Sustainable potato production

SustainablepotatoproductionGUIDELINES FOR DEVELOPING COUNTRIES

During the International Year of the Potato, celebrated in 2008, FAO and CIP helped forge partnerships worldwide to address critical aspects of sustainable potato production. This technical guide collates that experience to review technical, socio-economic, policy and institutional factors that currently constrain increased potato production and productivity in tropical and subtropical countries. It presents Good Agriculture Practices relevant to potato production, and indicators and recommendations for action in key areas, from the utilization of potato biodiversity and improvements in seed systems, to soil management, insect pest and disease control and opportunities for value addition. It outlines a new policy and research agenda for the potato subsector that aims at making a real contribution to the eradication of hunger and poverty.

SustainablepotatoproductionGUIDELINES FOR DEVELOPING COUNTRIES

NeBambi LutaladioPlant Production and Protection DivisionFAO, Rome, Italy

Oscar OrtizIntegrated Crop Management DivisionInternational Potato CenterLima, Peru

Anton HaverkortWageningen University and Research CentreWageningen, The Netherlands

Daniel CaldizMcCain Foods LimitedBalcarce, Argentina

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS2009

ISBN 978-92-5-106409-2

The designations employed and the presentation of material in this information product do not implythe expression of any opinion whatsoever on the part of the Food and Agriculture Organization of theUnited Nations concerning the legal or development status of any country, territory, city or area or of itsauthorities, or concerning the delimitation of its frontiers or boundaries. The mention of specificcompanies or products of manufacturers, whether or not these have been patented, does not imply thatthese have been endorsed or recommended by FAO in preference to others of a similar nature that arenot mentioned.

All rights reserved. Reproduction and dissemination of material in this information product foreducational or other non-commercial purposes are authorized without any prior written permissionfrom the copyright holders provided the source is fully acknowledged. Reproduction of material in thisinformation product for resale or other commercial purposes is prohibited without written permissionof the copyright holders. Applications for such permission should be addressed to the Chief, ElectronicPublishing Policy and Support Branch, Communication Division, FAO, Viale delle Terme di Caracalla,00153 Rome, Italy or by e-mail to [email protected]

Cover illustration: Image elaboration from the photo Papa hallay, Peru by O.S. Butron Riossubmitted to the IYP World Photography Contest Focus on a global food.

© FAO 2009

Foreword 5Abbreviations and acronym 6Acknowledgements 7Introduction 9Section 1 Factors constraining the potato subsector 11

Technical factors 13Socio-economic factors 15Policy and institutional factors 17

Section 2 Good Agricultural Practices and potato production 19GAP concepts and principles 21GAPs in the potato subsector 23Production decision factors 25

Section 3 Key indicators of sustainability 31Biodiversity and varieties 33Seed production and seed quality 37Seed systems 43Soil health and fertility management 45Nutrient management 47Soil conservation 51Pest management 53Water management 57Post-harvest management 59Value addition and markets 63Farmers’ health, safety and welfare 65

Section 4 Implications for policy and research 67Building support at policy level 69Research for development agenda 71Partnerships for policy and research 75

Section 5 Potato fact sheets 77Potato and biodiversity 78Production of disease-free seed tubers 80Potato pest and disease management 82Potato and soil conservation 84Potato and water resources 86Potato and food price inflation 88

Bibliography 91

Contents

POTATO HARVESTIN TAMIL NADU,

SOUTHERN INDIA(PHOTO: JONATHAN

KINGSTON)

Celebrated in 2008, the United NationsInternational Year of the Potato (IYP)highlighted the important role of thepotato in agriculture, the economy

and world food security. IYP also had a verypractical aim: to promote the developmentof sustainable potato-based systems thatenhance the well-being of potato producersand consumers, especially in developingcountries.

This technical guide is a contribution toachievement of the International Year’sbroader development objective. Today, potatoproduction and consumption is boomingworldwide, with ever greater quantities beingprocessed for the convenience food andsnack industries, while its importance as asubsistence crop continues to expand. Manydeveloping countries wish to enter lucrativeemerging markets for potatoes and potatoproducts, but to do so need to make majorimprovements in the productivity,profitability and sustainability of theirpotato subsectors. For example, potato yieldsin the developing world average around 10to 15 tonnes per hectare, less than half ofaverage yields achieved by farmers inWestern Europe and North America.

The present guide builds on experiencegained through partnerships forged duringIYP implementation to address criticalaspects of sustainable potato production. Itrepresents the first inter-partner effort, post-2008, aimed at producing technicalguidelines that can be used by decisionmakers in developing countries to improvethe sustainability of potato production and

boost the potato subsector’s contribution tosocial and economic development.

The guide presents a summary review offactors that constrain the potato subsector intropical and subtropical countries, principlesof Good Agriculture Practices, and GAPsrelevant to potato production. It providesindicators and recommendations for actionin key areas – from the conservation andutilization of potato biodiversity andimprovements in seed systems, tomanagement of soil fertility, insect pest anddiseases, water use, the importance ofstorage, and the opportunities created byvalue addition. It also provides “snapshots”of selected best practices and examples ofsuccessful approaches in developingcountries. It concludes with a series of usefulfact sheets on key issues in potatodevelopment.

While aimed primarily at decisionmakers at institutional level, the guide willalso be of use to technicians, potato growersand processors. We trust that it will helpfurther IYP’s goal of helping to realize thepotato’s full potential as a “food of thefuture”.

5SUSTAINABLEPOTATOPRODUCTION

Foreword

Shivaji PandeyDirector, PlantProduction andProtection DivisionFood and AgricultureOrganization of the United Nations

Pamela AndersonDirector GeneralInternational PotatoCenter

Abbreviations and acronymsCIP International Potato CenterDLS Diffuse light storesFAO Food and Agriculture Organization of the United NationsGAP Good Agricultural PracticesFFS Farmers’ Field SchoolsICM Integrated Crop ManagementIDM Integrated Disease ManagementIPM Integrated Pest ManagementIPPM Integrated Potato Pest ManagementNGO Non-Governmental OrganizationsNSI Nutrient Supplementation IndexPMCA Participatory Market Chain ApproachPRSP Poverty Reduction Strategy Papers

Development of this guide wasinitiated as part of the InternationalYear of the Potato 2008, which wasfacilitated by FAO’s Plant Production

and Protection Division (AGP), inpartnership with the International PotatoCenter (CIP). The International Year helpedraise awareness of the potato subsector andsupport for its development, and served as acatalyst for the initiatives aimed atovercoming policy constraints to potatodevelopment.

This manual was conceived, initiated,guided and edited by NeBambi Lutaladioof AGP. He benefited from the collaborationof colleagues in partner institutions,in particular the International Potato Center(CIP), Wageningen University ResearchCenter (WUR) and McCain Foods Ltd ofCanada.

Special thanks for their technical inputsare due to Jean Pierre Anota and AmirKassam (consultants), to Anne SophiePoisot, Mike Robson, Tom Osborn, MichaelLarinde and Marjon Fredrix of AGP, and toAndreas Oswald, Carlo Carli, FernandoEzeta, Graham Thiele, Merideth Bonierbale,Roberto Quiroz and Victor Mares of CIP.

The contribution of Anton Haverkort ofWageningen University and ResearchCentre, Daniel Caldiz of McCain Foods Ltd,and Oscar Ortiz of CIP in reviewing andproviding constructive suggestions isgratefully acknowledged.

Eric A. KuenemanDeputy Director, Plant Productionand Protection DivisionFood and Agriculture Organizationof the United Nations 7

SUSTAINABLEPOTATOPRODUCTION

Acknowledgements

AT A POTATOSORTING FACTORY

IN THE NILE DELTA,EGYPT.

(PHOTO:MOSTAFA MOFTAH)

The potato is the world’s mostimportant root and tuber cropworldwide. It is grown in more than125 countries and consumed almost

daily by more than a billion people.Hundreds of millions of people indeveloping countries depend on potatoes fortheir survival. Potato cultivation isexpanding strongly in the developing world,where the potato’s ease of cultivation andnutritive content have made it a valuablefood security and cash crop for millions offarmers. Developing countries are now theworld’s biggest producers – and importers –of potatoes and potato products.

Once harvested, potatoes can be used fora variety of purposes: as a fresh vegetable forcooking at home, as raw material forprocessing into food products, foodingredients, starch and alcohol, as feed foranimals, and as seed tubers for growing thenext season’s crop.

Around the world, consumer demand isshifting from fresh tubers to processedproducts and ever greater quantities ofpotatoes are being processed to meet risingdemand for convenience food and snacks.The major drivers behind this trend includeexpanding urban populations, risingincomes, diversification of diets, andlifestyles that leave less time for preparingthe fresh product for consumption.

The development of a vibrant, profitableand sustainable potato subsector indeveloping countries depends on measuresto overcome a number of persistentconstraints. Those measures include

improvements in the quality of plantingmaterial, potato varieties that have reducedwater needs, greater resistance to insect pestsand diseases, and resilience in the face ofclimate changes, and farming systems thatmake more sustainable use of naturalresources. Not least, potato development –and agricultural development in general –requires empowerment of small farmersthrough improved access to productioninputs, credit and markets.

These guidelines present a compilationof potato management practices in use intropical and subtropical developingcountries that have helped increase potatoproduction and productivity. They can berefined to address particular conditions inspecific locations. The publication providesindicators of sustainability, and highlightspotential areas of improvement for potatodevelopment. While aimed primarily atdecision makers, the manual tries as muchas possible to use language familiar tofarmers.


Introduction

POTATO FIELDSIN CENTRAL JAVA,

INDONESIA.(PHOTO: HARJONO

DJOYOBISONO)

SECTION 1

Factorsconstrainingthe potatosubsector In the years ahead, world potatoproduction is expected to growat a rate of 2.5 per cent a year,presenting opportunities for expandedutilization and opening up newmarket segments. To realize the fullpotential of this crop, developingcountries must address both supply-and demand-side constraints.

POTATO MARKETIN KASUNGU, MALAWI.

