testing of a bioherbiode technology for Striga control

A member of CGIAR consortium www.iita.org
Progress in the development and field testing of a
bioherbicide technology for Striga control
Abuelgasim Elzein
15 June 2015, Contract Review Seminar, IITA HQ, Ibadan

Striga is an obligate root parasite
Host plants:
Cereals (Sorghum, Maize, Millet Rice and
Sugar cane)
Cowpea
Infested field with Striga hermonthica in Nigeria
(M’Boob 1989; Sauerborn 1991; Ejeta 2007)
Agricultural significance:
• Major biological constraint to cereal
production in Sub-Saharan Africa
• can cause total crop loss especially under
low soil fertility, drought, land degradation
and continuous cereal monocultures
• causing negative impacts on the food
security, incomes and nutrition of milions of
subsistance farmers

Attachement
to host roots
Host plant
Striga seed
Germ tube
Host root (Sorghum)
Parasitic nature of Striga
Withdraw water, mineral nutrients and carbohydrates: causing drought stress, wilting,
drying and stunted growth of the host

Actually: 21 million ha, Potentially: 44 million ha.
4.1 million tonnes of grain lost annually (Sauerborn, 1991)
Annual yield losses in savanna region = $7 billion (Ejeta, 2007)
Estimated infestation of Striga spp. in Africa
Sorghum infested field with Striga in Gadarief, Sudan
Geographical distribution of Striga in
Africa (Ejeta, 2007)

Survival strategy of obligate Striga
Seed capsule (500 - 1000 seeds/capsule)
1. High seed production rate (20.000
- 200.000 and more seeds per
plant)
2. Longevity of seeds (>10 years)
(Parker & Riches, 1993)
• Control is extremely difficult
• Single control methods are not
sufficient to control Striga
effectively and economically
• Integrated control approach is
the ideal strategy
• Biological control can represent
an important component in the
Integrated control approach
Striga hermonthica

Protocol
1. Survey the diseased weed for pathogens;
2. Isolation;
3. Identification and classification;
4. Inoculum production;
5. Screening for efficacy (pathogenicity testing);
6. Host specificity and safety testing;
7. Inoculum mass production;
8. Formulation and delivery to target weed
9. Field efficacy and performance (field testing);
10. Registration
11. Commercialization.
1
2, 3
4, 7
88
• Bioherbicide (Mycohericide) approach: refers to pathogens (fungus)
used as weed biocontrol agents.
• it is environmentally friendly and ecologically sound,
• can be specific to the target host, and effective
• and has the potential to be economically viable
Biocontrol of Striga with pathogens – Bioherbicide
approach

S. asiatica
Fusarium oxysporum f.sp. strigae (Fos)
Foxy 2 & PSM197S. hermonthica
Fos advantages
It attacks Striga in all developmental stages including seeds,
Host specific to Striga, safe and does not produce toxins
 It can be easily mass-produced using agricultural by-product
 It can be formulated into Pesta granules or delivered as seed treatments
Biocontrol of Striga with pathogens – Bioherbicide
approach

Seed treatment delivery forStriga bioherbicides
 Minimizing the inoculum amount.
 Establishing the biological control agent in the potential
infection zone of the Striga, the host root.
 Offering simple, easy and economical delivery system
Striga attachment
Striga seed
Germ tube
Host root
Biocontrol delivery system
Coated uncoated
Protocols are developed and optimized
using Arabic gum as coating material
Chlamydospores
Elzein, A., J. Kroschel and V. Leth (2006): Biocontrol
Science and Technology 16 (1) 3-26.

