Epidemic networks and potential sources of bacterial wilt infection in a potato seed network in Kenya.

Potato seed systems in Kenya are largely informal, characterized by high seed degeneration due to the buildup of seed- and soil-borne diseases, including bacterial wilt caused by Ralstonia solanacearum. Informal sources of seed include neighbors, local markets and farmer-saved seed, and present a risk for spread and establishment of disease. To understand the larger context of potato disease risk in Kenya, we used network analysis to evaluate (1) epidemic risk through potato trade networks centered around East Africa, and (2) locations in East Africa likely to be particularly important for epidemic management because of their high potato cropland connectivity. We evaluated the interactions of the key stakeholders in a potato seed system and used network analysis to identify locations that are likely to be important for the spread of infection of R. solanacearum in a potato seed distribution network in Meru, Kenya. Household details, seed sources, quantities sold, pest incidence and management practices, knowledge about seed degeneration and farmers' sources of information on potato production were obtained and analyzed. The survey revealed that self-saved, neighbors, seed companies, friends, exchange, and markets are the main seed sources. Only 43% of total seed transacted was certified. Users of uncertified seeds have high disease risk, and this is an especially important risk if their roles in the network give them the potential to be 'superspreaders' of disease.

Capacities of local maize seed enterprises in Mexico: Implications for seed systems development

Where maize plays a critical role in food security, governments and donors have invested heavily in support of local, privately owned, often small and medium sized, maize seed enterprises (maize SMEs). Underpinning these investments are strong assumptions about maize SMEs’ capacity to produce and distribute seed to smallholders. This study assesses the capacities of 22 maize SMEs in Mexico that engaged with MasAgro—a large-scale development program initiated in 2011 that has provided maize SMEs with improved genetic material and technical assistance. Data were collected onsite from in-depth interviews with enterprise owners and managers and complemented with other primary and secondary sources. Overall, maize SMEs showed high levels of absorptive capacity for seed production, but limited signs of learning and innovation in terms of business organization and strategic seed marketing. Asset endowments varied widely among the SMEs, but generally they were lowest among the smaller enterprises, and access to business development services beyond MasAgro was practically nonexistent. Results highlighted the critical role of MasAgro in reinvigorating the portfolios of seeds produced by maize SMEs, as well as the challenges ahead for maize SMEs to scale the new technologies in a competitive market that has long been dominated by multinational seed enterprises. Among these challenges were limited investment in seed marketing, weak infrastructure for seed production, and limited experience in business management. Achieving the food security goals through maize SMEs will require making national maize seed industry development a strategic imperative.

It ain't what you do, it's what drives why you do it: how the basis of growers' decision making affects the effectiveness of disease control

While the spread of plant disease depends strongly on biological factors controlling transmission, epidemics clearly also have a human dimension. Disease control depends on decisions made by individual growers, who are in turn influenced by a broad range of factors. Despite this, human behaviour has rarely been included in plant epidemic models. Considering Cassava Brown Streak Disease, we model how the perceived benefit of disease control influences participation in clean seed systems (CSS). Our models are rooted in game theory, with growers making strategic decisions based on the expected profitability of different control strategies. We find that both the information used by growers to assess profitability and the perception of economic and epidemiological parameters influence long-term participation in the CSS. Over-estimation of infection risk leads to lower participation in the CSS, as growers perceive that paying for the CSS will be futile. Additionally, though the CSS can reduce the burden of disease, and allow a scenario in which all growers control, disease is not eliminated from the system. These results are robust to stochastic and spatial effects. Our work highlights the importance of including human behaviour in plant disease models, but also the significance of how that behaviour is included.

Spatial parameters associated with the risk of banana bunchy top disease in smallholder systems

The Banana Bunchy Top Disease (BBTD), caused by the Banana Bunchy Top Virus (BBTV) is the most important and devastating in many tropical countries. BBTD epidemiology has been little studied, mixed landscape smallholder systems. The relative risks associated with this disease vary between geographical areas and landscapes. This work analyzed the management and vegetation conditions in smallholder gardens to assess the factors linked to landscape-level BBTV transmission and management. Mapping was done in this study area which is in a BBTD-endemic region, involving farmers actively managing the disease, but with household-level decision making. A spatial scanning statistic was used to detect and identify spatial groups at the 5% significance threshold, and a Poisson regression model was used to explore propagation vectors and the effect of surrounding vegetation and crop diversity. Spatial groups with high relative risk were identified in three communities, Dangbo, Houéyogbé, and Adjarra. Significant associations emerged between the BBTD prevalence and some crop diversity, seed systems, and BBTD management linked factors. The identified factors form important candidate management options for the detailed assessment of landscape-scale BBTD management in smallholder communities.

