Aflatoxin Mitigation in Zambia and Malawi

S.M.C., Njoroge, K. Kanenga, J. Maruwo, E. Musukwa, N. Machinjiri,

W. Sinkala, M. Siambi, F. Waliyar, and E. Monyo

Objectives

• Quantify the incidence of aflatoxin in

groundnut (along the value chain)

• Investigate and promote integrated

management approaches against aflatoxin

contamination and train farmers in integrated

management options

AFB1 contamination in peanut butter

• Chipata, Katete, Petauke, and Lusaka

• 954 containers, from 25 brands tested

• A sample = 6 containers of a single brand,

manufacturing date, and from the same shop

• Each container was assayed 5 times, ELISA

• Geometric means calculated (log transformed)

• 9, 12, and 8 brands were repeatedly tested

within 1 year, across 2 years, and in all 3 years,

respectively

• 0% of brands repeatedly tested across 3 years

had AFB1

• 8% of brands tested repeatedly across 2 years

had AFB1 ≤ 20 ppb

• 44% of brands tested in just one year had AFB1

≤ 20 ppb

• Zambia, Zimbabwe, Malawi, South Africa

Other countries

• Mpunga et al. (2014)- Zimbabwe- 11 samples:

91% contaminated, mean 75 ppb

• Matumba et al. (2014)-Malawi- 14 samples:

local 34 to 116 ppb vs imported 0.2 to 4.3 ppb

• Ndungu et al. (2013)- Kenya- 22 samples: mean

318 ppb, ranged 0 to 2,377 ppb

• Schwartzbord & Brown (2015)- Haiti- 2 years-

56 samples: 94% > 20 ppb

• Developing countries

Other countries

• Kumagai et al. (2008)- Japan- 21 samples both

imported and local- 50% were contaminated,

highest 2.59 ppb

• Mortimer et al. (1987)- UK- 129 samples, 6.2%

exceeded 10 ppb, 8% had 2.5 to 10 ppb, rest non-

detectable

• Developed countries

• Over 100 countries have set standards

AFB1 in grain and powder

• 201 grain samples and 39 milled powder

• Chipata, Katete, Petauke, Lusaka, Kitwe,

Ndola, Kabwe

• 1 kg sample, analyzed 6 times

• 77% of 39 powder samples > 20 ppb AFB1

• 45% of 201 grain samples > 20 ppb AFB1

• No documented successful interventions in

informal markets

Regional

• Kamika et al. (2014)-Congo, South Africa,

40 grain samples: Kinshasa > Pretoria, 40% and

10%, respectively had > 20 ppb

• Mupunga et al. (2015)-Zimbabwe, 18 grain

samples: 3 had detectable aflatoxin, 7 to 620 ppb

• Ndungu et al. (2013)-Kenya, 82 grain samples:

43% > 10 ppb

Survey pictorial

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Feb 17 Feb 24 Mar 03 Mar 10 Mar 17 Mar 24 Mar 31 Apr 07 Apr 14 Apr 21 Apr 28

%VWC Chitedze_Soilmoisture_1234

VWCA VWCB VWCC VWCD

Rainfall and soil moisture 2013/2014

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Jan 20 Jan 27 Feb 03 Feb 10 Feb 17 Feb 24 Mar 03 Mar 10 Mar 17

%VWC Chitedze_Soilmoisture_E,F,G,H

VWCA VWCB VWCC VWCD

Rainfall and soil moisture 2014/2015

Pre- and postharvest interventions

• 36 farmers in 64 villages, from 4 districts

• Farmer training centre’s

- Time of planting, Manure, Water-management

• Onstation (Msekera, Chitedze, Mwimba, Ngabu,

and Chitala)

-Liming, water-management

Tied Ridges

Mulching

Research question: Can we reduce aflatoxin contamination

through water management technologies?

Tied-ridges (dyking), mulching

Soil moisture data logger

Mulch Bare soil

Soil moisture probe

Water management

Survey- AFB1 contamination (ppb)

PET NYI CHI MAM

0-4 21 15 43 38

>4 to 20 41 50 32 31

>20 to 100 30 23 23 26

>100 to 1000 7 9 5 -

>1000 1 3 1 -

N 100 100 104 95

Maximum 3,258 4,980 1,077 69

Arithmetic mean 0.9 1.1 0.8 0.7

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Time1 Time2 Time3 Mulch Tied ridges Control 2.5 T/Ha 3.5 T/Ha Control

Afl

ato

xin

B1

co

nta

min

ati

on

(L

og

pp

b)

Treatments

Chipata district, 2013/2014

Post-harvest, Chitedze, 2014/2015

Red: >20 ppb

Black: >10 ≤ 20 ppb

Orange: ≥4 ≤10 ppb

Green: < 4 ppb

Conclusions

• Integrated approach works

• Upscaling-TOP, Manure, Drying

techniques, Sorting

• Climate smart and enhance yield

• Market incentives needed

• Interventions needed- Peanut butter,

informal markets

• Beyond standards

ICRISAT is a member of the CGIAR Consortium