aflatoxins agriculture and technology solutions available for abating the aflatoxin challenge...
TRANSCRIPT
www.iita.org A member of CGIAR consortium
Ranajit Bandyopadhyay
IITA, Ibadan, Nigeria
Aflatoxins, Agriculture and Technology
Solutions Available for Abating the Aflatoxin
Challenge
Mapping Aflatoxin Contaminated Maize food and Feed
Chain: Developing a Roadmap for Safe Food and Feed for
Improved Health and Nutrition, New Delhi, 15 Jan 2014
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We work with partners in
Africa and beyond to reduce
producer and consumer risks,
enhance crop quality and
productivity, and generate
wealth from agriculture.
What we do
Who we are
Our research for development
activities have delivered over
70% of the CGIAR's positive
impact on the food security and
livelihoods of over 500 million
people in sub-Saharan Africa
and beyond.
• Highly toxic metabolite produced by the ubiquitous Aspergillus flavus fungus
• The fungus resides in soil and crop debris, infects crops and produces the toxin in the field and in stores
Aflatoxin Facts
• Contamination possible without visible signs of the fungus
• Fungus carried from field to store
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• Unlike most fungi,
Aspergillus flavus is favoured
by hot dry conditions.
• The optimum temperature
for growth is 37 C, but the
fungus readily grows
between the temperatures of
25-42 C, and will grow at
temperatures from 12-48C.
• Toxin contamination more
when night temperatures are
high
• Drought stress predisposes
plants to aflatoxin
Disease Development & Weather
Source: www.aspergillusflavus.org
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Aflatoxin Contamination Occurs in
Two Phases
Phase I: Before Crop Maturity
Developing crops become infected.
Associated with crop damage (insect, bird, stress).
Favored by high temperature (night) and dry conditions.
Phase II: After Crop Maturity
Aflatoxin increases in mature crop.
Seed is vulnerable until consumed.
Rain on the mature crop increases contamination.
Associated with high humidity in the field & store, insect
damage, and improper crop storage or transportation.
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Pre-Harvest Problem
Aflatoxin (ppb)ppb) Peanut (n = 188) Maize (n = 241)
Distribution (% samples)
> 4 54 70
> 10 41 52
> 20 29 24
Descriptive statistics (ppb)
Minimum < LOD < LOD
Maximum 3487 838
Mean 111 33
LOD = Limit of Detection; States sampled: Nassarawa,
Katsina, Kaduna, Kano, Bauchi, Jigawa & Niger
Aflatoxin in Groundnut and Maize at Harvest, 2012, Nigeria
Increases in store
Contamination is most severe at low elevations and during dry periods. During drought the zone with contamination expands.
35°N
35°S Zone with Perennial Contamination Risk
Aflatoxin Contamination: A Perennial Concern in Warm Climates
acute
acute hepatic necrosis, cirrhosis,
carcinoma
Death; 108 in 1974 in Gujarat, 250
to 15,000 ppb aflatoxins in corn
chronic
carcinogenic
anti-nutritional
immune-suppressive
gut integrity?
BBC 2004, Gong et al 2004, NIEHS 2010
underreported
unknown
Human Health Effects
Kenya
district samples total aflatoxin levels (ppb)
<20 21-99 100-1,000 >1,000
Makueni 91 35 13 40 12
Kitui 73 38 21 32 10
Machakos 102 49 25 23 3
Thika 76 66 17 13 4
Total 342 47% 19% 27% 7%
CDC and Kenyan Ministry of Health 2004
Total samples % samples with aflatoxin levels (ppb)
<5 5-15 16-30 >30
2074 53% 6% 15% 26%
Bhat et al. 1997; Food Add. & Cont.
