the impact of COB programmes with few reports of them producing released varieties, so it may be unsurprising that there has been little institutionalisation of COB. The evidence presented here on its effectiveness ought to provide a stimulus for more breeders to adopt these approaches. However, the question of exactly how much evidence is needed remains rhetorical as evidence-based change is constrained by breeders who, for many reasons, are motivated to preserve the status quo. A greater weight of evidence may have to be accumulated before this inertia is overcome. [ABSTRACT FROM AUTHOR]

Seed system reliability is of major importance in farming. Whereas earlier studies analysed mainly annuals, this study focuses on a perennial. Oil palm in Benin was chosen as a case study because farmers complained about non-hybrids (duraandpisifera) in plots allegedly planted with 100% hybrid (tenera). This study assessed the reliability of the oil palm seedling supply system over past decades and its main drivers. An event ecology approach was used to identify causal mechanisms accounting for the observed variation in oil palm types on smallholder plots. A total of 378 plots belonging to 248 farmers that were allegedly planted withtenerabetween 1969 and 2009 were sampled, and shell thickness of fruits was assessed to determine whether palms weretenera,pisifera,ordura. The proportion ofteneravaried with seedling supply source, farmers' geographic position, seedling purchase price, and year of planting. The proportion ofteneradecreased with year of planting. Socio-institutional mechanisms associated with the observed variation in smallholder plots were national policy change, local arrangements for seedling supply to smallholder farmers, and farmers' personal characteristics. The implications of the observed decrease in the reliability of the seedling supply system are discussed. [ABSTRACT FROM AUTHOR]

The traditional leafy vegetables play a major role in the Cameroonian diet. In the metropolitan zone of Yaoundé, these vegetables are produced year round in family and commercial exploitations. The quality of the seeds, their mode of production and their system of distribution are little known. With the aim to better understand the seed system of traditional vegetables, a study on the supply, the production and the quality of these seeds was carried out. The data were collected using questionnaires on a sample of 133 traditional leafy vegetable producers of the urban and peri-urban zone of Yaoundé. The data were analyzed using SNAP 9 software. The study showed that the most produced species are amaranth (Amaranthus cruentus), nightshade (Solanum scabrum) and jute mallow (Corchorus olitorius). The market-gardeners are influenced in their choice of vegetable to cultivate by the preference of the customers (85.7% of the respondents) and the productivity of the cultivars (66.2% of the respondents). More than 40% of the respondents buy seeds in the markets while 7.5% buy seed from other producers and 10.5% in the agricultural inputs stores. About half (47.4%) of the respondents produce seeds by leaving plants in the field after the first or the second harvest while 36.8% of the market-gardeners select the most vigorous plants for seed production. On average, 58.7% of respondents preserve the seeds in hermetically closed bottles and plastic bag. Storage on field is practiced by a significant part of market-gardeners (41.4%). A total of 79.7% of the producers reported constraints with the produced seeds. Poor seed germination (81.1% of respondents) and the non uniformity of the seed (48.1% of the producers) were reported as the major constraints. The principal source of seed supply in the metropolitan zone of Yaoundé is the self production with rudimentary production and storage techniques subject to many qualitative constraints. [ABSTRACT FROM AUTHOR]

Effects of exclosure management on the plant recruitment are not clear yet. To assess the effects of exclosure management on the recruitment of elm, population structure, seed production, and densities of seeds and seedlings of elm were investigated in fenced and grazed pastures in Horqin Sandy Land, northeastern China. The results showed that seed biomass per branch of elm in the grazed plot was significantly higher than in fenced pasture (0.85 ± 0.27 g vs. 0.55 ± 0.36 g,p < 0.05), and seed density was higher in grazed pasture (845 ± 370 seedsm−2) than that in fenced pasture (558 ± 241 seedsm−2), indicating that grazing would improve reproductive allocation of elm. However, there was no significant difference of seedling density between grazed and fenced pastures. More important, the elm trees with a height less than 0.5 m appeared in the fenced pasture but disappeared in the grazed pasture, indicating the positive effects of exclosure management on the elm recruitment. Our results suggested that the exclosure would favor recruitment of elm through its protection of saplings instead of through increased seed production. This study improves our understanding of the effects of grazing on population dynamics of elm and would contribute to the restoration of degraded sandy land in northern China. [ABSTRACT FROM PUBLISHER]

