Innovation in seed potato systems in Eastern Africa

Keywords: Potato, positive selection, viruses, seed potato systems, East Africa, Kenya, Uganda, Ethiopia Potato (Solanum tuberosum L.) is a crop with a high potential to contribute to poverty reduction in Eastern Africa through income increase and improved food security. It is largely grown by smallholders, has a high production per hectare, stable prices and a steadily growing demand. Average yields in Eastern Africa of 10.5 t/ha are much below the world average and yields observed in the fields of better performing smallholders. There is both a need and a potential for increased potato productivity. A diagnosis of the potato systems of Kenya, Uganda and Ethiopia identified integrated management of bacterial wilt (Ralstonia solanacearum) and late blight (Phytophthora infestans), soil fertility management, and improving seed potato quality as technology-based opportunities for innovation. Improvement of potato supply chains and the knowledge exchange in the sector were identified as systemic opportunities for improvement. Analysis of the seed potato system confirms that both virus diseases and bacterial wilt are likely contributors to the low yields. In only 3% of seed potato tubers sold in rural markets was free of PVY, PLRV, PVX and PVA. Ralstonia solanacearum was found in 74% of potato farms sampled in Kenya. Less than 5% of the seed potatoes used are sourced from specialized multipliers (specialized chain). Farmers rely on seed potatoes from neighbours and farm-saved seed potatoes (local chain). This often makes economic sense in the absence of affordable high quality seed potatoes and limited market security. Seed potato system interventions need to tackle the local and specialized chain simultaneously. Private investment in specialized multiplication could stimulate the production of affordable high-quality seed potatoes. For local chain improvement training on seed quality maintenance and on bacterial wilt and virus management is needed. Research into the mitigation of yield-reducing effects of indiscriminate seed potato recycling, such as research on virus resistance and positive selection deserves attention. Positive selection, the selection of healthy looking mother plants for the production of seed potatoes, can contribute to improving quality management in the local chain. In farmer managed trials in Kenya it gave an average yield increase of 34% which corresponded to a 284 Euro profit increase per ha. It requires no cash and only 4 man-days 12 per hectare and is an important alternative and complementary technology to regular seed replacement. In 18 replicated trials it was shown that positive selection lowered the incidence of PLRV, PVY and PVX with 35%, 35% and 39%, respectively, and increased yields irrespective of the agro-ecology, crop management, soil fertility, variety, and quality of the starting material with an average 30%, compared to current farmer practice. Regression analysis showed that this reduction in virus incidence contributed to the higher yields, but did not fully account for the effect. Probably other, not tested, virus diseases and other seed borne diseases also played a role. It can be concluded that positive selection can benefit all smallholder potato producers who select seed potatoes from their own fields, and should thus be incorporated routinely in agricultural extension efforts. In retrospect the research trajectory can be considered a successful contribution of agricultural research to innovation. It shows that it is worthwhile to search for opportunities for incremental innovation that do not require institutional change and that these opportunities can be of a surprising simple nature, and based on old technology. Essential for researchers to contribute to innovation is room to manoeuvre and opportunity to immerse in practical collaborative partnerships with practitioners. Most importantly, innovation needs to be made a central objective, rather than research results, and the mandate of research needs to be broadened and allow for the active engagement in training, communication and scaling-up. </p

The role of innovation brokers in agricultural innovation systems

Managing the ability of agriculture to meet rising global demand and to respond to the changes and opportunities will require good policy, sustained investments, and innovation - not business as usual. Investments in public Research and Development, extension, education, and their links with one another have elicited high returns and pro-poor growth, but these investments alone will not elicit innovation at the pace or on the scale required by the intensifying and proliferating challenges confronting agriculture. Experience indicates that aside from a strong capacity in Research and Development, the ability to innovate is often related to collective action, coordination, the exchange of knowledge among diverse actors, the incentives and resources available to form partnerships and develop businesses, and conditions that make it possible for farmers or entrepreneurs to use the innovations. While consensus is developing about what is meant by 'innovation' and 'innovation system', no detailed blueprint exists for making agricultural innovation happen at a given time, in a given place, for a given result. The AIS approach that looks at these multiple conditions and relationships that promote innovation in agriculture, has however moved from a concept to a sub-discipline with principles of analysis and action. AIS investments must be specific to the context, responding to the stage of development in a particular country and agricultural sector, especially the AIS. This sourcebook contributes to identifying, designing, and implementing the investments, approaches, and complementary interventions that appear most likely to strengthen AIS and to promote agricultural innovation and equitable growth. It emphasizes the lessons learned, benefits and impacts, implementation issues, and prospects for replicating or expanding successful practices. The information in this sourcebook derives from approaches that have been tested at different scales in different contexts. It reflects the experiences and evolving understanding of numerous individuals and organizations concerned with agricultural innovation, including the World Bank. This information is targeted to the key operational staff in international and regional development agencies and national governments who design and implement lending projects and to the practitioners who design thematic programs and technical assistance packages. The sourcebook can also be an important resource for the research community and nongovernmental organizations (NGOs)

Seed potato quality improvement through positive selection by smallholder farmers in Kenya

In Kenya, seed potato quality is often a major yield constraint in potato production as smallholder farmers use farm-saved seed without proper management of seed-borne pests and diseases. Farm-saved seed is therefore often highly degenerated. We carried out on-farm research to assess whether farmer-managed positive seed selection could improve yield. Positive selection gave an average yield increase in farmer-managed trials of 34%, corresponding to a 284-€ increase in profit per hectare at an additional production cost of only 6€/ha. Positive selection can be an important alternative and complementary technology to regular seed replacement, especially in the context of imperfect rural economies characterized by high risks of production and insecure markets. It does not require cash investments and is thus accessible for all potato producers. It can also be applied where access to highquality seed is not guaranteed. The technology is also suitable for landraces and not recognized cultivars that cannot be multiplied formally. Finally, the technology fits seamlessly within the seed systems of Sub-Saharan Africa, which are dominated by self-supply and neighbour supply of seed potatoes

Improving seed health and seed performance by positive selection in three Kenyan potato varieties

Selecting seed potatoes from healthy-looking mother plants (positive selection) was compared with common Kenyan farmer practice of selection from the harvested bulk of potatoes (farmer selection) in 23 farmer-managed trials. Positive selection assured lower incidences of PLRV (39%), PVY (35%) and PVX (35%). Positive selection out-yielded farmer selection irrespective of the agro-ecology, crop management, soil fertility, variety and quality of the starter seed, with an overall average of 30%. Regression analysis showed a relation between lower virus incidence and higher yield for the varieties. The paper discusses the consequences for seed system management in African countries. Furthermore possible additional effects of positive selection are discussed and further research is suggested. The paper concludes that positive selection can benefit all smallholder potato producers who at some stage select seed potatoes from their own fields, and should thus be incorporated routinely in agricultural extension efforts