India
Aflatoxins in Markets
Aflatoxin and Poultry (Broilers)
Aflatoxin
levels in
feeds in
Nigeria
Aflatoxin level (ppb) Samples (%)
<20 (safe) 38
>20 to 100 (up to 5x) 14
>100 to 500 (up to 25x) 41
>500 to 1,000 (up to 100x) 7
AF-free diet 500 ppb AF diet
AF-free
diet
500 ppb AF diet
~40% reduction in live weight (8 weeks)
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Prevalence of Aflatoxin
• Several African staple commodities affected
• High human exposure in Africa – mother to baby
• Levels and frequency of occurrence high
• Concern for food and feed processors, government
and emergency food reserve agencies, school-
feeding
• Aflatoxins disproportionately impact the poor
• Highly toxic strains, conducive environmental
conditions, traditional farming methods and
improper grain drying and storage practices,
unregulated markets
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Aflatoxin
Intervention
Medical
Agriculture
Surveillance
Enterosorption
Pre-harvest
Food processing
e.g. Novasil clay
Agriculture & Medical Prevention of Aflatoxin-
related Food Security and Health Effects
(Adapted from Wild and Hall, Mutation Res., 2000)
Awareness
Regulation
Provision of safe food
Early diagnosis
Post-harvest
Pre- and post-harvest Interventions for
Aflatoxins
• Pre-harvest
– Resistant cultivars, if available
– Biological control, e.g., aflasafe
– Irrigation and water conservation practices
• Post-harvest
– Sorting
– Insect control
– Improved drying and storage
– Aflatoxin testing
– Food / feed processing / detoxification methods / binders
– Alternative uses including blending
– Market development
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Integrated Management
The elements are:
• Awareness – entire range of value chain participants
• Advocacy – regional, national, investors
• Technology
• Training – farmers, transporters, traders, regulators, consumers
• Policies – standards, harmonization, trade
• Institutions – regulators, markets, testing, private sector
• Trade / Markets – food/feed processors, poultry/fish industry
• Public good – home consumption; urban and rural markets; government procurement, HGSF
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Resistant, High-Yielding Hybrids
334 396 400 488 800 809 816 956
5474 5671
6438 6087
5685
7115
6040 5891 5743
5662
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
Hybrids
Aflatoxin (ppb)
Grain yield (kg/ha)
Afl
ato
xin
(p
pb
)
Gra
in y
ield
(k
g/h
a)
Less toxin – high yield Kernel Screening Assay
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Products ready for registration
• Nigeria, Senegal, Burkina
Faso and Kenya
Products under field testing
• Zambia
Products under development
• Ghana, Tanzania and
Mozambique
Products development to start
• Mali, The Gambia, Uganda,
Ethiopia, Rwanda, Burundi
and South Sudan
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Biocontrol
Product: Aflasafe (Mixture
of 4 native atoxigenic strains)
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Farmers treating maize and groundnut fields with Aflasafe in Nigeria
MAIZE: Aflatoxin reduction (%)
Stage 2009 2010 2011 2012
Harvest 82 94 83 93
Storage 92 93 x x
PEANUT: Aflatoxin reduction (%)
Stage 2009 2010 2011
Harvest - 95 82
Storage 100 80 x
Results from 482
on-farm trials
71% and 52% carry-over of
inoculum 1 & 2 years after
application
Biocontrol x Resistance
Experimental variety
At harvest
Control Aflasafe
RSYN2-Y 19.6 1.7
RSYN3-W 6.9 1.8
SYN3-Y 18.4 1.7
TZB-SR (susc.) 57.5 4.7
After poor storage
Control Aflasafe
462 44
627 38
387 19
1152 163
Combining management tactics increases extent of aflatoxin reduction
Aflatoxin (ppb) in Low-Aflatoxin Maize Lines With and Without Aflasafe Treatment
www.iita.org A member of CGIAR consortium
www.iita.org A member of CGIAR consortium
Advocacy and Policies
• National and regionally harmonized standards in foods and feeds
• Intra-regional trade of safe food
• Enhanced capacity of regulators
• Alternative uses
• Disposal of contaminated material
• Regionally harmonized protocols for biopesticides registration
• Inclusion of aflatoxin in nutrition and health policies
• Aflatoxin alert system in Africa
• Critical role of PACA and RECs
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Markets
Doreo Partner analysis
Poultry industry
Export-oriented aggregators
Food processors
Large commercial farmers
Smallholder farmers
Market based
• Poultry feed
• Premium food
market
• Export
AgResults (Incentive-
cum-market based)
ma
rket
dem
an
d f
or
Afl
as
afe
• 60% maize consumed by farmers
• 40% sold in the market
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Challenges
• Aflatoxin is a hidden problem
• Chemical analysis required
• Awareness is low
• Long incubation for expression of health impacts
• Regulations either non-existent or poorly enforced
• Market does not usually discriminate
• Demonstration of product value
• Lack of biopesticide manufacturers
The value of a technology on the shelf is as much as the cost of the space it occupies on the shelf.
