AgriCulture & rurAl DevelopmeNt
JOINTnotes 64930
iSSue 56
mAy 2011 missing food
the Case of postharvest grain losses in Sub-Saharan Africa
Rising and increasingly volatile food prices—spiking the late 1970s, has become widespread throughout
for the second time in three years—combined with much of the continent. The high-yield crop variet-
heightened uncertainty about future prospects for ies subsequently introduced into Africa are both
food availabilities, are raising alarm about food secu- dependent on external inputs and more susceptible
rity, particularly in low-income, food-deficit countries, to pests than traditional varieties. Land fragmen-
most located in sub-Saharan Africa. And, after a tation has continued unabated in most African
decade of neglect, the world is once again reminded countries, and the corresponding decrease in farm
that the crisis is not only the result of production size has been accompanied by declining soil fertility.
failures, but of losses and waste as well. A substan- Weather patterns have become more erratic, leading
tial proportion of the food produced in the world is to recurring failed harvests and food shortages. And
never consumed. It decays or is attacked or infested
finally, the expertise in postharvest issues that was
by pests, fungi, or microbes. Consequently, posthar-
once cultivated by multilateral investment has by
vest losses have again come to the forefront in the
now largely eroded, as the result of the subsequent
discussions on food security. Development agen-
period of underinvestment that followed.
cies, such as the Food and Agriculture Organization
(FAO)—which set up the Action Program for the In 2009, the World Bank, in collaboration with FAO
Prevention of Food Losses in 1978—and the World and the Natural Resources Institute in the UK,
Bank see investment in postharvest technologies undertook an analysis of postharvest issues to
as an essential element to increasing food security
assess the current state of knowledge regarding
in Africa. Now the reversal of real commodity price
those issues, and to formulate a series of practical
declines may prompt increasing investment and the
recommendations for scaling-up effective methods
revitalization of research and training to promote
and technologies to reduce postharvest losses.
postharvest technologies. Postharvest losses also
feature prominently in recent global initiatives, in-
cluding the Comprehensive Framework for Action is-
sued in 2009 by the United Nations High-Level Task
Force on the Global Food Security Crisis, the Global
Agriculture and Food Security Program endorsed by
the World Bank in January 2010, and the recently
reformed Committee on World Food Security.
Much has changed in Africa since the 1970s. Com-
petition from international markets is appreciably
greater in the wake of market liberalization. In most
African countries the state has withdrawn from
grain-marketing activities that once provided the
commercial sector with technical support in grain
handling and storage. An emerging private sector
has been instrumental in developing more sophisti-
cated grain value chains. Regional integration has led
to easier movement of grain. HIV/AIDS and wide-
spread urbanization have wielded major impacts on
the availability of rural labor. The larger grain borer,
a devastating storage pest that was accidentally in-
troduced into Tanzania from Central America during Photo: Rick Hodges, NRI.
A variety of stakeholders and institutions that are engaged lack of storage altogether. They often include bad handling
in these issues contributed lessons from their experience, procedures as well, particularly drying techniques that do
providing useful insights that can guide the design and not sufficiently reduce moisture levels in the grain. These
conduct of effective postharvest strategies. These included practices lead to contamination by food-borne pathogens
the Zambia Food Reserve Agency, the Eastern Africa Grain and toxins, infestation by insect pests, and attacks by rats,
Council, the Grain Traders and Processors Association in birds and other animals. Governance-related causes include
Malawi, the World Food Programme, the International Fund bad policies (or missing policies) in the areas of procure-
for Agricultural Development, and Premium Foods Ltd. of ment, transport and storage, and distribution. There is often
an absence of mechanisms for dealing with cash flow needs
Ghana. The report, Missing Food: The Case of Postharvest
(such as warehouse receipts systems). Mismanagement or
Grain Losses in Sub-Saharan Africa, examines the
malfeasance in handling and financing can also be contribut-
evolution of public and private sector responses to
ing governance-related factors; as can management prob-
postharvest losses over the last two decades, as well as the
lems in grain storage and price-stabilization programs.
determinants of technology uptake. It is intended to build
upon the African Development Bank’s Postharvest Loss Postharvest losses can be further categorized into physical,
Initiative for Sub-Saharan Africa. quality, and economic losses. Physical losses refer to reduc-
tion in the volume or weight of the grain due to such factors
as shrinkage, attack by rodents, and insect infestation. Qual-
the eXtent of postharvest
ity losses refer to deterioration in the condition of the grain
losses of graIns In afrIca
which impacts negatively on attributes such as appearance,
The report classifies the causes of postharvest losses taste and texture, nutritional value, and product safety. An
broadly into two categories, technical causes and gov- important safety-related quality loss is contamination by
ernance-related causes. Technical causes include poor mycotoxins. Economic losses are closely linked to quality
harvesting methods, inadequate storage, and in many cases, and refer to reductions in unit sales price and the inability of
grain to access higher value markets.
