linked to soil properties and changes in crop management practices (Alabouvette et al., 2004)
.      The loss of broad-spectrum biocides, namely methyl bromide, has created opportunities for investigating new directions in managing root diseases. Synthetic substitutes, such as chloropicrin and metam sodium, are generally less effective than methyl bromide, can cause increased germina­tion of nutsedge and others weeds (Martin, 2003), and pose substantial health risks to farm workers and adjacent com­munities (MMWR, 2004).
     Biocontrol of soilborne pests and pathogens will likely continue to succeed on the experimental level, and yet still have only limited impact on field-based commercial applica­tions of biocontrol until impediments to scaling up biocon­trol are addressed. These include the exceedingly high costs of registration, and lack of private sector investment (Fravel, 2005). The recent success in scaling up nematode biocon­trol using a nonpathogenic strain of Fusarium oxysporum to control the highly destructive Radopholus similis, causal agent of banana toppling disease (Sikora and Pokasangree, 2004), illustrate how the alignment of multiple factors— a very effective biocontrol agent, a highly visible disease problem with significant economic impact, and substantial private-sector investment—was necessary to allow for de­velopment of a potential commercial product.
     Long-term and stable organic production systems gen­erally have less severe root disease problems than conven­tionally managed systems; however, the specific mechanisms that lead to soilborne disease suppression remain poorly un­derstood (van Bruggen and Termorshuizen, 2003). Given that soilborne pests and disease play a role in the produc­tivity dip associated with the transition from conventional to organic production, greater attention towards developing indicators of root disease suppression would help to better address development and sustainability goals.

6.1.4 Value chains, market development
Although reduction of post-harvest losses has been an im­portant focus of AKST and development programs in the past, in many cases the technical innovations faced so-ciocultural or socioeconomic problems such as low profit margins, additional workload or incompatibility with the existing production or postproduction system (Bell et al., 1999). The divergence between technical recommendations and the realities of rural life translated in many cases into low adoption rates.
     In specific cases, large shares of food produced are lost after harvest. Yet, the rationale for improvements in the postharvest systems has been shifting from loss preven­tion (Kader, 2005) to opening new markets opportunities (Hellin and Higman, 2005). Making markets work for the poor (Ferrand et al., 2004) is emerging as the new rationale of development, reflecting a shift away from governmental operation of postharvest tasks to enabling frameworks for private sector initiatives in this field (Bell et al., 1999).

Research and capacity development needs. Increasing at­tention is being placed on value and market-chain analy­sis, upgrading and innovation. Processing, transport and marketing of agricultural products are increasingly seen as a vertical integration process from producers to retailers,

to reduce transaction costs and improve food quality and safety (Chowdhuri et al., 2005).
     In market-chain analysis, some of the challenges include improving small-scale farmer competitiveness and farmers' organizations (Biénabe and Sautier, 2005); institutional ca­pacity building (especially access to information)  (Kydd, 2002); and the reinforcement of links and trust among ac­tors in the market chain (Best et al., 2005).
      Demand driven production asks for improved mar­ket literacy of producers as a prerequisite for access to su­permarkets, a challenge especially for small-scale farmers (Reardon et al, 2004; Hellin et al., 2005). Building trust among the stakeholders in the market chain is a crucial com­ponent of vertical integration (Best et al., 2005; Chowdhury et al., 2005; Giuliani, 2007). It enhances transparency of the market chain and exchange of information. Typically, actors in the market chains are at first skeptical about infor­mation sharing; when they realize that all can benefit from more transparency along the market chain they more read­ily provide information. Maximizing added value at farm or village level is a promising option for small-scale farm­ers; rural agroenterprises and household level processing can increase income generation (Best et al., 2005; Giuliani, 2007).
      The  creation  of community-based   organizations   or farmers groups can result in economies of scale. Collectively, small-scale farmers are able to pool their resources and mar­ket as a group, hence reducing transaction costs (Keizer et al., 2007). It can improve their access to resources such as inputs, credit, training, transport and information, increase bargaining power (Bosc et al., 2002) and facilitate certifica­tion and labeling.
      Better market access is often a key concern of small-scale farmers (Bernet et al., 2005). Promising market op­tions directly linked to rural poor small-scale producers and processors include fair-trade channels, private-public partnership, and the creation of local niche markets (eco-labeling, certification of geographical indications of origin, tourism-oriented sales outlets, etc.). Crops neglected so far by formal research and extension hold promise for upgrad­ing value chains (Hellin and Highman, 2005; Gruère et al., 2006; Giuliani, 2007) in which small-scale farmers have a comparative advantage.
      Value-chain analysis investigates the complexity of the actors involved and how they affect the production-to-con­sumption process. It incorporates production activities (cul­tivation, manufacturing and processing), non-production activities (design, finance, marketing and retailing), and governance (Bedford et al., 2001). The analysis of liveli­hoods of small-scale producers, processors and traders and their current and potential relation to markets is a starting point in ensuring that markets benefit the poor. Analyzing the market chain and the requirements and potentials of all its actors allows for identifying interventions along the chain likely to provide benefits to low-income households (Giuliani, 2007).
      Investments in value chain research have the potential to improve equity by opening up income opportunities for small-scale farmers. The challenge will be to make small-scale farmers competitive and to identify opportunities and develop value chains which build on their potential (labor