The phytosanitary risks posed by seeds for sowing trade networks

When successful, the operation of local and international networks of crop seed distribution or “seed systems” ensures farmer access to seed and impacts rural livelihoods and food security. Farmers are both consumers and producers in seed systems and benefit from access to global markets. However, phytosanitary measures and seed purity tests are also needed to maintain seed quality and prevent the spread of costly weeds, pests and diseases, in some countries regulatory controls have been in place since the 1800s. Nevertheless, seed contaminants are internationally implicated in between 7% and 37% of the invasive plant species and many of the agricultural pests and diseases. We assess biosecurity risk across international seed trade networks of forage crops using models of contaminant spread that integrate network connectivity and trade volume. To stochastically model hypothetical contaminants through global seed trade networks, realistic dispersal probabilities were estimated from quarantine weed seed detections and incursions from border security interception data in New Zealand. For our test case we use contaminants linked to the global trade of ryegrass and clover seed. Between 2014 and 2018 only four quarantine weed species (222 species and several genera are on the quarantine schedule) warranting risk mitigation were detected at the border. Quarantine weeds were rare considering that average import volumes were over 190 tonnes for ryegrass and clover, but 105 unregulated contaminant species were allowed in. Ryegrass and clover seed imports each led to one post-border weed incursion response over 20 years. Trade reports revealed complex global seed trade networks spanning >134 (ryegrass) and >110 (clover) countries. Simulations showed contaminants could disperse to as many as 50 (clover) or 80 (ryegrass) countries within 10 time-steps. Risk assessed via network models differed 18% (ryegrass) or 48% (clover) of the time compared to risk assessed on trade volumes. We conclude that biosecurity risk is driven by network position, the number of trading connections and trade volume. Risk mitigation measures could involve the use of more comprehensive lists of regulated species, comprehensive inspection protocols, or the addition of field surveillance at farms where seed is planted.

Editorial introduction: Design issues and practical questions for demand-oriented seed systems

This special issue is a collection of papers that brings together different views on and experiences with seed systems and reflects the breadth of perspectives within CGIAR and beyond. The contributions relate to the major challenges facing seed systems research and development in different contexts and for different crops. One point of agreement among these articles is the need for the development of varieties and the delivery of seeds to be more demand-orientated. This introduction reflects on the implications for CGIAR and affiliated breeding programmes which aim to accelerate varietal uptake and turnover and rely on more effective seed delivery. Here, we outline how the various contributions in this special issue relate to this agenda. We conclude that realism about which farming households can be served by current approaches to seed system development is needed and argue that a wider range of partnerships will be required to broaden the reach of seed systems.

International Aid for Agricultural Development of Timor-Leste

Background: The Democratic Republic of Timor-Leste is the newest nation in the 21st century, which became independent in 2002. Yet continued violent tensions kept the country from stabilizing its sociopolitical situations and it remains as a least developed country with many challenging issues, including food/nutrition insecurity. The international community has been supporting Timor-Leste to ameliorate it by aiding the agricultural development of the country. Objective: The objective of this study is to examine the aid profile of the donors for Timorese agricultural development. The findings of the study intend to provide the Timorese government and donors with a useful dialogue point for more efficient collaboration. Methods: The aid data reported to the Creditor Reporting System are sorted for the profile examination. The analysis is based on the aid disbursement between 2002 and 2019. Results: Australia was the largest donor, mostly shaping the agricultural aid profile of the donors. Japan, USA, and New Zealand were the major donors in that order, following Australia. Yet, their prioritized sub-sectors or interests appeared to vary; Australia prioritized strengthening Timorese seed systems and focused on nutrition-sensitive agriculture, Japan emphasized rice production, USA was mainly interested in cash/horticultural crops value chains, and New Zealand invested mainly in agricultural cooperatives. Of the multilateral organizations, the European Union was the principal donor. Conclusion: The Timorese government and donors may need a strategic collaboration to utilize available resources more efficiently as its food/nutrition insecurity is rooted in complex issues and improving it also hinges on development of other sectors.

