The document discusses evaluating the combined effect of applying Aflasafe, a biocontrol product, and using aflatoxin resistant maize hybrids to reduce aflatoxin levels. Field trials were conducted in Nigeria with different maize varieties and Aflasafe application. The results showed that combining Aflasafe application and aflatoxin resistant varieties reduced aflatoxin levels by more than 90% compared to the susceptible variety without Aflasafe treatment. The study demonstrates the synergistic effects of integrating host resistance with biological control methods.

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Synergistic Effect of
Resistant Maize Synthetics
and Aflasafe Application
Joseph Atehnkeng
For the team

2. Development of aflatoxin-
resistant varieties
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Breeding may target:
• Direct selection for resistance to fungus and
aflatoxin accumulation
• Indirect selection for resistance or tolerance to
biotic and abiotic stresses.
• Selection for morphological traits such as ear,
kernel, and husk characteristics that impede
or delay fungal introduction or growth.

3. Technology-implementation
challenges
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• Accumulation of aflatoxins in maize occurs following a complex
series of interactions
• Among maize
• The environment
• The pathogen
• insects
• Crop-management practices.
• Selection must be done simultaneously for multiple stresses in
order to combine drought and heat tolerance, resistance to
insects (especially ear-feeding insects), and resistance to the
pathogen.
• These stress tolerances must be combined with improved
agronomic performance in new maize varieties for adoption of
aflatoxin-resistant cultivars to occur, as farmers will not grow low-
yielding varieties regardless of aflatoxin resistance.

4. 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)
Aflatoxin(ppb)
Grainyield(kg/ha)
Less Aflatoxin Susceptible, High-
Yielding Yellow Maize Hybrids
Less toxin – high yield

5. Product: Aflasafe
Mixture of 4 native atoxigenic strains
Nigeria

6. How Does aflasafe Work?
Broadcast
@ 10 kg/ha 2-3 weeks
before flowering
Sporulation on moist soil
Spores
Insects
Aflasafe in 5 kg boxes
3-20
days
Wind
Soil
colonization
30-33 grains m-2
Fungal
network in
killed grain

7. 75
94
100
03
39
73
27
0
20
40
60
80
100
120
<4 <10 <20 >20
Nestlé/EU WFP/Nigeria US Unsafe
Maximum allowable aflatoxin level (ng g-1)
Farmers'fields(%)
Treated
Control
Different Levels of aflatoxin
in AflaSafe™ treated and
untreated fields at harvest

8. Objective
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• To evaluate the combined effect of
aflasafeTM and aflatoxin resistant
hybrid to reduce aflatoxin reduction.

9. Field Layout
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10 x 7.5 m
Alley Alley Alley Alley Alley Alley
10 x 7.5 m
Treated area with aflasafe
Untreated area
•2010 = 3 location
•2011 = 9 locations
• Maize varieties
• AFLTOXINRSYN3-W
• AFLTOXINRSYN2-Y
• AFLTOXINRSYN2-Y
•TZB-SR
• Replicated 6 times
• Aflasafe applied at 40
DAP
A t Maturity
• 25 maize cobs collected
from each plots at harvest
• Analyzed for aflatoxin

10. 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
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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

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Aflasafe and Cultivar Interactions
Experimental
variety
Without
Aflasafe
With
Aflasafe
Reduction
(%)
RSYN2-Y 18 (aA) 0 (aB) 100 (a)
RSYN3-W 57 (bA) 2 (bB) 96 (b)
SYN3-Y 36 (aA) 0 (aB) 100 (a)
TZB-SR (susc.) 67 (bA) 3 (bB) 96 (b)
Aflatoxin (ppb) in Low-Aflatoxin Maize Lines With
and Without Aflasafe Treatment in Shika
Means within a column with same lowercase letter, and means of treated-control pairs
within a row with the same uppercase letter are not significantly different; P < 0.0001
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13. Conclusion
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A combination of the two technologies
reduces aflatoxins by more than 90 %

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Thank you

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Background
• Pre-harvest host resistance
• Though commercial varieties are not yet available
effort are in progress

16. Experiment layout
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•In Kaduna State
• In 2010 = 3 locations
• In 2011 = 9 locations
• Maize varieties
• AFLTOXINRSYN3-W
• AFLTOXINRSYN2-Y
• AFLTOXINRSYN2-Y
• TZB-SR

17. Generation of resistant
germplasm
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Methods to achieve resistance to A. flavus and
aflatoxin accumulation include:
• Prevention of fungal infection of maize, which is
especially important under stressed environmental
conditions
• Prevention of subsequent growth of the fungus
once infection has occurred
• Inhibition of aflatoxin production following
infection
• Degradation of aflatoxins by the plant or fungus.