(PHOTO: ANNE LI)

The potato’s biologicalcharacteristicsMany constraints derive from the biologicalcharacteristics of the potato itself. Theseinclude the low multiplication rates of seedtubers, and the technical difficulties andcosts associated with maintaining seedquality through successive multiplications,owing to the potato’s susceptibility to soiland seed-borne insect pests and diseases.Seed tubers are also bulky: two to threetonnes per hectare is the typical seedrequirement. Stringent phytosanitaryrestrictions limit the movement of potatogermplasm, seed tubers and fresh warepotatoes. Potatoes have high fertilizerrequirements but low utilization efficiency.Post-harvest, fresh potato tubers deterioratequickly in tropical and subtropicalenvironments, especially in the lowlands.

Lack of efficient seed systemsMany developing countries lack efficientsystems for the regular multiplication anddistribution of certified seed tubers and therapid deployment of new, improved varieties.Causal factors include the limited technicalcapacity of human resources, lack ofmanagerial expertise and inadequateresource allocations to seed systems and thepotato subsector in general. As a result,farmer-based seed systems are still common,and have managed to supply plantingmaterial of limited quality over the years,and contributed to expanding cultivation ofthe crop. Farmer seed systems face manychallenges, but also offer an opportunity to

improve seed supply, provided suitabletraining is available and links with theformal sector are established.

Diseases and insect pestsDiseases and insect pests are another majorconstraint. New strains of late blight havereached many developing countries andcontinue to spread. Late blight constitutesthe most serious threat to increased potatoproduction. Second to late blight inimportance, particularly in warmer, moretropical regions, is bacterial wilt. The impactof insect pests varies between regions. Majorinsect pests include aphids, tuber moths, leafminers, Colorado potato beetle and Andeanpotato weevil.

13FACTORSCONSTRAININGTHE POTATOSUBSECTOR

Technical factors


The US government’s AfricanGrowth and Opportunity Act(AGOA) provides preferentialaccess for more than 1,800 tariff

lines, including agriculturalcommodities, from designatedsub-Saharan African countries.The Everything But Arms (EBA)

initiative of the European Union(EU) eliminates import tariffsand restrictions on numerousgoods, including agriculturalproducts, from least developedcountries provided that planthealth regulations are met. EBAgrants duty-free access forimports from most LessDeveloped Countries, except fora few sensitive commodities(e.g. bananas, sugar and rice)that will be liberalized gradually.Most of the commoditiesincluded in EBA previouslyreceived duty-free access to theEU under preferentialprogrammes such as theLomé/Cotonou Agreement.

Export markets open in USA and Europe

LOCAL TRANSPORTATIONOF POTATOES TO MARKETIN MYANMAR.(PHOTO: ZIN MIN)

High production costsand lack of creditCompared to other food crops, production ofpotatoes is capital-intensive, requiring thepurchase of large quantities of bulky seedand the application of high-cost inputs suchas fertilizers and pesticides. With limitedaccess to credit and few means of mitigatingthe risks of taking out loans, small-scalefarmers find it difficult to compete in potatoproduction. The current global financialcrisis could leave a great number of farmerswith little money and no credit to invest inproduction.

Price instabilityWith potato becoming increasingly a cashcrop, small-scale potato growers arevulnerable to abrupt changes in input andoutput prices. Seasonal and year-to-yearprice movements can affect individual smallgrowers who lack the financial resourcesand resilience of larger producers andcooperatives.

Inefficiency of local marketsPotato prices are usually determined bysupply and demand, not the vagaries ofinternational markets as in the case ofcereals. It is, therefore, a crop that can helplow-income farmers and consumers to rideout episodes of food price inflation, such asthat experienced worldwide in 2007-08.However, the profitability of potato dependson efficient local markets and measures tocontrol overproduction.

Limited access to higher valuemarketsTo be successful, small-scale potato growersneed access to profitable emerging domesticmarkets – such as the rapidly growingprocessing segment – as well as to potatoexport markets. However, access to domesticmarkets is often restricted by the marketingpower of foreign suppliers, while exports areconstrained by trade barriers in developedcountries to processed products from thedeveloping world. However, there areencouraging “success stories” that illustratehow small-scale producers can increaseproduction and expand their market share.In India, potato growers who adapted newtechnology with the support of McCainFoods Ltd more than doubled their yieldsand incomes. Other private industries,including small businesses, have launchedpotato chips made from coloured nativepotatoes that were prototyped by CIP inorder to promote the sustainable use ofbiodiversity in the Andean Region. Recentlegislation in the USA and Europe providegreater access to agricultural products fromthe developing world.


Socio-economic factors


Neglect of the potato subsectorWith a few notable exceptions – such asEthiopia – most developing countries havepolicies toward the potato subsector, andespecially small-scale producers, that can bebest characterized as “benign neglect”. Littleor no public investment is targeted atintegrated strategies for crop improvement,value addition and marketing schemes orthe potato production-processing-marketingchain. Many countries lack adequate seedproduction systems backed by certificationand seed laws. Breeding rights are often notrespected, reducing incentives to breeders tocreate new adapted and resistant varieties. Inmany areas, poor infrastructural facilitiesand poor access to markets are also majorchallenges to expansion of potato productionand its profitability.

Inadequate capacity buildinginitiativesThe potato has attracted private sectorinvestment in the crucial area of seedmultiplication and seed systems in only afew countries. Support for programmes forthe diffusion of new varieties and for thescaling up of existing integrated disease andinsect pest management technologies andmethodologies is generally inadequate.Programmes to upgrade the skills of potatogrowers need to be matched by governmentefforts to create, monitor and enforceregulations on pesticide use and the spreadof pesticide or fertilizer residues into watersupplies, which are major constraints to thesustainability of potato production systems.

Lack of support to farmerorganizationsand entrepreneurs Support for potato farmer groups andassociations and for local entrepreneurshipis lacking in many countries. In Bangladeshand Pakistan, powerful lobbies represent themost serious obstacle to the development ofa local seed potato industry. One notableexception is Argentina, where efforts arebeing made by public and private sector toimprove seed quality and promote varietydevelopment, and to transfer technology forintegrated crop management to its contractgrowers.


Policy and institutional factors

POTATO PLOTS IN SRI LANKA.(PHOTO: ALEFIYA AKBARALLY)

SECTION 2

Good AgriculturalPractices andpotato productionThe term Good Agricultural Practices(GAPs) refers to principles and codesof practice that are applied to on-farmproduction and post-production processesand aim at ensuring safe and healthyfood and non-food agricultural products,while taking into account economical,social and environmental sustainability.


With most GAP applications,production costs are lower,losses reduced, and use of inputsrationalized as a bettermanagement system is put inplace. The cost of private GAPstandard certification (e.g. forGlobalGAP or Tesco Nature’sChoice) may be higher owing tostricter requirements. However,this does not necessarily have tobe the case with adoption ofgood practices per se. Generally,there is no higher cost to theconsumer – that is why retailersand commercial farming arerapidly adopting GAPs. Whereadoption of GAPs entailsadditional costs, the benefits ineconomic, social orenvironmental terms are usuallyhigher.

The cost of GAPs

SORTING OF POTATO IN INDIA.(PHOTO: RINI MAJUMDAR)

GAPs may be applied to a wide rangeof farming systems and at differentscales. They are applied throughsustainable agricultural methods,

such as integrated pest management,integrated water and fertilizer management,and conservation agriculture. GAPs arebased on four principles:1. to economically and efficiently produce

sufficient quantities of safe andnutritious food;

2. to sustain and enhance ;3. to maintain viable farming enterprises

and contribute to livelihoods;4. to meet the cultural and social needs of

society.

GAP applications are being developed bygovernments, NGOs and the private sector tomeet the needs of growers and processorsand for other specific purposes. They providethe opportunity to assess and decide onwhich to follow at each step of theproduction process.

It is important that GAPs are appliedin a coordinated way. For each agriculturalproduction system, GAPs should be part ofa comprehensive management strategy,providing for adjustments when needed inresponse to changing conditions. Theimplementation of such a managementstrategy requires knowledge, planning,measuring, monitoring and record-keepingat each step of the production process.Adoption of GAPs may sometimes result inhigher production, processing andmarketing costs, and higher prices for the

consumer. To minimize costs, whilemaintaining the quality and safety of foodproducts, participatory technical trainingand advice can be used to inform farmers ofnew technologies that will benefit them.

Information on options for GAP adoptionwould be facilitated through the use ofcommon databases and informationexchange platforms on available enablingtechnologies and integrated productiontechniques for different major agro-ecological areas.

21GOODAGRICULTURALPRATICESAND POTATOPRODUCTION

GAP concepts and principles


Soil management6 Reduce wind and water erosion through

hedging and ditching. 6 Apply fertilizers at appropriate moments in

adequate doses (e.g. based on soil analysis andcrop requirement) to avoid extra costs andpossible run-off and leaching.

6 Maintain or restore soil organic contentthrough application of manure, use of grazingand/or crop rotation .

6 Reduce soil compaction by avoiding use ofheavy machinery.

6 Maintain soil structure by limiting heavy andsometimes unnecessary tillage practices, andthrough use of cover crops such as pulses.

Water use efficiency6 Use minimum or zero-tillage and maintain soil

cover to reduce soil evaporation and improvesoil structure and water infiltration.

6 To avoid water loss by drainage, scheduleirrigation and monitor plant needs and soilwater reserve status.

6 Prevent soil salinization by matching waterinput to needs, allowing some drainage andrecycling water whenever possible.

6 Avoid excessive drainage and fertilizer run-off. 6 Maintain permanent soil cover in winter to

avoid nitrogen run-off and wind erosion thatcontributes to soil degradation.

6 Carefully manage the water table by limitingwithdrawals.

6 Avoid soil compaction (e.g., caused by toomany passes of farm machinery) which cancause water logging and lead to emergence ofpotato diseases during storage.