Regulating Seeds—A Challenging Task

Seed is an essential start of any crop production. Seed, as both botanical seed and vegetive planting materials, is thus a very important component of agricultural livelihoods in food, ornamental, and industrial value chains, of local and global food security, and a determinant of sustainability. All farmers need good seed, irrespective of the farming system and markets that they supply. Seed qualities, in terms of germination/vigour, health, and genetic content, are a concern of all farmers. Farmers have various ways to access seeds. With time, the diversity of farmers’ and formal seed systems have become increasingly refined and complex. Given the importance of seed, not just for farmers but for society at large, seeds have become subject to an increasing number of regulations that pursue different policy objectives. Some have been intentionally developed to regulate seed systems themselves, while others impact them as a side effect. Various components of different policies, regulations and outcomes, their interactions and apparent dilemmas and inconsistencies are discussed to highlight the significance of seeds and to illustrate the importance for policymakers and regulators to carefully phrase rules and be sensitive toward the possible unintended effects of their actions. This particularly relates to seed marketing regulations, intellectual property and farmers’ rights, and biodiversity and biosafety rules. A general conclusion is that rules and regulations need to respond to evolving technical and socio-economic developments. Since seed systems differ widely and operate side by side, regulating a particular system may negatively impact others. The challenge for policymakers is to create policies and regulations that support both formal and farmers’ seed systems where they are most effective while minimalising negative consequences for breeding, selection, and seed production in either system. Several suggestions and recommendations for how to do so are provided in this special issue.

Advances in the Registration of Farmers’ Varieties: Four Cases from the Global South

Over the last few decades, there has been a growing appreciation of crop varieties developed by local farmers, commonly referred to as farmers’ varieties. These varieties often have attractive characteristics for both producers and consumers, such as adaptability to harsh environmental conditions and high nutritional values. Yet they are usually not sold in formal markets, and tend to be limited to farmers’ seed systems. This is partially due to national seed laws that, in an effort to guarantee good quality seed of uniform and stable varieties, create obstacles for farmers’ varieties to reach the market. This article describes the experiences of four countries—Bolivia, Laos, Nepal and Zimbabwe—that are developing alternative variety registration systems for farmers’ varieties. Most of these cases have never been documented before. The cases present the main drivers behind and approaches to the registration of farmers’ varieties in different legal contexts and at different stages of development. We conclude that farmers’ variety registration systems can generate benefits including faster and cheaper variety releases, improved farmer incomes, and a larger diversity of well-adapted varieties in the market—but some important issues are still to be resolved.

Politics of Seed in Ethiopia's Agricultural Transformation: Pathways to Seed System Development

Seed system development in the developing world, especially in Africa, has become a political space. This article analyzes current Ethiopian seed politics in light of the historical dynamics of national and international seed system politics and developments. Drawing on multiple power analysis approaches and employing the lens of “international seed regimes,” the article characterizes the historical pattern of seed regimes in Ethiopia. While colonial territories underwent three historical seed regime patterns—the first colonial seed regime, the second post-WWII public seed regime, and the third post-1980s corporate-based neoliberal seed regime, Ethiopia has only experienced one of these. Until the 1950s, when the first US government's development assistance program—the Point 4 Program—enabled the second government-led seed regime to emerge, the farmers' seed systems remained the only seed innovation and supply system. The first colonial seed regime never took hold as the country remained uncolonized, and the government has hitherto resisted the third corporate-based neoliberal seed regime. In the current conjuncture in the contemporary Ethiopian seed regime, four different approaches to pluralistic seed system development are competing: (1) government-led formalization, (2) private-led formalization, (3) farmer-based localization, and (4) community-based integrative seed system developments. The Pluralistic Seed System Development Strategy (PSSDS) from 2013 is a uniquely diverse approach to seed system development internationally; however, it has yet to realize its equity and sustainability potential. This study shows that the agricultural modernization dependency and government-led formal seed systems development have sidelined opportunities to tap into the strength of other alternatives identified in the PSSDS. In conclusion, an integrative and inclusive seed sector is possible if the government takes leadership and removes the current political, organizational, and economic barriers for developing a truly pluralistic seed system.