Seed treatment: host root colonization by BC Fos
Control Foxy2 coated seed
Foxy 2 hyphae colonize and follow the root down into the soil
LM of Sorghum roots Longitudinal section (2 weeks after germination)
Multiplication of Fxoy 2 in the surrounding soil and rhizosphere
sorghum root
hyphae
hyphae
100µm
Ndambi, B., Cadisch, G., Elzein, A., Heller, A., (2011). Biological Control 58, 149–159; Elzein, A., A. Heller, B. Ndambi, M. De Mol, J. Kroschel and G. Cadisch (2010):
Biological Control 53, 249-257; Elzein, A., J. Kroschel and V. Leth (2006): Biocontrol Science and Technology 16 (1) 3-26.
2mm
2mm
SR
Sorghum root Sorghum root
Control- Healthy Striga seedlings
Foxy2-trated-root - Diseased
Striga seedlings
Later stage of diseased
Striga seedlings
Foxy-treated seedsControl

Striga biocontrol technology in IITA
The Striga biocontrol technology is a component of ISMA (Integrated Striga
Management in Africa) project, funded by Bill & Melinda Gates Foundation
(BMGF)
Objective:
– To validate efficacy of Striga biocontrol technology (Fusarium
oxysporum f.sp. strigae) across different agro-ecological zones
(AEZs) in Nigeria whilst also:
– confirming biosafety,
– assessing cost benefit,
– increasing awareness,
– developing molecular detection and monitoring tools,
– Integrating with other ISMA complementary technologies

Progress on Striga biocontrol technology in IITA
Key Milestones:
1. Biosafety
• Host specificity
• Mycotoxins production
2. Efficacy field validation
3. Socio-economic analysis and cost-benefit
4. Compatibility with pesticides and other technologies
5. Increase awareness
6. Towards registration
7. Molecular detection tools
8. Future plan
Diseased Striga plants

Partnerships

Biosafety – host specificity
• Three host specificity trials have been carried out under field and screen house
conditions in collaboration with IAR-ABU and partnership with NPQS
• Test crops: 25 crops selected in consultation and approval of NPQS based on
1. Crops related to the Striga host crop maize (maize, sorghum, rice, pearl millet, finger millet,
wheat),
2. Crops with high susceptibility to Fusarium oxysporum diseases (potato, tomato, pepper,
egg plant, okra, cotton, pigeon pea, soybeans, water melon, sesame and onion )
3. Economically important cultivated crops (cowpea, ground nut, cassava & yam),
4. Other crops commonly intercropped / and or rotated in the farmers fields (cocoyam,
pumpkin, sweet potato and Desmodium sp.)
Objective: To ensure the safety of Striga biocontrol agents to non-host plants and
demonstrate to regulatory authorities and stakeholders that the BC agents do not
cause disease on any other plant than Striga and safe to use.

Biosafety - host specificity
• Bioherbicide: Pesta granular formulation – prepared by University of Hohenheim
• Pesta Granules: inoculums of the strains were encapsulated in a matrix of durum wheat-
flour, kaolin, and sucrose
• Dose: 1 g of Pesta granules to each hole (or pot) at a concentration of 1x105 cfu g-1 which
represents a 10 fold increase above intended field application rates via seed coating.
Pesta with Foxy2 Pesta without BCA as control

Biocontrol Team inspecting the crops
NPQS inpection team at IITA Kano
Inspection of host specificity trials