Examples of GAPs

Applied to the potato subsector,GAP principles imply that potatoproduction:

1. takes place in an economically efficientway;

2. contributes to food security by providingquantity and nutritional quality for abalanced food supply;

3. along with post-harvest handling andprocessing, ensures a safe food supply toconsumers;

4. conserves the natural resource base;

5. does not lead to emissions that endangerthe environment and biodiversity;

6. enhances potato biodiversity and ensuresa sufficient genetic base for varietaladaptation and resistance;

7. supports viable farming enterprises andcontributes to livelihoods;

8. meets the cultural and social needs ofsociety.

Several approaches can be utilized tooperationalize GAP principles in potatoproduction. The most stringent one attachescriteria to each principle, with indicatorsand indicator values. For example, thefollowing table summarizes criteria,indicators, indicator values and GAPs thatcould be used in implementing principle4 above:


GAPs in the potato subsector

Conserving the natural resource baseCriteria

conserve soilorganic matter

percentage ofsoil organicmatter

5% organicmatter

apply compost, manure or green manureto keep soil organic matter at the desiredlevel

avoid soilerosion

surface run-offof soil particles

0 kg soil loss persquare meter peryear

apply contour farming, make terracesand use minimum or zero-tillageimplements

ensurereplenishmentof groundwaterused byirrigation

depth of thewater table

5 m belowtopsoil level

do not over-irrigate from deep wells andtap other water sources or growpotatoes during a wetter period of theyear if the threat of disease is not high.

Indicators Indicator values GAPs


“PACHAMAMA HUELLA” LAND PREPARATION

FOR POTATO IN BOLIVIA.(PHOTO: MANUEL SEOANE

SALAZAR)

In potato-based systems in developingcountries, the GAP concept can beassociated with critical productiondecision factors and recommendations.

Environmentand production zonesThe potato is essentially a “cool weathercrop”, with temperature being the mainlimiting factor. In tropical areas, potatoshould be grown where the climate istempered by altitude (1 500 – 4 200 m) orat lower altitudes provided the crop is grownduring the cool season.

The ideal condition for tuberization is anight temperature of around 16°C, whileoptimum yields are obtained where meandaily temperatures are in the 18-20°C range.Loose, moist and well-drained slightly acidsoil (with pH of 5.0-5.5) or volcanic uplandsoils are preferred. The water supply for thepotato crop should be regular, especiallyfrom the stage of tuber initiation until theend of tuber enlargement.

Cultivation methodsA successful potato crop depends onjudicious cultural practices. These includegood knowledge of variety purity andcharacteristics such as dormancy duration,the physiological condition of seed potatotubers (well sprouted and 30-80 g in weight,depending on variety) and resistance to themain transmissible potato diseases andnematodes.

Potatoes are best grown in rotation. Inthe Andes, it is usually the first crop in the

rotation. In other regions, it can be plantedafter cereals and before legumes, but notwith crops (e.g. tomato and othersolanaceae) that are susceptible to the samepathogens as the potato. Sometimes naturalfallow is necessary to prevent soilimpoverishment and the build-up of potato-specific diseases and insect pests.

Soil preparation for the potato cropshould be adequate with minimum soildisturbance. Naturally loose soils, andloamy and sandy loam soils that are rich inorganic matter with good drainage andaeration, are the most suitable.

Planting depth, density and spacingdepend on the variety chosen and tuber size,and should allow for shallow inter-rowridging, when required. Usually, about twotonnes of seed tubers are planted perhectare.

To give the crop a competitive advantage,weeding should be performed after full cropemergence (about 4 weeks after planting)and after the plants have reached a height ofabout 20 cm. Shallow ridging is donesubsequently to prevent the stolonsbecoming aerials, and to protect tubersagainst insect pests, disease infection andgreening. Crop rotation and carefulchemical control with herbicides, applied atminimum lethal doses, may be part of anintegrated weed management system,although in most developing countries weedmanagement is usually carried outmanually.

A few basic precautions against insectpests and diseases can help avoid great yield


Production decision factors


POTATO HARVESTINGIN PANUTY DISTRICT,NEPAL.(PHOTO: G.M. BAKASH)

and quality losses. They include croprotation, use of resistant varieties andhealthy, certified seed tubers (if available orat least seed from a reputed source orthrough positive selection), and integrateddisease and insect pest management, whichinvolves regular monitoring of aphid andthrips vectors, other insects and naturalenemy populations, and chemical sprayingonly when necessary.

Fertilizer application during the stagesof pre-planting, planting or crop growthshould be determined by soil nutrientavailability, taking into account thepotato’s high demand for potassium,phosphorus and magnesium deficienciesin acid soils. The NPK ratio 1-1-1 is usuallya wise choice to avoid spoiling tuberquality. The potato can benefit from theapplication of organic manure at the startof a new rotation as it provides a goodnutrient balance and protects soil structurefrom compaction and erosion.

As soil moisture must be maintained at arelatively high level in production ofpotatoes, compared to other crops, irrigationmay be required where rainfall is limited.

HarvestingFor most commercial varieties, yellowing ofthe potato plant’s leaves and easy separationof tubers from stolons indicate that thepotato crop has reached maturity. If thepotatoes are to be stored rather thanconsumed immediately, they are left in thesoil to allow their skin to harden – hard skinalso help seed potatoes to resist storagediseases. However, leaving tubers for toolong in the ground increases their exposureto the fungal disease black scurf andincreases the risk of losing quality andmarketable yield.

To facilitate harvesting and stop tubergrowth, potato vines should be removed twoweeks before the potatoes are dug up.Depending on the scale of the production,potatoes are harvested using a spading fork,a plough or commercial potato harvestersthat unearth the plant and shake or blowthe soil from the tubers. During harvesting,especially if it is done mechanically, it isimportant to avoid bruising or otherinjuries, which provide entry points forstorage diseases and reduce the commercial,processing quality and storability of thetubers.

In suitable environments and wheregrowing conditions are adequate,commercial yields are in the range of 40–60tonnes per hectare. In many developingcountries, however, they are far below thisfigure, with national averages of about 10-20 tonnes per hectare.



Storage and transportIn the tropics and where refrigerated storageis not available, seed tubers should be storedunder diffuse light in order to maintaintheir sprouting capacity and to encouragedevelopment of vigorous sprouts. In regionswith only one cropping season per year andwhere storage of tubers from one season tothe next is difficult without the use of costlyrefrigeration equipment, off-season plantingmay offer a solution. Importation of seedtubers is common in these regions, but mayentail higher costs and risks of late deliveryand deterioration in tuber quality along themarketing chain.

Ware potatoes should be kept at atemperature of about 6 to 8°C, in a dark,well ventilated environment with high

relative humidity (85 to 90 percent). Forprocessing purposes, such as the productionof french fries, storage temperatures mayrange up to 10°C to reduce the risk ofincreasing sugar levels, which areresponsible for a dark colour during frying.Potato darkening can also be caused by anexcess of nitrogen in the fertilizationformula.

During transport of seed tubers and wareand processing potatoes, it is important toavoid bruising by reducing drop height,lining containers with rubber or other softmaterial, and avoiding extremetemperatures. Tubers should be protectedagainst unexpected rainfall and snow, whichcan occur at high altitudes.


PAPA,ALIMENTO

DEL PUEBLO,CUBA.

(PHOTO:YANDER ALBERTO

ZAMORADE LOS REYES)

SECTION 3

Key indicatorsof sustainabilityEleven indicators of sustainabilityhave been identified, each with specific GoodAgricultural Practicesand potential areas of improvement.


The 12 000 hectare Potato Parklocated in the Andes near Cuscois one of the few conservationinitiatives in which localcommunities are managing andprotecting their potato geneticresources and traditionalknowledge of cultivation, plantprotection and breeding. CIP hasrepatriated to the park hundredsof virus-free varieties of nativepotatoes which are now in fullproduction and yielding 30percent more than potatoes thathave not been cleaned ofviruses. The Potato Park helpspreserve indigenous knowledgeand ancient technologies, while

ensuring that the production ofnative varieties remains underlocal control. The approach couldserve as a model for otherindigenous communities

because biological diversity isbest rooted in its naturalenvironment and managed byindigenous peoples who know itbest.

A potato park in the Andes PAPA HALLAY, PERU (PHOTO: O.S. BUTRON RIOS)

The potato has the richest geneticdiversity of any cultivated plant.Potato genetic resources in SouthAmerican include wild relatives, native

cultivar groups, local farmer-developedvarieties (“landraces”), and hybrids ofcultivated and wild plants. These varietiescontain a wealth of valuable traits, such asresistance to insect pests and diseases,nutrition value, taste and adaptation toextreme climatic conditions. To controlinsect pests and diseases, increase yield andsustain production, especially on marginallands, today’s potato-based agriculturalsystems need a continuous supply of new,improved varieties, a process that requiresaccess to the entire potato gene pool.

Also at national level in regions outsidethe Andes, maintenance of and increase inthe genetic variability of available potatovarieties are needed in order to ensure thereis a sufficient broad genetic base foradaptation of the plant to localenvironmental conditions, such astemperature, day-length, moistureavailability, and insect pest and diseasepressures.

Crop genetic diversity3Facilitate efforts to conserve and

sustainably use potato germplasm.3Support breeding programmes and ensure

conservation of breeding stocks.3Breed varieties with high yield, high

nutritional value, resistance to maindiseases and high adaptability to less-favoured conditions.

Choice of potato variety3Promote varieties adapted to the range of

existing climatic conditions to ensure wideadaptability and stable production.3Abandon varieties with poor storage

characteristics and low levels of resistanceto major diseases.3Promote varieties that are already grown

in the country and are accepted by farmersand markets. 3Support participatory evaluation of

candidate varieties from breedingprogrammes and other countries for localtesting and release.

Good practices

33KEY INDICATORSOFSUSTAINABILITY

Biodiversity and varieties

34SUSTAINABLEPOTATOPRODUCTION FROM THE ESSAY,

“HARVEST OFNATIVE POTATOES,PERU.”(PHOTO:EITAN ABRAMOVICHSAMESAS)

3More effective national potato breedingprogrammes.3Adaptation of breeding objectives and

targets based on local expected results andneeds.3Focus breeding programmes on achieving

long term benefits, including not onlyresistance to insect pests and diseases butalso high, stable yield, greater resource-use efficiency, nutritional quality, andgood storability.