Because these losses occur at every point along the supply
chain, quantifying total losses is challenging, and estimates
have ranged widely, including some as high as 50 per-
cent. The African Postharvest Losses Information System
(APHLIS) is a highly-developed analytic tool that calculates
reliable estimates about the scale of these losses.1 The
APHLIS information platform draws postharvest loss esti-
mates from national researchers, and its findings indicate
physical grain losses (prior to processing) of between 10
and 20 percent, well below the 40-to-50 percent estimates
often cited in development literature. Yet these losses are
still highly significant. In East and Southern Africa, APHLIS
estimates that losses are valued at US$1.6 billion annually,
which is about 13.5 percent of the $11 billion total value
of grain production in the two regions. While no parallel
estimates are available for grains in Central or West Africa,
assuming that losses there are of a similar magnitude, the
value of postharvest losses throughout sub-Saharan Africa
may amount to close to $4 billion a year, out of the estimat-
ed total $27 million averaged between 2005 and 2007. This
estimated $4 billion in postharvest losses exceeds the total
value of food aid that Africa received over the last decade.2
It is on a par with the $3-to-$7 billion in cereal that Africa
imported annually between 2000 and 2007. The estimated
losses would allow feeding 48 million people for a year at
the minimum 2,500 calories per day.
Given this magnitude of postharvest losses, reducing losses
Winnowing Grain. Photo: Jim Richardson. needs to be considered an integral part of food security,
2
alongside raising productivity. Moreover, it is likely that reduc-
ing losses will be more cost effective and environmentally
sustainable than a corresponding increase in production—
even accounting for the costs involved in achieving those
reductions. Assuming a mere 1 percent reduction in posthar-
vest losses, annual gains of US$40 million are possible, and
producers would be a key beneficiary. Therefore, improving
postharvest handling affords the opportunity to achieve a
“triple win�?: increasing food security and supporting liveli-
hoods of the rural poor; increasing the quality and quantity of
grains to feed rapidly growing, urban-consumer populations;
and saving valuable and scarce water and land resources.
IncreasIng adoptIon rates of
postharvest technologIes
A variety of practices and technologies are available for
reducing postharvest losses, including hermetically sealed
bags, metallic silos, and other storage containers. House-
hold silos are a particularly effective device for protecting
stored grain from pests and fungi and, together with proper
postharvest management, allow grain to be stored for long
periods without appreciable loss of quality. Local tinsmiths
can readily be provided instruction in silo construction.
However, the key to good storage is the adoption of good
hygiene and postharvest management practices; these can
be implemented at minimum cost, but do require compre- A maize farmer and trader in Embu, Kenya, shows her dry, clean maize grain,
which she is storing in a metal silo. Photo: CIMMYT (CC BY-NC-SA 2.0).
hensive training and awareness raising of all actors along
the postharvest chain. During the 1970s and 80s, govern-
ments and donors employed a technology push orienta- technologies have been transferred from Asia, where labor
tion in their promotion of postharvest technologies. These is relatively scarce and rural wages are relatively higher,
generally consisted of stand-alone interventions involving and where rice is the most prominent crop—not maize,
a particular technology or marketing arrangement that was sorghum, or millet. In African contexts, many of these
considered appropriate in addressing the constraints of a technology packages have proven financially unsustainable.
particular target group. Recent examples of this approach Some postharvest interventions have misidentified
include the triple bagging of cowpeas, community cereal the most important constraints faced by actors along
banks, and mechanized harvesting and cleaning equipment the supply chain, and have falsely assumed there are
to reduce losses for wheat and maize. These interven- economics incentives in place for reducing losses. Some
tions were often complemented by technical assistance on have attempted to facilitate change within timeframes that
improved farm management within the broader postharvest proved unrealistic, such as the three-year project cycle
system. During the mid 1990s, market oriented approaches typical of many interventions. A broader class of factors
emerged focusing strongly on the market as the driving inhibiting the uptake of new postharvest technologies relate
force for postharvest improvements and based their suc-
to cultural acceptability, such as the preference of some
cess on good business practices and facilitating farmer link-
local populations to store food stocks within the household
ages to markets. Value chain coordination emerged largely
rather than in a warehouse or a communal store in order
out of this broader operational perspective. The adoption of
to prevent theft. Given the prominent role of women in
this approach can lead to greater system efficiency, reduc-
postharvest management in most African settings, targeting
tion of postharvest losses, and a clearer understanding of
women in the dissemination of new technologies and
the various participants along the value chain, opportunities
techniques should be an important practical consideration
for cooperation, and the benefits derived through improve-
in project and message design. The socioeconomic
ments in the postharvest system.