Semelparous woody bamboos flower fairly synchronously and in clocklike fashion after many years, providing abundant and nutritious seeds. However, this resource is ephemeral, localized, and unpredictable from the perspective of birds that feed on those seeds. Birds specializing on bamboo seeds track this food source and are nomadic. We recorded Temminck's Seedeater (Sporophila falcirostris) at 29 localities and the Buffy-fronted Seedeater (S. frontalis) at 23 localities in Argentina, Paraguay, and southeastern Brazil. In these species, nomadism is unassociated with any seasonal factor: birds may persist year round over several consecutive years if the seed supply is constant enough. Most occurrences and all breeding records were related to masting of bamboo; records of isolated birds away from seeding bamboo must represent individuals searching for bamboo patches. We report winter breeding of these species for the first time and demonstrate that the supply of bamboo seeds is the main limitation to their breeding. On a broad spatiotemporal scale, large-seeded bamboos (e.g., Guadua spp.) may function as strong population pumps, small-seeded bamboos (e.g., Chusquea spp.) as maintenance stations. Both species fed mostly on bamboo seeds, occasionally on bamboo flowers, and rarely on alternative food sources. They consumed insects frequently and occurred in mixed-species flocks, especially during autumn and winter. Creation of a network of protected areas is essential to preserve bamboo patches that flower at different times and localities in sufficiently large quantities to guarantee the long-term survival of the peculiarly dynamic populations of bamboo seedeaters. [ABSTRACT FROM AUTHOR]

A fundamental need for commercialization of sweet sorghum [ Sorghum bicolor (L.) Moench] as a bioenergy crop is an adequate seed supply, which will require development of hybrid varieties using dwarf seed-parent lines. A set of six public sweet sorghum A-lines (Dwarf Kansas Sourless, KS9, N36, N38, N39, and N4692) were crossed with a set of six public sweet sorghum cultivars (Brawley, Kansas Collier, Dale, Sugar Drip, Waconia, and Wray). Grain, fiber, and sugar yields were determined, and conversion formulas were applied to estimate ethanol yields. Hybrids were grown in fields at Ithaca, NE, USA, in 1983-1984 fertilized with 112 kg ha N. In terms of yield components and overall ethanol yields, one A-line, N38, was inferior. Average total ethanol yields from hybrids made on the other A-lines were not significantly different, suggesting that any of those five A-lines could be useful seed-parents. With the exception of grain yield, cultivars used as pollen parents were among the highest-performing entries for all traits. For all traits directly contributing to total ethanol yield (grain yield, juice yield, % soluble solids, sugar yield, fiber yield), hybrids were also among the highest-performing entries. Results of this study demonstrate that hybrid sweet sorghum with performance criteria equivalent to existing sweet sorghum cultivars can be produced on the sweet sorghum seed-parent lines A-Dwarf Kansas Sourless, A-KS9, A-N36, A-N39, and A-N4692. Identification of specific seed-parent × pollen parent lines with characteristics best suited for particular growing regions and end-user needs will be critical for commercial hybrid development. [ABSTRACT FROM AUTHOR]

The potential contributions of new biotechnologies to sustainable food and income security have been the subject of widespread discussions around the turn of the 21st century. But distributional issues of which segments of adopters of genetically modified (GM) crops benefit the most have not been given ample attention). Using propensity scores, we apply the (a) stratification-multilevel method of estimating heterogeneous treatment effects; and the (b) matching-smoothing method of estimating heterogeneous treatment effects proposed by Xie et al. We find that the incidence of higher yields, lower insecticide use, and reduced seed utilization in the Philippines diminishes progressively as a farmer's propensity to adopt Bt corn increases. Farmers with a low propensity to adopt Bt are those who farm smaller, nonirrigated farms located farther from seed suppliers and farmers without previous training on pest identification. In most cases, while these farmers are typically poorer farmers in smaller parcels, cannot afford irrigation and are situated in remote areas away from easily accessible seed suppliers, there is no evidence, however, that profits differ across farmers with varying propensities to adopt the Bt variety. [ABSTRACT FROM AUTHOR]