The effect of BC agents on performance of crops with high susceptibility
to Fusarium oxysporum diseases
§ Plant vigour rating on a scale of 0-5, where 0 = (the most vigorous and healthy growth), and 5 = (the least vigorous growth).
Crop/treatment Germination
(%)
Plant height
(cm)
Plant
vigour§
Chlorophyll
content (SPAD)‡
Plant shoot fresh
weight (g)
Plant shoot
dry weight (g)
Okra
Foxy2 66.7ab 41.5a 0.6a 41.0a 18.0a 8.1a
PSM197 75.0a 45.1a 0.8a 42.1a 40.7a 5.2b
Control + Pesta 41.7b 42.8a 1.3a 44.2a 12.3a 6.1b
Control 58.4ab 44.9a 0.9a 41.7a 13.4a 5.8b
LSD (0.05) 24.1 8.3 0.9 3.3 41.7 1.6
Onion
Foxy2 100.0 28.8a 1.4a 51.9a 19.2a 12.2a
PSM197 100.0 31.0a 1.3a 47.7a 23.1a 13.7a
Control + Pesta 100.0 30.7a 1.4a 42.8a 18.4a 10.3a
Control 100.0 27.6a 1.6a 38.4a 17.7a 11.1a
LSD (0.05) - 4.2 1.0 13.8 10.5 6.7
Soya bean
Foxy2 75.0b 59.6a 0.8a 40.2a 25.9a 5.8b
PSM197 75.0b 56.8a 0.6a 42.6a 22.7a 9.1a
Control + Pesta 100.0a 63.3a 1.3a 41.3a 20.9a 7.0b
Control 58.4b 57.9a 1.5a 43.0a 15.0a 6.5b
LSD (0.05) 22.8 7.8 1.1 4.7 27.7 1.8
Tomato
Foxy2 100.0 27.6a 1.4ab 40.9a 8.6a 4.7a
PSM197 100.0 28.6a 1.0b 32.8b 9.8a 3.5a
Control + Pesta 100.0 31.1a 1.9a 30.8b 8.4a 3.8a
Control 100.0 27.9a 2.0a 30.8b 7.7a 4.9a
LSD (0.05) - 3.5 0.8 5.9 3.3 1.4
Results: None of the tested crop plants showed any infection by the BC agents, and no
negative effects on growth was measured or visual losses to plant health was recorded,
i.e. inoculation with the BC agents did not cause any delay in emergence, ...

Okra Cowpea
Groundnut Rice
PSM197 Foxy2 Pesta C Control

Biosafety – mycotoxins
• Many species of Fusarium produce a range of phytotoxic compounds, such as
fumonisin, moniliformin and others and some of these compounds have a marked
toxic effects on humans, animals and plants (Nelson et al. 1993; Nelson et al. 1994)
• Assessment of production of mycotoxins by BC agents was carried out in
collaboration with the University of Stellenbosch (SUN) in South Africa.
• Mycotoxin production by BC agents was analyzed by SUN (Prof A Viljoen), and
verified under the inundative inoculations applied to cereal seed as influenced by the
soil microbiota.
Objective: to assess of biosafety of Striga BC agents based on production of mycotoxins

Biosafety - mycotoxins
Fumonisin:
Positive
controls
12 Fos samples Water
control
Tricothecenes:
12 Fos
samples
Positive
Controls
Water control
Genes responsible for of fumonisin or
trichothecene production absent
No production of fumonisin or tricothecenes
by Striga biocontrol agents
By Prof A Viljoen, University of
Stellebosch, SA
Gel electrophoresis of fumonisin or tricothecenes
gene detection in Fusarium oxysporum by PCR

• None of the 25 tested crop plants showed any infection by the Striga biocontrol
both in the field and screen houses.
– No negative effects on growth was measured
– No disease produced on plants other than Striga by the biocontrol agents.
• The results showed that Striga BC agents does not produce any known mycotoxins
(e.g. Fumonisin & Tricothecenes) that pose a threat to human health or harmful
effects on crops or environment.
• The Nigerian regulatory authorities (NPQS, NAFDAC) and other stakeholders
satisfied and increased confidence that the technology is safe to use
Biosafety - Summary
Cassava Coco yam
PSM197 Foxy2 Pesta C ControlPSM197 Foxy2 Pesta C Control

Biocontrol field validation
Objective :
– Field validation of the efficacy of biocontrol technology Fusarium oxysporum f.
sp. strigae (Fos) across different agro-ecological zones (AEZs) where maize
based farming systems predominate in Nigeria

Biocontrol agent: F. oxysporum f.sp. strigae (Foxy2)
Maize: Striga resistant and susceptible maize varieties recommended by Dr. Menkir were
used
Biocontrol (bioherbicide) product:
Professional inoculum production and seed coating
using Arabic Gum performed at UofH & SUET Germany IITA HQ for the 1st time
Field trials sets:
1. On farm farmer-mamaged trials
2. Research trials (on farm & on station)

• During the last 3 years, a series of extensive field validation trials were
conducted
– on farm across different AEZs including Northern Guinea Savanna (NGS) and
Sudan Savanna (SS) in Kano and Bauchi states, to comprehensively validate the
control efficacy of the BC Fos (isolate Foxy2) against Striga.
– on station in Mokwa and Zaria under artificialStriga infestation
ISMA (BC) project locations in Nigeria

