Unleashing the power of cassava: new cassava varieties for Africa   Unleashing the power of cassava: new cassava varieties for Africa Alfred G.O. Dixon et al. International Institute of Tropical Agriculture (IITA), PMB 5320 Ibadan, Nigeria

Africa Confronted with a rapidly growing population and rising urbanization Parallel increase in demand for food, feed for livestock, and raw materials for industries

Collaborate study of Cassava in Africa (COSCA) Lessons learnt Collaborate study of Cassava in Africa (COSCA) Field production costs (cost of planting materials and field operations’ labor per unit weight of output) declines as yield increases because most of such costs are constant per unit area, irrespective of the yield Costs per unit weight of output: constant as yield increases, because the processing technique employed is manual with a low level of capital investment Restricted market opportunities for the final products and expanded production impeded by high cost of production, and product qualities both of which are results of dependence on traditional production and processing technologies Reliable markets will greatly increase yields of improved varieties of cassava as farmers will pay more attention to their crop Don’t solve problems alone, capitalize on opportunities

Future of Africa’s cassava sub-sector can follow two pathways Surplus cassava products find no market Subsistence farming Very limited adoption and impact of technologies 2. Markets available for surplus cassava products More of a cash crop Technologies readily adopted with large impact at producer and consumer levels

Production Orientation Improved cassava varieties responsive to markets will drive down costs of production, harvesting, processing and marketing Improve the quantity and quality of cassava products for diversified uses Make cassava products competitive with other raw materials Production Orientation Assumes market demand exists for increased production Entry point for research agenda is prioritization of production constraints Market Orientation Market is the driver No assumption necessary Entry point for research agenda is the identification of market opportunities

Genetic improvement Breeding Paradigm Developing varieties that are responsive to changing demands Requires knowledge of producers to consumers’ continuum Require application of modern science and technology and conventional breeding, as well as increased partnerships Breeding Paradigm Phenotype = Genotype x Environment x Crop Management x Policy x Institutions x People

Varieties for Africa in the next decade Gear the crop to more efficient production, postharvest and marketing operations Attract urban consumers and industries Create demand for the crop Stimulate increased production Provide more income for producers, processors, and traders WHAT will WE do Today that will MATTER Tomorrow

Varieties for the next decade multiple sources of resistant genes for emerging pest threats for durable resistance high storage root starch quantity per unit area and time, and quality, for food, feed, and agro-industrial uses enhanced nutritional content of storage roots (high protein and micronutrient contents) delayed onset or deactivation of physiological postharvest deterioration (PPD) of storage roots Acyanogenesis to reduce costs of processing, enhance nutrient bioavalability and or to prevent setback in cassava global market

drought resistance as cassava expands to non-traditional areas and in the light of global climate change nutrient use efficiency herbicide resistance for durable weed control (e.g. round-up ready resistant cassava) good plant architecture for ease of mechanized operations and ease of processing high root and foliage yield (dual purpose cassava) for food and feed

Addressing the limitations of the Crop Bulkiness of edible crop portion and plant propagule which has implications for handling, transport, storage, crop hygiene Perishability of the edible crop product and plant propagule which has implications for marketing, utilization, and crop management Low multiplication ratio of plant propagules using standard propagation techniques, which has implications for area planted per unit time

Efficiency and effectiveness tools Shortened breeding cycle and robust seed production methods (e.g. double haploids for rapid production of homozygous lines, pure hybrid seed production, apomixes) Profuse flowering at will” to access a greater diversity of parental materials Development of effective molecular markers to optimize the use of genetic resources and in marker-aided introgression/selection Genotype neutral and efficient transformation and regeneration system Rapid, and cheap molecular diagnostic tools for important diseases to ensure the safe movement of germplasm Cheaper and robust rapid multiplication of planting material

Location of cassava gene sources World collection at CIAT = Ca 6000 IITA Collection Field bank - Manihot esculenta: 3078 accessions with passport data - In vitro bank = 2300 accessions National collections = variable numbers Embrapa collection not already in world collection

Different cassava ß-carotene root types Sources of genes 5 10 15 20 25 36 37 38 39 40 41 42 43 44 45 46 47 48 49 Dry matter percentage Number of clones Dry matter distribution among selected genotypes Delayed PPD in F1 Hybrid of M. walkerae 14 days after harvest CW 429-1: 0% Different cassava ß-carotene root types CM 523-7: 51.9%

Potential performance of the top 3 genotypes in various on-station trials in E. Africa d Clone RTNo a e F.Yield b D.Yield c DM CNP Rubona, Rwanda MM96/3733 91 75.5 34.0 45.1 50.8 MM96/5526 97 89.0 33.7 37.9 95.0 MM96/3318 137 67.5 28.9 42.9 70.6 Serere, Uganda MM96/5373 85 58.4 24.1 41.3 141.0 MM96/1642 75 55.9 22.7 42.0 189.0 MM96/2649 90 59.3 21.6 36.4 227.0 Alupe, Kenya Just wished farmers get these yields on their farms MM96/5280 132 217.2 – – – MM96/1871 98 194.0 – – – MM96/7151 92 191.6 – – – Mtwapa, Kenya LL97/0604 143 50.7 – – – LL97/0290 137 41.8 – – – LL97/0727 135 36.0 – – – aNumber of storage roots/plot; bFresh storage root yield (t/ha); cDry storage root yield (t/ha); dPercentage dry matter; eCynogenic potential (mg HCN eq./dry weight of storage root).

Technology will go nowhere without the markets Re-think what helps the poor most

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