This paper explores changes in the organization of seed supply in China over the last decade by means of a multi-level institutional analysis. At the landscape level, the implications for China of the regulation of plant genetic resources through various international treaties and conventions are reviewed in the light of the evolution of the global seed industry. At the regime level, the transition in the Chinese context to market-based seed supply and the development of commercial and public seed sectors are examined. The study then analyses trends in seed supply at the niche level, with reference to participatory maize (Zea mays L.) breeding in three provinces in southwest China where high rural poverty persists. This work offers radical novelty in variety development and seed provision on behalf of smallholder farmers. However, a series of technical, organizational and market ‘mismatches’ are demonstrated within the existing seed regime. The participatory work emphasizes breeding for diverse cultivars adapted to specific ecosystems but these are prevented from reaching commercial markets by existing varietal testing procedures. Participatory breeding has potential to address farmers’ varietal needs as agriculture modernises and to support the public function of research institutes, but within mainstream intellectual property regimes the public value of participatory breeding cannot be accommodated adequately. Yet, when coupled to institutional innovations for recognising intellectual property and sharing benefit among all those who contribute, participatory breeding may initiate a powerful dynamics for change within seed regimes and a sui generis seed system suited to the Chinese context. [ABSTRACT FROM AUTHOR]

Abstract: This paper evaluates the potential impact of adoption of improved legume technologies on rural household welfare measured by consumption expenditure in rural Ethiopia and Tanzania. The study utilizes cross-sectional farm household level data collected in 2008 from a randomly selected sample of 1313 households (700 in Ethiopia and 613 in Tanzania). The causal impact of technology adoption is estimated by utilizing endogenous switching regression. This helps us estimate the true welfare effect of technology adoption by controlling for the role of selection problem on production and adoption decisions. Our analysis reveals that adoption of improved agricultural technologies has a significant positive impact consumption expenditure (in per adult equivalent terms) in rural Ethiopia and Tanzania. This confirms the potential role of technology adoption in improving rural household welfare as higher consumption expenditure from improved technologies translate into lower poverty, higher food security and greater ability to withstand risk. An analysis of the determinants of adoption highlighted inadequate local supply of seed, access to information and perception about the new cultivars as key constraints for technology adoption. [Copyright &y& Elsevier]

We examined the density and composition of the immediate seed supply (i.e. instant potential post-fire germination from soil seed bank and off-site seed rain) after a large wildfire in a sub-Mediterranean pine forest. We also tested the effects of fire severity and distance from unburned edges on the density and composition of the seed bank and the immediate off-site seed rain. Our results showed that although seed density did not differ between them, their composition was markedly different. The soil seed bank was dominated by species from the Fabaceae family with limited dispersal mechanisms such as autochory and barochory, whereas the seed rain was mainly composed of species from the Asteraceae family with wind-dispersed seeds. These patterns were not affected either by fire severity or distance from the fire edge. The main conclusion of the study is that both the soil seed bank and the seed rain play an important role in providing seeds for immediate regeneration after a large wildfire throughout the burned area. We suggest that the role of seed rain on immediate post-fire recovery of Mediterranean plant communities might be more important than has previously been thought. However, the effective role of this group of species on the longer term should be evaluated. We examined the immediate seed supply after a large wildfire by comparing soil seed bank and off-site seed rain. Although seed density did not differ between them, their species composition was markedly different, and these patterns were not affected either by fire severity or distance from the fire edge. [ABSTRACT FROM AUTHOR]

There is a growing consensus that the relative constraints of seed limitation and establishment limitation in recruitment strongly influence abundance patterns in plant communities. Although these constraints have direct relevance to coexistence, most investigations utilize a seed addition approach that offers limited insight into these dynamics. Here we report the results of an assembly experiment with annual plant species from California grasslands to examine how propagule pool characteristics (dominant species abundance, functional diversity) influence establishment and seed limitation (density independence and density dependence across a gradient of seed supply) for each species, as well as how these constraints affect community diversity. Species were predominantly colimited by seed and establishment constraints, exhibiting saturating recruitment functions with increased seed supply. Consistent with competitioncolonization trade-off predictions, recruitment constraints often depended on the degree of seed limitation of the competitive dominant, Brassica nigra; diversity was greatest in communities where Brassica was seed limited. Functional similarity within the propagule pool did not affect recruitment across a range of seed supply; likewise, functional diversity of the propagule pool was not related to community diversity. We conclude that seed limitation of the dominant species rather than niche similarity influences interspecific competition for safe sites and scales up to affect community-level diversity. [ABSTRACT FROM AUTHOR]