components of postharvest projects cannot be small,
However, adoption rates of new postharvest technologies underfunded afterthoughts, but recognized for what they
and practices remain low in Africa. Some of the are—critical determinants of success or failure.
3
range of services to their members, and in identifying
and accessing new markets. The public sector also has
a significant role—chiefly in providing public goods such
as infrastructure—which are instrumental in creating and
enabling investment climate and in facilitating the provision
of agricultural research and extension services that target
smallholder producers. For net deficit grain producers who
are unable to pay for such services, improving basic storage
hygiene and management can be undertaken with mini-
mal financial cost using simple techniques they can learn
through radio broadcasts, newspapers, or videos. And more
direct support to these producers is an area in which a case
for subsidized extension can be plausibly argued.
Moving forward, the ability to measure success is an
increasingly important requirement. The current paucity of
data on impacts deprives donors of the information they
need to justify continued investment in the area of posthar-
Transporting Grain Uphill in Kenya. Photo: Julian van Mossel-Forrester.
vest loss reductions. There is also a need for international
coordination in developing new postharvest technologies
IdentIfyIng optImal InterventIons: and in optimizing postharvest systems. The desirability of
usIng the value chaIn lens a revitalized postharvest community of practice to evaluate
innovations, assist in scaling them up, and to document
Why do farmers tolerate postharvest losses? Up to now,
practical lessons and good practices is the subject of a
demand for better-quality grain remains low in Africa, and
growing consensus between development organizations
farmers who invest in improving the quality of grain they
and private sector representatives. Such a community
deliver are mostly not rewarded for doing so by the mar-
could be instrumental in informing investment programs,
ket. However, a number of trends are reversing this un-
and in reversing the current trend of declining postharvest
responsiveness from the demand side. Urbanization, the
expertise in international development circles. In helping
emergence of a more affluent middle class, and changing
us to understand the scale of the problem, the APHLIS da-
consumer preferences are among the most prominent
tabase may, with time, become an archive of projects and
trends, and provide suppliers with an important oppor-
studies dealing with postharvest grain losses, and perhaps
tunity to increase incomes if they are able to satisfy the
feed into the FAO Information Network on Postharvest
required quality standards. Quality-conscious institutional
Operations (INPhO) systems, which contains information
buyers, such as the World Food Programme, reinforce
on postharvest technologies for all crops, and which is also
this opportunity.
expected to serve as the anchor of community of practice,
For donors, systematic interventions that address the with information on projects, meetings, contacts, as well
value chain as a whole lead to a more complete under- as on tools to guide investment decisions. This approach
standing of how products, information, and finance flows, would go a long way toward preserving the institutional
and of how actors along the value chain interact. While memory on postharvest interventions for grain value chains
farm-level, postharvest systems necessarily remain an im- and possibly serve as the foundation of a regional learn-
portant focal area, this more comprehensive perspective of ing alliance that builds bridges between the research and
actors and their incentives enables practitioners to identify development communities.
other high-payoff entry points as well. Private sector actors
This Note is prepared by Nancy Morgan and Gunnar
prove to be influential agents in adopting new postharvest
Larson. It is based on the report Missing Food: The
technologies, and in requiring their suppliers to do so too.
Case of Postharvest Grain Losses in Sub-Saharan
They play a central role in establishing warehouse receipt
Africa. Find the report at www.worldbank.org/ard.
systems, in forming trade associations that provide a wide
1 The Postharvest Losses Information System was created within the framework of the project “Postharvest Losses Database for Food
Balance Sheet Operations.�? This was financed by the European Commission within the work program of its Joint Research Centre (Italy)
and implemented by an international consortium.
2 Estimated at $6.1 billion over the 1998–2008 period.
1818 H Street. NW Washington, DC 20433 www.worldbank.org/ard