59 Chapters
Medium 9781780644202

9: Integrative Breeding Strategy for Making Climate-smart Potato Varieties for Sub-Saharan Africa

Low, J. CABI PDF

9 

Integrative Breeding Strategy for Making Climate-smart Potato

Varieties for Sub-Saharan Africa

1

A. Asfaw,1* M. Bonierbale2 and M.A. Khan2

International Potato Center (CIP), Nairobi, Kenya; 2CIP, Lima, Peru

Abstract

Breeding potato (Solanum tuberosum L.) is becoming increasingly complicated because of the growing number of requirements for new varieties, particularly the added concern of adapting potato to climate variability, especially in regions of sub-Saharan Africa. Combining the right genes to overcome constraints of climate variability in a potato crop, together with an enhanced level of other desirable traits such as consumer and commercial preferences, yield and resistance to biotic stresses requires an integrated breeding strategy that makes use of the knowledge of scientists as well as farmers. This chapter discusses the design of a breeding strategy that incorporates adaptation traits with the commercial and home-use characteristics preferred by potato farmers for varieties to be grown in diverse environments.

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Medium 9781780644202

4: Development and Evaluation of New Sweetpotato Varieties through Farmer Participatory Breeding for High Altitudes in Kenya

Low, J. CABI PDF

4 

Development and Evaluation of New Sweetpotato Varieties through

Farmer Participatory Breeding for High Altitudes in Kenya

L. Karanja,* J. Malinga, J. Ndung’u, A. Gichangi,

D. Lelgut and J. Kamundia

Kenya Agricultural and Livestock Research Organization (KALRO),

Njoro, Kenya

Abstract

Sweetpotato (Ipomoea batatas L.) plays a significant role in food and nutritional security in Kenya.

However, production is constrained by: (i) Sweet potato virus diseases (SPVD) and weevils (Cylas spp.); (ii) shortage of clean planting materials; (iii) lack of suitable varieties for high altitude agroecosystems; (iv) poor postharvest handling; and (v) poor market access. In order to enhance the role of sweetpotato for food security, a breeding programme was initiated at Kenya Agricultural Research Institute (KARI)-Njoro with the objective of developing varieties with desirable genetic and agronomic attributes which include high yields, resistance to SPVD and weevils, improved food quality, and market acceptability for high altitudes. Thirty-six potential parents were identified in initial screening of 440 accessions from landraces, improved and imported accessions. Hand and polycrossing ­process was performed to generate a breeding nursery of 2200 seedlings. Forty-three entries were identified for advancement to preliminary yield evaluation. Out of these, ten entries were advanced to multi-location testing in five sites under the oversight of the National Performance Trials committee. The multi-location trials were conducted on a randomized complete block design with three replicates at Kabianga (LH1-1745 m above sea level (masl)), Ravine (LH3-2167 masl), KARI-Lanet (LH4-1920 masl), Lare (LH4-1900 masl) and KARI-Njoro (LH3-2166 masl). The sites were in the Central Rift Valley region. Participatory variety evaluation by researchers, extensionists, plant regulators and farmers was adopted in all the trials. Standard operating procedures and analyses as prescribed by the International Potato Center and the Kenya Plant Health Inspectorate Service were used to evaluate: (i)  yields; (ii) viruses and weevils; (iii) dry matter content;

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49: Sweetpotato Value Chain Development in West Africa: Matching Products with Farmer Typology

Low, J. CABI PDF

49 

Sweetpotato Value Chain

Development in West Africa: Matching

Products with Farmer Typology

D. Peters*

Baltimore, Maryland, USA

Abstract

Sweetpotato value chain studies conducted in 2012 in three West African countries – Ghana, Nigeria and Burkina Faso – indicated three types of sweetpotato producers. Type I farmers specialize in sweetpotato production, making it the most important cash crop for their farm. Type II farmers grow sweetpotato as one of the cash crops and sweetpotato may rank second or third among these cash crops. Type III farmers are those who grow it mainly for home consumption though still sell a part of the roots due to perishability. The marketing assessment indicated three potential product value chains worth developing, each appropriate for different types of producers.

The fresh root value chain is well suited for Types I and II farmers for obvious reasons. Potential interventions to improve the system include: (i) breeding/selection of high-yielding varieties with the characteristics acceptable to the markets; (ii) best practices for production including ridging and weeding technologies to reduce labour inputs, appropriate fertilizer application, identifying best intercropping practices; and (iii) organizing farmers to connect to the national collectors directly to reduce costs and time spent on individual marketing efforts.

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Medium 9781780644202

48; Building a Sustainable Sweetpotato Value Chain: Experience from the Rwanda Sweetpotato Super Foods Project

Low, J. CABI PDF

48 

Building a Sustainable Sweetpotato

Value Chain: Experience from the Rwanda

Sweetpotato Super Foods Project

J. Ndirigwe,1* K. Sindi,4 J. Low,2 D. Shumbusha,3 J.B. Shingiro,3

J.C. Nshimiyimana,4 S.Hakizimana5 and A. Angsten6

1

Rwanda Agriculture Board (RAB), Kigali, Rwanda; 2International

Potato Center Sub-Saharan Africa (CIP-SSA), Nairobi, Kenya;

3

RAB, Huye, Rwanda; 4International Potato Center (CIP), Kigali,

Rwanda; 5Catholic Relief Services, Kigali, Rwanda; 6Johns Hopkins

University, Baltimore, USA

Abstract

Sweetpotato is widely grown in almost all agroecological zones of Rwanda, where it is prized by most resource-poor farmers as a reliable, low-input, food security crop but with limited commercial potential. The bulkiness, lack of processing technologies and lack of market at the peak of sweetpotato production are reported as major constraints by producers and policy makers for scaling up production.

A strategy to promote and make available to farmers disease-free planting material of two elite selected orange-fleshed sweetpotato varieties (Gihingamukungu and Cacearpedo) that yield roots of acceptable consumer quality was initiated and has been adopted by organized farmers’ groups in three districts.

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10: New Elite Potato Clones with Heat Tolerance, Late Blight and Virus Resistance to Address Climate Change

Low, J. CABI PDF

10 

New Elite Potato Clones with

Heat Tolerance, Late Blight and Virus Resistance to Address

Climate Change

M. Gastelo,* L. Diaz, J.A. Landeo and M. Bonierbale

International Potato Center (CIP), Lima, Peru

Abstract

Potato production in developing countries is expanding to warmer environments as farmers search for income opportunities and food security. Meanwhile, climate change is already affecting weather

­patterns in traditional potato-growing areas, where unpredictable rains and pressure from pests and disease are increasing farmers’ risk. Since 2004, the International Potato Center (CIP) has sought to develop new, more heat-tolerant generations of its tropical highland-adapted late-blight resistant population. Late-blight resistant parents were crossed with early maturing and virus resistant progenitors, and selection practised under warm temperatures, water deficit and mid-latitude conditions.

During the 2005–2006 summer season (January–March) 20,000 genotypes were exposed to heat in a screenhouse at CIP’s experimental station in San Ramon, a warm rain forest environment at 800 m above sea level (masl) and latitude 11° 08¢ S. Selected clones were assessed in the field in the same location, where average night and day temperatures during tuberization were 21°C and 27°C, respectively; the resulting heat tolerant clones were exposed to high, endemic late blight pressure in Oxapampa

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