Aflatoxins agriculture and technology solutions available for abating the aflatoxin challenge

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


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


• 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

http://www.aspergillusflavus.org/images/cycle.jpg

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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.


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)

EC 2007

Aflatoxin and Trade


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

www.iita.org www.iita.org A member of CGIAR consortium

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


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

(kg

/ha)

Less toxin – high yield Kernel Screening Assay

www.iita.org

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


Biocontrol

Product: Aflasafe (Mixture

of 4 native atoxigenic strains)

www.iita.org

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


Aflasafe Plan & Plant

Capacity: 5 tons/hour

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



Training & Use by Farmers


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


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

rke

t d

em

an

d f

or

Afl

as

afe

• 60% maize consumed by farmers

• 40% sold in the market


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


• 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


Babban Gona Pilot


• 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


• 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


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


• 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

http://www.entwicklung.at/en/

www.iita.org

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

Aflatoxins agriculture and technology solutions available for abating the aflatoxin challenge

Science

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