Potential areas of improvement3Disseminate complementary conservation

methods, especially the conservation ofbiodiversity carried out by farmers (insitu/on-farm conservation).3Reinforce “potato park” initiatives

through repatriation of biological diversityto farmers’ communities.



TAKING TIMETO CLEAN HARVESTED

POTATOES,THE PHILIPPINES.

(PHOTO: ARTEMIO LAYNO)

Areliable supply of good quality seedis crucial to the development of thepotato subsector. Availability of seedremains one of the main

constraints to the large scale adoption ofresearch-bred or research-derived improvedvarieties.

Good quality seed is essential to highyields and is usually the most costly input topotato cultivation, accounting for 30-50percent of production costs. Theimprovement of seed quality will contributeto enhancing farmer efficiency andcompetitiveness. The most important seedquality characteristics are variety purity,physiological stage, seed size, seed healthand physical aspect.

Seed production3Supply seeds that meet strict quantity,

timing, and quality-control requirements. 3Grow seed in the best and coolest areas or

time of the year in order to avoid insectpopulations that can transmit diseases.3Where potatoes can be grown year-round,

encourage farmers in a seed productionarea to include a “potato-free” period inthe farming calendar in order to breakcycles of insects that act as vector for virusdiseases.

Purity of varietyThe use of varieties with better quality andgreater adaptability to marginalenvironments will help to enhance potato

Good practices

production and ensure the sustainabilityand competitiveness of potato-basedfarming and utilization systems.3Seed should be of the same variety as that

by which it is sold.3Use varieties that are adapted and stable in

term of yields.

Where appropriate and where farmerscurrently use mixes of different varieties,ensure the added benefits of such mixturesin terms of tolerance to diseases and ensurethat farmers have adequate knowledge,infrastructure and guidelines to apply bestpractices for seed production.

Physiological stagePhysiological development of a seed tuber iscategorized as follows: 3Phase I = dormant period; 3Phase II=apical sprouting; 3Phase III=period of normal sprouting; 3Phase IV=period of thin sprouts;3Phase V= incubated – too old seed tubers.

As the physiology of the seed is a majorfactor in seed quality, storage systems andstorage duration are critical aspects to beconsidered. To obtain a high yielding crop,seed should be at the correct physiologicalage and sprouting stage at planting,depending on the purpose of the crop. Inprinciple, seed should be at least threemonths old before it is planted, and no olderthan 5-11 months (depending on variety,storage system and temperature).


Seed production and seed quality


POTATOHARVESTING

IN NEPAL.(PHOTO:

G.M. BAKASH)

3Provide a storage area with good aircirculation and adjustable lighting.3Store only seed tubers taken from healthy

plants and ensure they are devoid ofstorage diseases such as late blight,bacterial rot and silver scurf.3About one month before planting, pre-

sprouting of seed potatoes should favourquick emergence at planting time.3In the tropics, if no refrigerated storage

capacity is available, store seed potatoesunder diffuse light in order to maintaintheir sprouting capacity (i.e. help tubersstay physiologically young for longer) andto encourage development of vigoroussprouts.

Direct sunlight on potato seed should beavoided. Therefore: 3For long-term storage, store seed potatoes

either at 2-4°C or, when stored at highertemperatures, in diffused light.3The period between planting and

emergence should be kept as short aspossible in order to make best use of theavailable growing season. Therefore, atplanting time the seed should be at aphysiological stage that allows a quickemergence.3For planting, the best stage is phase III

(robust sprouts having their typicalvarietal colour), the “normal multi-sprouting” phase. 3Put bulked seed potatoes in trays to

stimulate more uniform sprouting.

Seed size3Use seed of uniform size, ranging from 25

to 50 mm or weighing between 30 to 80 g,depending on tuber size and shape.3Plant tubers which have little variation in

size. Using seed with a wide variation insize will not produce a uniform crop andmakes it more difficult to predict theplant density and properly manage thecrop.3Use large tuber seed when soil and weather

conditions at planting are unfavourable,the growing season is short, or where thereis the risk that during the first part of thegrowing season, the crop may be damagedby night frost, hail or drought.3Large tubers may be cut into smaller

pieces for planting to reduce seed costs andfavour a more uniform crop. This shouldbe done at least two weeks before plantingin temperature conditions of between 10and 22°C to allow wound healing prior toplanting. However, precautions are neededto avoid transmission of viruses via thecutting blades.

Seed health Seed potato is generally the main source ofinsect pest and disease infection, becausemost seed-borne diseases are systemic, thusfavouring disease transmission to the nexttuber generation. Seed treatment withchemicals can never replace the use of highquality seed or proper handling, storage andsprouting. Therefore:3Use only disease-free seed.3Produce seed tubers in disease-free areas



FROMTHE PHOTO ESSAY,

“BELARUS SOLDIERSEAT POTATOES.”

(PHOTO:VIKTOR DRACHEV)

and on land not infested with soil-bornediseases or insect pests.3Ensure proper sanitation by using clean

tools when cutting seed to avoid diseasestransmitted mechanically.3Practice crop rotation and remove potato

volunteers when cultivation and weedingare implemented.3Adopt strict rotation procedures, and never

use the same field more than once in a 3-4 year period.3Rogue out diseased plants, including

tubers, stolons and roots, being carefulto avoid spilling soil on healthyplants, and bury them in a pit outsidethe field.3In the tropics, use storage areas with good

air circulation and adjustable lighting.

3Disinfect storage structures every year byspreading lime (use of dangerouschemicals such as formalin is notnecessary).3Clear away potato residues, sacks and

other waste, as these can be breedinggrounds for potato tuber moths anddiseases.3Remove and destroy seed tubers infected

by diseases or insect pests during storage.3Make routine observations to identify

insect pest- and disease-infected tubers instorage.3Routinely control the temperature in the

potato heap (bulk) to ensure that norotting occurs. Rot processes are likely toemerge when bulk temperature suddenlyincreases. 41

KEY INDICATORSOFSUSTAINABILITY


In tropical areas such as theCentral African highlands, wherecold storage is unavailable or toocostly, smallholder growers storetheir seeds on the farm. Theefficiency of their simple homestorage facilities could bedramatically improved with useof diffuse light technology.Diffuse light stores (DLS) aremost suitable wheretemperatures are moderate (nofrost or extreme hightemperatures) and seed has to be

stored for more than fourmonths. By using DLS, farmersare able to store their own seedstocks, instead of buying themfrom distant suppliers. However,the loading capacity of DLS islimited since all tubers must beexposed to the diffuse light.These stores are suitablegenerally for small seed unitsand not for large scale seedproduction schemes. Seedpotatoes stored in diffuse lightgive a more vigorous crop than

seed that has been stored forrelatively long periods in the darkat higher temperatures.However, the DLS must beprotected against aphids (e.g.with an aphid proof screen) toavoid the risk of infection andtransmission of viruses such aspotato virus Y and potato leaf rollvirus. Since the aphid populationincreases throughout the storagephase, stringent controlmeasures need to be put in placeto reduce seed degeneration.

A technique known as “positiveselection” was pilot-tested bysmallholder potato farmers in theNarok district of Kenya as a wayof improving the quality of theirseed potatoes. Positive selectioninvolves marking healthy-lookingmother plants for later seedcollection. More than 100extension workers and farmer-trainers were trained in allaspects of positive selection, andthen assigned to work with some1 200 farmers organized in 70farmer groups. A participatory

research approach was used, witha demonstration experimentforming the core of the trainingcurriculum. All activities tookplace in the potato field, and themode of teaching was “learningby doing”. The farmer groups metregularly, learning first how todistinguish between sick andhealthy-looking plants in thepotato field. Next, a comparativestudy divided the potato fieldwas into two parts: one wherepositive selection was used andone where the farmers used their

traditional methods. Tubers fromthe two different selectionmethods were plantedseparately the next season, andthe group analysed the results.Within the positive selectionfield, potato yields increased onaverage by about 30 percent. Asurvey two years afterwardsshowed that more than onequarter of the farmers trainedhad adopted the positiveselection method. These farmersreported that their yields haddoubled.

Capacity-building for seed potato selection

Diffuse light storage for seed potato tubers

In most developing countries, the vastmajority of smallholder farmers usefarm-saved seed potato obtained fromnon-specialized seed growers, owing to

the lack of commercial seed productionsystems or, where they exist, to the high priceof certified seed. Farmer-based informal seedsystems are generally unable to maintainseed quality or eliminate diseases such asbacterial wilt or viruses. Poor functioningseed systems are consistently ranked by CIPas being among the major constraints toimproved potato production.

3Train seed growers in seed qualitymaintenance and managing bacterial wiltand viruses. 3In order to avoid multiplying different

categories of seed in the same locality andto sustain the replenishment of qualityplanting stock, promote a permanent“flush-out” system that preventsmultiplication of lower categories of seed.

Much effort has been made in the past toimprove seed potato production indeveloping countries, usually throughspecialized seed companies. However,commercially produced seed potatoesremain beyond the reach of manysmallholder producers, especially in sub-Saharan Africa, where producers rely onfarm-saved seed. Simple, low-cost

Good practices

Potential areas of improvement

technologies are therefore needed to helpdeveloping countries produce and distributethe healthy and high quality seed tubersneeded for sustainable and profitable potatoproduction.3Develop participatory research and

promote appropriate technologies toimprove the quality of farm-saved seed insub-Saharan Africa and other parts of theworld.3Identify localities with low vector pressure

and communicate the value of positiveand/or negative selection (rouging)practice for the production of potato seed3Determine the degeneration rate of seed

potatoes, by variety and location, so as todetermine how much basic seed needs tobe produced annually.3Introduce laboratories for disease

diagnostics to identify seed-borne viruses,bacteria and fungi. 3Introduce rapid multiplication techniques

and encourage small enterprises toproduce healthy material. 3Develop new methods to ensure the

production and delivery of high qualitypotato planting material and improveformal and farmer-based seed systems.3Develop legislation and accreditation

systems for seed certification adapted tolocal conditions.