Must translate knowledge into usable products and practices to benefit people
But……
Pilot Implementation
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• Value chain-centric: Farmers’ and other value chain participants’ interest as the foundation of the action
• Action-oriented: Using practical methods to actively solve problems, not just talking about ideas, plans, or theories
• Innovation platform: problem solving by participants working regularly together to address common issues and challenges.
Innovation Platform
• Platform meetings with leadership and members of Poultry Association of Nigeria, feed manufacturers, maize aggregators, aflasafe farmers, vet professionals and regulators
• Poultry farmers to buy all aflasafe maize at a negotiated premium
• Agriculture ministry to fund NAFDAC to set up aflatoxin testing facilities in each state
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Babban Gona Pilot
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• Farmers’ cooperative with professional management
• Credit, inputs and technical services
• Yield enhancing practices
• Aflatoxin awareness
• Aflasafe use
• Aflatoxin testing – 100% met standard
• Incentive for meeting aflatoxin standard
• Warehousing
• Output marketing – linking to market
• Return profit after sale
• Farmers keep part of the harvest for family use
G-20 AgResults Aflasafe
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• Pull mechanism – Aflasafe is one of the first three pilots
• Provides incentives after demonstrating adoption
• Private sector driven, but focused on smallholder groups
• Implementers provide credit, inputs and technical services to increase yield
• Aflasafe purchased at cost to improve quality
• Maize tested for aflasafe strains; if present in large frequency, the implementers incentivized with $18.75/ton maize
• Implementers negotiate maize sale at premium
• Project provides aflatoxin awareness, training of implementers, and identifies potential market linkages
• Target: 260,000 ha in 4 years
Award-winning Research
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Charity Mutegi received the Norman Borlaug Award for Field
Research and Application from the World Food Prize Foundation.
Charity received this award in recognition for her work in various
facets of aflatoxin management in Kenya, which included
awareness raising, capacity building, establishing risk assessment
data, and extending and potential deployment of a biological
control product called aflasafe, for managing aflatoxin.
Summary
www.iita.org A member of CGIAR consortium
• Impact of aflatoxins have several development dimensions: – post-harvest losses, nutrition,
health, crops, livestock, fish, trade, markets, policies, institutions and politics
• Reduction of aflatoxin will improve human health, increase farm income, improve profitability of animal industries, increase regional and international trade, and reputation of African products in global markets
Ibadan IITA
Tucson
USDA/ARS IITA, USDA, AATF & Doreo have Teamed up to Bring
Aflatoxin Prevention to Africa
Made Possible by Many National Partners in Ministries, Industry, and on the Farm
Nigeria
For more information about aflatoxin biocontrol for Africa, check out: www.aflasafe.com
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Experimental varieties
Aflatoxin reduction (%)
Resistance alone
Biocontrol alone
Resistance + Biocontrol
RSYN2-Y 66 (60) 91 (90) 97 (96)
RSYN3-W 88 (46) 74 (94) 97 (97)
SYN3-Y 68 (66) 91 (95) 97 (98)
TZB-SR (Susc.) 58 (1152) ppb 92 (86)
% Reduction in experimental varieties compared to susceptible variety (TZB-SR) under natural conditions
% Reduction in varieties with biocontrol compared to susceptible variety (TZB-SR) under natural conditions
% Reduction in biocontrol treated plots compared to control plots of the same experimental variety
% Reduction in varieties with biocontrol compared to susceptible variety (TZB-SR) under natural conditions
% Reduction in biocontrol treated plots compared to untreated plots of the same variety
Synergistic Effect of Resistance and
Biocontrol in Reducing Aflatoxins at Harvest and after poor storage
Biocontrol x Resistance
Experimental variety
At harvest
Control Aflasafe
RSYN2-Y 19.6 1.7
RSYN3-W 6.9 1.8
SYN3-Y 18.4 1.7
TZB-SR (susc.) 57.5 4.7
After poor storage
Control Aflasafe
462 44
627 38
387 19
1152 163
Combining management tactics increases extent of aflatoxin reduction
Aflatoxin (ppb) in Low-Aflatoxin Maize Lines With and Without Aflasafe Treatment
www.iita.org A member of CGIAR consortium Mycored Europe, 28 May, 2013