Seed systems


FROMTHE PHOTO ESSAY,

“BELARUS SOLDIERSEAT POTATOES.”

(PHOTO:VIKTOR DRACHEV)

Maintaining a high yieldingpotential in potatoes requires soilhealth and fertility management.Soil health depends on physical

and chemical properties and functions,organic matter and biological activity, whichare fundamental to sustaining agriculturalproduction and determine, in theircomplexity, soil fertility and productivity.

Crop fertilization requirements need to becorrectly estimated according to the expectedyield, the potential of the variety planted andthe intended use of the harvested crop. Beforeapplication of fertilizers, farmers shouldperform, where possible, a soil test to identifysoil characteristics, nutrient content and soilcontaminants. Soil tests help assess fertilityand indicate deficiencies that need to beaddressed.

Potato should be planted with organicfertilizer, such as farmyard manure wherepossible and as appropriate. As well assupplying nutrients to the crop, organicfertilizer often increases the efficiency ofinorganic fertilizers, improving crop yieldssubstantially, and also improving soilhealth, which could have a positive effect byhelping to reduce soil borne diseases.

Farmyard manure3Of all field crops, potato has the best

response to farmyard manure. Use well-decomposed farmyard manure at a rate of10 tonnes per hectare or more, if available.

Good practices

3Precautions should be taken to reducenitrogen applications by 30 percent, ifinorganic fertilizers are applied at thesame time.3Avoid using fresh, incompletely

decomposed manure because it willbecome active too late in the season andmay reduce dry matter content, delaymaturity and transmit diseases (e.g.Rhizoctonia solani).

Fertilizers3Prior to planting, make a planting bed

with some 20 cm of loose soil mixed withfertilizer and/or manure to allow properrooting and hilling.3In moist soil, apply fertilizers at the root

zone (25-28 cm) where they are mosteffective.3To be more effective, place phosphates in

the root area because, unlike nitrogen andto some extent potassium, phosphateshave limited movement in the soil andwithin plants.3Use of fertilizers is advantageous when

levels of soil fertility are low.

3Promote conservation agricultureapproaches to soil health and fertilitymanagement.3Support integrated crop, soil health and

fertility management programmes.3Conduct research and development based

on adequate use and conservation ofnatural resources.



Soil health and fertility management


Sustainable nutrient managementinvolves a set of managementpractices designed to conserve soilresources, maintain or enhance

productivity, and help reduce growers’reliance on chemical fertilizers. Due to itsrelatively poorly developed and shallow rootsystem, the potato demands a high level ofsoil nutrients. Without balanced fertilizationmanagement, growth and development ofthe crop are poor and both yield and qualityof tubers are diminished.

The type and extent of nutrientmanagement depends on the productionpotential of the area in which potatoes arecultivated and farmers’ productivityobjectives. Farmers should be advised toperform a soil test before application offertilizers – fertilization is highlydependent on location and blanketrecommendations are not applicable. Theyshould also be aware of the effect of the soilpH on nutrient supply and the type offertilizer to be used.

Crop response to fertilizers varies from fieldto field. The fertilizer ratio of N-P-K oftenrecommended and practiced is usually 1:1:1.However, high yields and enhanced qualityof tubers can only be sustained through theapplication of optimal nutrient doses inbalanced proportions.

Nitrogen. The amount of nitrogen appliedto a potato crop varies from 100 to as much

Good practices

as 300 kg/ha depending on the purpose ofthe crop and soil characteristics.3Avoid high or excessive nitrogen dressing

as it stimulates haulm growth, delaystuber formation and affects tuber quality(low dry matter content, high reducingsugar content and high protein andnitrate content).3Apply nitrogen shortly before, or at,

planting time. However, if there is a risk ofleaching (e.g. with heavy watering on lightsoils), or if the application of largequantities of fertilizer under dry conditionsmay cause scorching, a split applicationmay be better. The second nitrogenapplication should, in general, be given nolater than three to five weeks after cropemergence.

Phosphorus. Phosphorus contributes to theearly development of the crop and earlytuberization. It increases the crop’s drymatter content and improves the tuber’sstorage quality. Often more than 100 kg/ hais applied, while on phosphorus-fixing soilsmuch higher doses are used.3Apply the total amount of phosphorus

before or during planting.3Apply phosphorus in the planting furrow

in P-fixing soils.

Potassium. Potassium not onlyimproves yields but also improves tuberquality (size, starch content and storability).An adequate supply of potassium canhelp reduce internal blackening andmechanical damage, and has been


Nutrient management


HARVESTEDPOTATOES BEING

LOADED INTO CRATES.(PHOTO: PASCAL BASTIEN)

associated with increased stresstolerance. 3Apply the total amount of potassium

before or during planting.

Magnesium

3Close attention should be paid tomagnesium requirements, particularlywhen potatoes are grown on light acidsoils. High rates of potassium, andnitrogen application in the form ofammonium, reduce the uptake ofmagnesium.

Calcium

3Potatoes are tolerant to soil acidity. BelowpH 4.8, however, the crop may fail due tocalcium deficiency. Liming may benecessary.3Seed potatoes, in particular, need to be

grown in soils with sufficient calcium.Calcium deficient seed tubers may fail tosprout properly.

Foliar fertilizers

3Foliar fertilizers contain major nutrientsand also micronutrients. They are appliedto and absorbed by the leaves and havetherefore an immediate effect on plantgrowth. They may help to overcomeapparent nutrient deficiencies, especiallyof micronutrients, and support plantrecovery following stress events, such asfrost and drought.

3Promote the establishment of laboratorieswhere soil mineral content can be assessedprior to planting. Laboratories can alsoverify the claimed concentrations of N-P-Kin commercial products.3Promote the development and use of

decision support systems that help growersapply fertilizers according to soil mineralcontent and crop needs.3Encourage fertilizer companies to market

compound fertilizers with compositions ofN, P and K tailored to different soil types.3Support integrated crop management

(ICM) programmes and integratednutrient management systems for potatoes.3For the fertilization of crop mixtures that

include potato, the Nutrient Supplementa -tion Index (NSI) concept can help estimatethe additional percentage of N, P, K and Caneeded to satisfy the needs of a 1:1 rowintercrop (e.g. potato-corn). NSI estimatestotal fertility input needs for the multiplecropping system based on the nutrientuptake of each crop component relative totheir monoculture uptake. With NSI,intercrop fertilizer needs can be estimatedfrom established sole crop response curvesfor the component species. Alternatively,fertilizer needs for the multiple crop systemcan be estimated for a given plantingpattern using the response equations ofone or more of the component crops.3Develop nutrient management practices

for potato production under conservationagriculture.




Conservation agriculture (CA)aims at enhancing naturalbiological processes both aboveand below ground. It is based onthree principles: minimummechanical soil disturbance,permanent organic soil cover,and diversified crop rotations forannual crops and plantassociations for perennial crops.By minimizing soil disturbance,CA creates a vertical macro-porestructure in the soil, whichfacilitates the infiltration ofexcess rainwater into the subsoil,improves the aeration of deepersoil layers, and facilitates rootpenetration.

The advantages of conservation agriculture

POTATO FARMING IN ARGENTINA.(PHOTO: H.C. CUEVAS)

Soil erosion on tillage-based cultivatedlands is a problem that continues tothreaten the sustainability of bothsubsistence and commercial

agriculture in potato growing areas aroundthe world. Potato cultivation usuallyinvolves intensive soil tillage throughout thecropping period, which often leads to soildegradation, erosion and leaching ofnitrates. During soil preparation, the entiretopsoil is loosened and – particularly onsticky clay soils – pulverized into smallaggregates to avoid the formation of clods inthe potato beds. Mechanical weeding andmechanized harvesting also entail intensivesoil disturbance.

The use of mulch at planting and the “no-till” land preparation method arerecommended to reduce soil degradation,erosion and nitrate pollution and to restoredegraded soils and achieve good potatoyields with reduced need for fertilizer. Themulch protects the soil from erosion duringthe first weeks of the crop.

A green manure crop can be seededtowards the end of the crop, as the potatoplants are drying off. The cover crop willhelp to dry out the potato beds, contributingto healthier tubers with reduced risk ofdamage during harvest. Nevertheless, whilemulch planting of potatoes reduces the riskof erosion and nitrate leaching, it may havesome disadvantages (e.g. excessive moistureand reduced soil temperature leading to

Good practices

retarded plant emergence). Hence it shouldnot be a blanket recommendation.

The “no-till” potato is pressed into thesoil surface, and then covered with a thicklayer of mulch, preferably straw, which isfairly stable and does not rot quickly. Theyoung potato tubers form under the mulchbut above the soil surface. In some cases –for example in dry areas under dripirrigation – black plastic sheets can also beused as mulch. Holes are punched in theplastic to allow the potato plant to growthrough it. During harvesting, the sheets areremoved and the potatoes are simply“collected”. Currently, the “no-till” potato isonly grown in small fields using manuallabour.

3Promote conservation agricultureapproaches as a resource-saving cropproduction system.

Potential areas of improvement 51KEY INDICATORSOFSUSTAINABILITY

Soil conservation


Incorporation of the followingpractices into the productionscheme should result in optimalhealth of the potato crop:6 Plant healthy seed tubers

from reliable sources. 6 Select and prepare planting

site, and choose cultivars,planting and harvest dateswith disease and insect pestmanagement in mind.

6 Handle and plant seedpotatoes to ensure rapidemergence, and protectfoliage using a holistic cropprotection approach orintegrated production andpest management.

6 Minimize tuber infection bytimely killing or removal ofvines before harvest; avoidtuber injury and cure tubersbefore long term storage.

6 Manage storage conditionsto minimize post-harvestdeterioration.

Principles of potato plant health management

POTATO PLANT(CIP)

Potato diseases are spread by insectvectors, seed and wind, runningwater, soil, sacks and implements.Seed is generally the main source

of infection. Combating insect pests,diseases and weeds with intensive useof insecticides, fungicides and herbicidescan harm the environment and pose aserious threat to the health of producersand consumers.

Regular field monitoring for pestsand the broader agro-ecosystem is thebasis for ecological-based plant protectionand pest management. For example,aphid monitoring and consequentadjustment of planting and harvest dateswould deserve special attention as a feasibleknowledge-based practice in the context ofinsect pest management. However, themanagement of potato late blightis difficult without fungicides. Therefore,the use of biocides is acceptable, and oftenconsidered as a component of integratedinsect pest and disease managementschemes.

3To increase potato production whileprotecting producers, consumers and theenvironment, use insect pest and diseasemanagement strategies that encouragebiological control of insect pests, varietieswith insect pest and/or disease resistance,planting of healthy seed potatoes, thegrowing of potatoes in rotation with othercrops, and organic composting to improvesoil quality.3Whenever possible, use rotations that

reduce insect pest and disease problemsand avoid those that may increase them.In general, avoid solanaceous crops asrotation choices.3Control volunteer potato plants and weeds

in the rotation crop.3Avoid build up of weed seeds in the soil by

removing weeds before they flower and setseeds.3Reduce or eliminate weed seeds in soil

through conservation agricultureapproaches to weed management.

Good practices


Pest management

In developing countries, farmersgenerally lack knowledge of lateblight (LB) control measures, andhave limited or no access toresistant varieties andagricultural inputs needed tocontrol potato LB effectively. CIPis working on different fronts todevelop alternatives to controlLB. In recent decades, itsbreeding programme hasdeveloped LB-resistant varietiesadapted to smallholder farmingconditions in tropical

environments. Some of thesevarieties are already beingcultivated in several countries inLatin America (Bolivia, Colombia,Ecuador, Peru), in Africa (Ethiopia,Uganda, Rwanda, Tanzania) andin Asia (China, India). CIP has alsodeveloped technical principles foroptimizing fungicide use, and fordesigning and adaptingparticipatory research andtraining methods to deal with thecomplexities of LB management.The experience in LB

management accumulated so farhas shown that returns oninvestment in controlling thedisease are high, with marginalrates of return ranging from 260percent to 1360 percent. Theseare especially significant forresource-poor farmers for whompotato cultivation represents animportant coping strategy.Support is needed to helpoptimize this impact by scalingup and out the technologies andmethodologies developed by CIP.


Improper use of pesticides inpotato cultivation is a majorenvironmental concern. Themost widespread and intensiveuse of pesticides in developingcountries is for control of lateblight (LB) potato disease.Farmers in some countries spraytheir potato fields more than 10times during a single growingseason of 4 to 6 months tocombat this disease. Biocides area health risk to farm families andfarm workers engaged in potato

production. With the emergenceof new and more virulent strainsof LB, even more frequent (andincreasingly ineffective)applications of pesticides arebeing made, raising the risk tohuman health and theenvironment. The spread ofpesticides or fertilizer residuesinto water supplies throughirrigation systems or field run-off contribute to water pollutionthat damages plants, insects andlivestock, and poses a serious

threat to drinking water and towater used for post-harvestactivities. Concern overenvironmental and healthimpacts, combined with thebetter appreciation of thedamage different diseases andinsects cause to the potato, haveled to the development anddiffusion of alternativetechnologies including disease-resistant varieties and integratedmanagement (IDM/IPM)techniques.

Fighting potato late blight

Pesticides and the environment

3Develop approaches that are specific to thetarget pests and have the least harmfuleffect on other organisms, human healthor the environment.3Develop decision support systems that

assess disease or insect pest pressure andidentify the most appropriate timing anddosage of chemical interventions.3Ensure that when there is a need to apply

pesticides, appropriate equipment is usedand measures are taken to reduce risksduring handling of the pesticides.3Establish laboratories to verify compounds

and concentration of the activeingredients in pesticides.

Potential areas of improvement3Support facilitation of CIP’s integrated

pest/disease management (IPM/IDM)programme, FAO’s IPM and any otherIPPM approach through Farmer FieldSchools or other formal or informalextension programmes.3Always aim for reduced use of pesticides by

applying IPM practices. If pesticides mustbe applied, use only products registered inthe country, give preference tocomparatively less toxic pesticides strictlyfollow usage recommendations andensure that farmers and farm workers useproperly functioning protectiveequipment.3Promote conservation agriculture

approaches to crop health management.



AN IRRIGATED POTATOFIELD IN CAPE VERDE.

(PHOTO: MARZIO MARZOT)

In potato production, shortages of waterare usually one of the most importantconstraints to higher yields. Achievingbetter yields requires an adequate water

supply from planting until maturity. Themain effect of drought or water stress onpotato is yield and size reduction.

Frequent irrigation reduces theoccurrence of tuber malformation. For thepotato, the critical period for water deficit isduring tuber development. Water deficit inthe early phase of yield formation increasesthe occurrence of spindled tubers (morenoticeable in oval than in round tubervarieties) and, when followed by irrigation,may result in tuber cracking or tubers with“hollow hearts”. Therefore, water supply andscheduling have important impacts onpotato growth, yield and tuber quality.

3Match water application to the potatocrop’s water requirements and maintainadequate soil moisture to maximize yield.For best yields, a 120 to 150 day croprequires from 500 to 700 mm (20 to 27.5inches) of water. 3Avoid water deficits in the middle to late

part of the growing period – deficitsduring stolonization, tuber initiation andbulking tend to reduce yield.3Allow higher depletion toward the ripening

period (a practice that may also hastenmaturity and increase dry matter content).

Good practices

3Where water supply is limited and salinitymight become a problem, use of atechnique known as “partial root-zonedrying” increases water use efficiency.Potatoes are planted in furrows so that oneside can be irrigated and the other kept dryin one watering cycle; the opposite furrowsare watered in the following cycle.3Use no-till and soil cover to minimize soil

evaporation.

3Support research aiming at developingdrought tolerant and resistant varieties.3Improve irrigation and fertilization

techniques using conservation agricultureapproaches.



Water management


Since harvested tubers are livingtissues and therefore subject todeterioration, proper storage isessential, both to prevent post-harvest

losses of potatoes destined for freshconsumption or processing, and toguarantee an adequate supply of seed tubers.The storage of potatoes is intended: • to preserve them in first class condition for

consumption by the grower and customers;• to add value and increase profit through

off-season sales or during the morelucrative high-price season;

• to preserve tubers for planting in the nextseason.

For ware and processing potatoes, storageaims at preventing “greening” and losses inweight and quality. In potato storage, thetwo critical environmental factors aretemperature and humidity. Adequate andunrestricted air movement is necessary tomaintain constant temperature andhumidity throughout the storage pile, and toprevent excessive shrinkage from moistureloss and decay. The storage temperatureaffects curing and wound healing processes,the spread and severity of disease, sugar-starch balances, and respiration.Respiration, in turn, influences dormancy orsprouting, and weight loss. High humidity isessential for optimum wound healingduring the curing period.

It is also essential throughout the storageperiod in order to minimize tuber weightloss – weight loss rapidly increases atrelative humidity levels below 90 percent.

Depending on variety and conditions duringgrowth, at 10-13°C and 93 percenthumidity, potatoes store for 1-3 months; at8-10°Cand 93 percent humidity for 2-5 months;at 5-8°C and 93 percent for 4-8 months;at 2-5°C and 93 percent humidity for 7 months.

3Store well cured potatoes that wereharvested when ripe (2 weeks after foliagedeath) in a well-ventilated, dark, coolplace at about 4°C (where refrigeration is an option) with humidity around 90 percent. The potatoes will store forroughly three to six months.3Store only tubers that are mature and free

of diseases, insect pest and physicaldamage such as bruising. Research hasdemonstrated that potatoes from healthyplants are much more resistant to storagedecay than potatoes from plants that havebeen weakened from physiologicalstresses.3Handle the tubers carefully throughout the

harvesting and pre-storage operations inorder to minimize bruising, skinning andcutting. Ideally, the harvest should becarried out in temperatures of between 10-18°C. Do not harvest when tuber pulptemperature is less than 8°C or morethan 20°C.3Remove soil and plant residues before

placing potatoes in storage.3A wound healing or curing period is

Good practices


Post-harvest management


COLLECTINGPOTATOES

IN DIENG PLATEAU,INDONESIA.

(PHOTO: HARJONODJOYOBISONO)

necessary to prevent the entry of rotorganisms and to reduce water loss.Wound healing occurs most rapidly at 15-18°C, with 95 percent humidity, andrequires 5-20 days.3Pile potatoes without refrigeration in

several small piles rather than in onelarge heap. Large amounts tend to heatbecause ventilation cannot reach thecentre of the pile, thus lowering qualityand shortening storage life.3Never store potatoes in close proximity

to fruit – hormones produced by ripeningfruits will cause the potatoes to sprout or rot prematurely.3Storing ware potatoes at a temperature

of less than 6°C stimulates the conversionof starch into sugars, giving the tubers an unnaturally sweet taste. Moreover,sugars will interact with free amino acidsduring frying, producing dark productswith poor taste.

3Promote improvements in harvesttechnologies to minimize bruising,improve tuber quality and storability.3Develop and promote low-cost storage

technologies suitable to small-scale farmsin the tropics and subtropics.3Carry out ex-ante cost-benefit studies on

small or large scale refrigerated storagecapacity.




A study was conducted recentlyacross the East African region toestimate the potential size ofthe market for fresh andprocessed potato in selectedcities in Burundi, Ethiopia,Kenya, Rwanda, Tanzaniaand Uganda. Findings show

that establishment of a viableindustry for processed potatohinges on improvementsin quality standardsand packaging and premiumprices for quality produce.The study said that expandedpotato processing would

increase employmentopportunities in city areas.With half of East Africansexpected to live in urban areasby 2015, the boom in demandfor potato chips and French frieslooks set to continue.

The Participatory Market ChainApproach (PMCA) wasdeveloped by the Papa AndinaRegional Initiative conducted inBolivia, Ecuador and Peru by theInternational Potato Center (CIP).The aim of Papa Andina is toimprove the competitiveness ofpotato market chains and smallpotato producers. PMCA has

proven effective instrengthening innovationcapacity and developing marketchain innovations that benefitsmall farmers as well asprocessors and distributors.Valuable capacities forinnovation have beendeveloped, particularly in therealms of knowledge, attitudes,

skills, and social capital. Thesenew capacities are potentiallyvaluable assets for stimulatingfuture innovations in marketchains. The benefits of the PMCAhave stimulated considerableinterest in the approach amongR&D organizations, policymakers and market chain actors.

Learning to innovate and engagewith markets, and to becomemore competitive are mainchallenges facing small-scalefarmers. However, in many low-income developing countries,potatoes are typically marketedthrough fragmented chains withlittle coordination and poorinformation flows, giving rise tohigh supply risks and hightransaction costs. Average yields

remain far too low to enablesmall-scale potato growers toproduce a marketable surplus,preventing them from increasingtheir participation in potatomarketing systems. In addition,limited storage and transportfacilities can adversely affect thequality of tubers after harvest.Efforts to enhance the value chainwill only be successful providedthere are substantial levels of

public and private investment inthe subsector, such as in breedingprogrammes, infrastructuralimprovements and initiatives tosupport and coordinate activitiesalong the chain. Policy-makersshould increase support to thesubsector, by – for example –extending to the potato sub-sector policies and resourcestraditionally focused on cerealsand on cash crops for export.

Adding value in East Africa

Enhancing the value chain and markets

The Participatory Market Chain Approach

With its adaptability to a widerange of uses, the potato has apotentially important role to playin the food systems of developing

countries. In fact, in many countries, growthin urban populations, rising incomes anddietary diversification have led to rapidlyincreasing demand for potatoes from thefresh market, fast food, snack andconvenience food industries. The structuraltransformation of agriculture-basedeconomies into more urbanized societiesopens up new market opportunities forpotato growers and to their trading andprocessing partners in the value chain. Inorder to tap such potential, an efficientvalue chain for potato needs to beestablished.

Often potatoes are purchased in thecountryside by traders from cities, with verylimited negotiation and with prices decidedat the farm gate, resulting in an unevendistribution of income along the valuecreation chain. This leads to insufficientbuying power among potato growers and thedraining away of capital that could beinvested in rural areas to buildinfrastructure such as roads and improveeducation.

3Carry out consumer surveys to identifygrowing market segments and types ofproducts likely to be in demand in thenear future.

Good practices

3Develop and select cultivars that arepreferred by consumers, processingindustries or local exporters.3Use appropriate post-harvest practices and

storage facilities to keep tubers in theirmost edible and marketable condition.3To increase value, provide high quality

ware potatoes or potato products toconsumers.3Use simple market-oriented technologies

that transform potato tubers into stablehigh quality products.3Encourage farmer participation in

producer groups and organizations inorder to increase their marketcompetitiveness and bargaining capacityand strengthen their position within thepotato value chain.

3Support participatory market chainapproaches for potato (see box).3Develop innovative marketing and

utilization techniques linking small scalepotato producers to new marketopportunities.3Promote mechanisms and approaches to

link technology suppliers with farmers’needs, based on opportunities identifiedwithin a market chain framework.3Organize growers in cooperatives for joint

purchase of inputs such as fertilizers andfor joint processing and trading so that agreater proportion of the potato valuechain remains in the hands of producers.



Value addition and markets


POTATO HARVESTING. (PHOTO: FAO)

The health, safety and welfare offarmers and consumers are vitalassets for the sustainable developmentof the potato subsector and

agriculture throughout the world. Particularattention must be paid to reducing risksassociated with the use of pesticides, toolsand machinery, and to ensuring thatpotatoes are produced and handled in amanner that does not harm theenvironment and the health, and safety offarmers and consumers.

Creating awareness of food safety andenvironmental issues should be part ofcommunity education programmes inrural areas.Train farmers in the efficient and safe useof pesticides, fertilizers, tools andmachineryEncourage them to invest in potatofarming, and in improving their livingstandards.Use decision support tools to reduce theamounts of biocides used in potatoproduction and thus reduce the risks ofdangerous levels of residues in harvestedor stored produce.Ensure that medical doctors and hospitalsin rural areas are able to recognizesymptoms of agrochemical poisoning andtreat it.

Good practices

Farmers groups should considerdeveloping partnerships with public sectorand development organizations to addresshealth and safety issues.Create services that collect pesticidepacking material and unused redundantstocks for centrally organized destruction.Inform farmers and households aboutproper pesticide labelling and thedesignation of containers used to mixpesticides, and the use of properlyfunctioning protective equipment andclothing.Establish a list of chemicals that aregenerally safe for various crops and a“black list” of chemicals that aredangerous and are forbidden.Set maximum residue levels foragrochemicals that are permitted for usein the country.Organize farmers groups in cooperativesto promote their interests and call forpositive marketing regulations, lowerduties and taxes on imported tools andequipment, and better access to credit toimprove their self-reliance and welfare.



Farmers’ health, safety and welfare

job_i1127_e_int 23/11/09 11:39 Pagina 65

POTATO BAGS WAITINGTO BE SENT BY TRAIN

FROM SHIMLÀ, INDIA.(PHOTO: S. PAUL)

SECTION 4

Implicationsfor policyand researchPotato production in the developingworld grew from 85 million tonnes in1991 to 165 million tonnes in 2007.To sustain that exceptional growth,policy and research must shift from thetraditional focus on raisingproduction to a broader approachaimed improving rural incomes,livelihoods, nutrition and health, whileconserving the natural resource base.


Although the potato has been astaple food for Andean peoples formillennia, many modernPeruvians prefer rice or breadmade from imported wheat. Tosupport domestic potatoproduction, the Government ofPeru has offered low-incomepotato farmers emergency creditto maintain production andencourages Peruvians to eat agreater proportion of potatoes,thus boosting demand and prices.The government is also promotingthe use of potatoes to makebread. A government-run foodcompany produces each day morethan 12 000 loaves made fromone-third boiled and mashedpotatoes and two-thirds wheatflour. Replacing a third of thewheat flour with mashed

potatoes or potato flour results ina soft, tasty bread that keeps well,and is more nutritious andcheaper than bread made fromwheat only. Since January 2008,Peru’s prisons and many publicschools have been serving potatobread (papa pan). It is also sold byPlaza Vea, a Peruvian supermarket

chain. More recently, the chief ofPeru’s Sierra Exportadora, whichsupports farmer co-operatives,has called on Ministers to approvethe construction of 100 potatoflour production plants to supplysmall and medium bakeries andeven to export potato flour toEurope, Japan and the USA.

“Papa pan”, a pro-potato policy solution

POTATO STARCH.(PHOTO: JANGSU CORP.)

Globally, potato production is growingat a rate of 2 percent annually whilein developing countries, growth isestimated at around 5 percent.

Sustaining the exceptional growth in potatoproduction of the past two decades – from268 million tonnes in the early 1990s to 325million tonnes in 2007 – and the expansionof potato domestic trading in developingcountries depends on choosing the rightpolicy and research options for developmentof the agricultural sector and potato-basedfarming systems. The policy and researchagenda is expected to shift from thetraditional focus on raising productivity to abroader approach that makes a realcontribution to the fight against hunger,poverty and environmental degradation byimproving rural income, livelihoods,nutrition, health, and conserves the naturalresource base.

Policy reforms are a needed if developingcountries wish to develop and promote asustainable potato industry and agriculturalsector. This implies overcoming currenttrade barriers, including the lack ofharmonized transit charges and customsdocumentation. It also implies overcomingcurrent barriers to sustainable productionintensification based on good agriculturalpractices.

Policy makers need to be more aware ofthe contribution that the potato is alreadymaking to development and food security,and of its importance as a staple food andcash crop in developing countries. In theprocess of revising poverty reduction strategypapers (PRSPs), and in formulatingstrategies for agricultural development, theyshould take into account the needs andpotentials of the potato subsector andsupport its more active engagement in the

development process.One important policy aim in developing

countries should be to enhance the value ofpotato production by establishing linksbetween farmers and food processors,improving credit availability, and fosteringpublic-private partnerships for technologyinnovation. By engaging interested partnersfrom the public and private sectors and civilsociety, policy can facilitate the developmentof focused country-level programmes,projects and activities to support asustainable potato subsector.

Policy should also create a regulatoryenvironment conducive to sustainablepotato development through support forknowledge enhancement and research,application of best management practices,and sharing and promotion of proven andadvanced potato technologies througheducation, extension and training.

Policy should address constraints onpotato-based production systems byfavouring the introduction of good qualityplanting material and potato varieties moreresistant to insect pests, diseases, waterscarcity and climate change, farmingsystems that can make optimum use ofnatural resources, seed certification schemesand soil testing laboratories.

Policy will also have to secure financialcommitments from national governments,donors and the private sector to invest inpotato-based systems and value chains. Indoing so, policy makers should encourage astronger commitment by the potatocommunity to potato subsectordevelopment.

69IMPLICATIONSFOR POLICYAND RESEARCH

Building support at policy level


IN VITRO PLANTSOF POTATO.

(PHOTO:YOAV FRIDLANDER)

Accelerated and sustainabledevelopment of the potato subsectorin developing countries requiresincreases in the productivity,

profitability and sustainability of potato-based farming systems. This implies a newand vigorous research for developmentagenda.

The way forward for potato research indeveloping countries will include a numberof priority areas. First, the lack of adequatequantities of clean seed is a majorbottleneck to improved productivity.Promising results have been obtainedthrough extension efforts that promote theuse of “positive selection” and small-scaleseed plots. Other research work aimed atimproving the quality of farmers’ seedthrough novel technologies such asaeroponic production of clean seed tubershas yielded positive results. Strongconsideration should be given to fosteringpublic-private sector partnerships as astrategy for getting potato seed systemsmoving in developing countries. Alsorecommended are ex-ante assessments ofthe potential return on investments bycalculating the impact of new adaptedvarieties and cleaner seed.

In many countries, investments areneeded in laboratories for the diagnosis ofpotato diseases, for measuring mineralconcentrations in soils, manure andfertilizers, and for determining thecomposition and concentration of activecompounds in herbicides, pesticides,fungicides and nematicides.

Legislation is needed in many countriesto set quality standards for seed and tointroduce or enforce mechanisms forcertification through accredited laboratories.Legislation may also be needed to protectpotato breeders’ rights.

The potential effects of climate changepose a threat to the levels and stability ofpotato yields. Heat and drought resistanceshould be considered in breedingprogrammes along with other key traitssuch as late-blight resistance, virusresistance, earliness and culinary qualities.Hence, research needs to provide a broaderrange of genetic material that meets site-specific criteria, is adaptable to changingenvironments, and meets new demandsfrom emerging markets for processed foodproducts, non-food ingredients and starchfor industry. The growing demand for potatowith specific characteristics for a particularprocessed product must be taken intoconsideration, but should only be pursuedafter a careful analysis of market prospects.

The potato subsector faces a growingchallenge from more aggressive strains oflate blight and many developing countrieshave a limited capacity to control the diseasethrough fungicide application. Continuedresearch on resistance breeding andintegrated management strategies isessential, while support is needed for scalingup LB control technologies andmethodologies developed by CIP.

It is unlikely that resistance to latentbacterial wilt infection will be availablethrough conventional breeding in the near


Research for development agenda


FROM THE ESSAY,“HARVEST OF NATIVE

POTATOES, PERU.” (PHOTO: EITAN

ABRAMOVICH SAMESAS)

future. Research on integrated managementto control bacterial wilt needs to focus ondesigning improved detection technologies,developing recommendations that farmersare willing and able to adopt, and exploringoptions for suppressing the disease throughimproved soil fertility and healthmanagement (e.g. sanitation measures andclean seed). Participatory approaches tofarmer empowerment and learning, such asFarmers’ Field Schools (FFS) for IPM andIDM, are required in order to reach asignificant number of potato growers.Progress in the sequencing of the bacterialwilt genome might lead to new ways ofcontrolling the disease in the long term.

The development of conservationagriculture technologies and practices forpotato-based systems presents opportunities

for both public and private sector research.All aspects require increased researchsupport.

Finally, improving the incomes of small-scale potato growers depends on increasingdemand-driven opportunities anddeveloping value-chains which include allmarket chain actors, from input suppliers toconsumers. Linking farmers to markets,especially high-value supermarkets andrestaurant chains, can substantially increasethe profitability of the potato cultivation.This requires technological innovation atmany points in the value chain, includingintroduction of improved varieties and moreefficient post-harvest processes, as well astechnical assistance to ensure timelyproduction and supply of adequatequantities of high quality potato products. 73

IMPLICATIONSFOR POLICYAND RESEARCH


Potato seed producers arguablyconstitute the most critical link inthe potato chain. For it is their roleto ensure that the chain hasaccess to sufficient quantities andqualities of planting material tomeet the needs of potato growers,processors and traders. In orderfor this group to successfullyparticipate in the value chain,they need yield-improving andinput-saving technologies to helpclose the persistent potato “yieldgap” and to reduce per tonneproduction costs. Productioninitiatives can be strengthenedgreatly by germplasm researchfocused on specific end uses,tissue culture, rapid multiplicationof planting material, insect pestand disease resistance (includingenhancing resistance to prevalentdiseases such as late blight by

combining conventional plantbreeding techniques withbiotechnology) and the formationof producer groups to shareexpertise and to strengthenbargaining power. The continuousgeneration and diffusionof improved varieties is importantif the potato subsector is toflourish. The expansion of potatocultivation will also be facilitatedby improved irrigation supply,chemical fertilizers, cold storage

facilities, and transportinfrastructure. In addition,the market price of potato is oftensubject to very limitednegotiation and is often decidedat the farm gate. Inefficientand unfair pricing often resultsin producers failing to respondto market incentives, stiflingefforts to increase productivityand undermining the necessaryon-farm investments inproduction.

Challenge of a better functioning value chain

ASSEMBLINGTHE POTATO

HARVEST, INDONESIA.(PHOTO:

FERNADIE LILI)

Extending the benefits of potatosubsector in developing countriesrequires action on a wider front. Thebest strategy for achieving this is to

engage the international community inagricultural development that benefitssmall-scale farmers, who make up themajority of the world’s most poor andhungry. Such commitment will make astrong contribution to achievement of thefirst of the United Nations MillenniumDevelopment Goals, to half the proportion ofthose living in extreme poverty and hunger.

As a lead UN agency for agriculture andrural development, FAO will be a key partnerin that process, by advising on policies andstrategies to modernize the potato subsector,sharing its extensive knowledge of potatofarming systems, promoting appropriatetechnology for sustainable intensification of

production, and forging links amongdecision makers, producers, processors andmarketing chains.

CIP will play a key role through itscampaign for a new research fordevelopment agenda that puts potato scienceat the service of the poor. The new agendaseeks to boost potato yields in developingcountries by working with them to providehigher quality planting material, bettervarieties drawn from a broader base ofpotato genetic resources (including the richstorehouse of Andean varieties), andimproved crop management practices. CIPis calling for a renewed sense ofresponsibility for conservation of the potatogene pool and take concrete steps to ensurethat developing countries acquire thecapacity to utilize it in a sustainablemanner.


Partnerships for policy and research

BAMBOO BOAT,THE PHILIPPINES.

(PHOTO:MARLENE SINGH)

SECTION 5

Potato fact sheetsTo deepen understandingof the potato’s role in world agriculture,the economy and global food security,FAO specialists compiled a seriesof factsheets on key issuesin potato development.


Bernet, T., Thiele, G. & Zschocke, T. 2006..Participatory Market Chain Approach (PMCA):User Guide, International Potato Center (CIP),,Lima, Peru.

Beukema, H.P. & van der Zaag, D.E. 1990.Introduction to Potato Production. PUDOC.Wageningen, The Netherlands.

Caldiz, D. O. 2007. Producción, cosecha yalmacenamiento de papa en la Argentina. BASFArgentina S.A.—McCain Argentina S.A. (1st ed.).Balcarce, Argentina.

CIP. [International Potato Center]. 2007. Root andTubers: The overlooked opportunity, AnnualReport. CIP, Lima, Peru.

CIP. 2008. Potatoes. Fact sheet. CIP, Lima, Peru.

CIP. 2008. Fifty potato facts. Fact sheet. CIP, Lima,Peru.

CIP. 2008. Potatoes and economic policy. Fact sheet.CIP, Lima, Peru.

CIP. 2008. Potatoes and the environment. Fact sheet.CIP, Lima, Peru.

CIP. 2008. Potatoes and biodiversity. Fact sheet. CIP,Lima, Peru.

CIP. 2008. Why potatoes. Fact sheet. CIP, Lima, Peru.

FAO. 1998. Storage and processing of roots and tubersin the tropics. FAO, Rome, Italy.

FAO. 2009. New light on a hidden treasure. IYP end-of-year review. FAO, Rome, Italy.

Gildemacher, P., Demo, P., Kinyae, P.,Nyongesa, M. & Mundia. P. 2007. Selecting thebest plants to improve seed potato. LEISAMagazine 23(2): 10–11.

Guardia, Sara B. 2004. La flor morada de los Andes.Universidad San Martín de Porres, Lima, Peru.

Horton, D. 2008. Facilitating pro-poor market chaininnovation: An assessment of participatory marketchain approach in Uganda. Working paper. CIP,Lima, Peru.

Low, J., Baker, I., Bornierbale, M., Crissman,C., Forbes, G., Lemaga, B. & Priou, S. 2007.Emerging trends and advances in potato researchrelevant to defining the way forward for the potatosubsector in Sub-Saharan Africa. African PotatoAssociation Conference Proceedings 7: 1-17.

Mancero, L. 2007. Potato chain study. FAO-ESAE-CIP project document.

Nganga, S. & Shideler, F. 1982. Potato seedproduction for tropical Africa. CIP, Lima, Peru.

Posadas, A., Rojas, G., Malaga, M., Mares, V. &Quiroz, R. 2008. Partial root-zone drying: Analtrnative irrigation management to improve thewater use efficiency of potato crops. Workingpaper. CIP, Lima, Peru.

Rouselle, P., Robert, Y. & Crosnier, J.C. 1996. LaPomme de Terre: production, amélioration,ennemis et maladies, utilisation. INRA, Paris,France.

Stark, J.C. & Love, S.L. (eds.) 2003. PotatoProduction Systems. University of IdahoExtension. USA.

Van der Zaag, D.E. 1982. Seed potatoes, sources ofsupply and treatment. NIVAA, The Hague, TheNetherlands.

Wachira Kaguango, Gildemacher, P., Demo,P., Wagoire, W., Kinyae, P., Andrade, J.,Fuglie, K. & Thiele, G. 2008. Farmer practicesand adoption of improved potato varieties inKenya and Uganda. Working paper. CIP, Lima,Peru.

Warsito Tantowijoyo & van de Fliert, E. 2006.All about potatoes: A Handbook to the Ecology andIntegrated Management of Potato. CIP-ESEAPRegion & FAO Regional Vegetable IPM Programin South and Southeast Asia.

Bibliography

International Year of the Potato SecretariatPlant Production and Protection DivisionFood and Agriculture Organizationof the United NationsViale delle Terme di Caracalla00153 Rome, Italy

[email protected]

“Snapshots” of selected best practices and examples of successful approaches in developing countries

Factors constraining the potato subsector, good agricultural practices for potato production, key indicators of sustainability, and implicationsfor policy and research

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Sustainable potato production

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