Professional coating of maize seeds with BC inoculums,
performed at IITA HQ for the 1st time
Seed coating machine used (back view) Seed coating machine used (front view)
Maize seeds in the of the coating machine before coating Maize seeds in the of the coating machine during coating
untreated control (yellow); maize seeds film-coated with BC (blue)
Small seed coating machine purchased with support from our DG Dr.
Sanginga, and in partnership with Dr Menkir, and used to coat maize
seeds with Biocontrol & imazapyr & MSM herbicides on IR
Chlamydospores
Dried Chlamydospores
Fungal inoculum
Benefits
1. BC inoculum mass production and seed coating
technology established at IITA,
2. logistic and technical costs of performing seed
coating outside Nigeria will be saved,
3. other relevant research at IITA will be facilitated and
strengthened using this unit (e.g IR maize coating
with imazapyr & MSM),
4. capacity in this innovative technology will be built.

Biocontrol efficacy in on-farm farmer’s trials
(47 locations, 27 with resistant, 20 with susceptible, 2014)
Maize grain yield (kg ha-1)
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Resistant Susceptible
Maizegraimyield(kgha-1)
Farmer's choice Untreated control Biocontrol
c
LSD (0.05) = 165 (***)
b
a
a
LSD (0.05) = 229 (***)
b
c
108%
101%
45%

Biocontrol efficacy in on-farm trials
Striga damage symptoms on maize plants
# Striga damage rating on a scale of 1-9, where 1 = no damage symptoms and 9 = severe damage symptoms due to Striga
(Berner et al., 1997)
0
1
2
3
4
5
6
7
8
Strigadamagerating# Farmer's choice Untreated control Biocontrol
b
a
c
a
b
c
LSD (0.05) = 0.3 (***) LSD (0.05) = 0.36 (***)

Striga emergence
0
30
60
90
120
150
180
210
240
270
300
330
EmergedStrigaplants(No.10m-2)
b
b
b
LSD (0.05) = 68 (***) LSD (0.05) = 84 (***)
a
b
a

Diseased (%) emerged Striga plants
0
10
20
30
40
50
60
70
80
90
100
DiseasedStrigaplants(%)
b
c
LSD (0.05) = 5.4 (***) LSD (0.05) = 8.1 (***)
a
b
a
c

Reduction (%) in emerged healthyStriga compared to BC application
96
93
80
72
0
10
20
30
40
50
60
70
80
90
100
Farmer's choice Untreated control

BC efficacy under SS AEZ on-farm
95TZE COMP4 C3 F2TZE Comp.5-W C7
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Farmer's choice Untreated Control Biocontrol
c
LSD (0.05) = 245 (***) a
b
a
LSD (0.05) = 282 (***)
c
b
113%
113%
51%

BC efficacy under NGS AEZ on farm
TZL COMP1SYNY-1F2
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Maizegraimyield(kgha-1) Farmer's choice Untreated Control Biocontrol
c
LSD (0.05) = 220 (***)
b
a
c
b
a
LSD (0.05) = 252 (***)
102%
88%
38%
3883-1

BC efficacy across individual farmer trials under SS
AEZ
Maize grain yield increase (kg ha-1)
# Yield increase per individual field are significantly different from controls
This indicates that the BC efficacy is very consistent regardless of the maize variety
-500
0
500
1000
1500
2000
2500
3000
3500
4000
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
Farmer choice Untreated Control Biocontrol
Increaseinmaizegrainyield(kgha-1)
Farmer fields
Mean yield increase = 1718 kg/haLSD (0.05) = 245 (***) LSD (0.05) = 282 (***)Mean yield increase = 2107 kg/ha
Resistant (TZE Comp.5-W C7) Susceptible (95TZE COMP4 C3 F2)

BC efficacy across individual farmer trials under NGS
AEZ
Maize grain yield increase (kg ha-1)
Resistant (TZL COMP1SYNY-1F2) Susceptible (3883-1)
# Yield increase per individual field are significantly different from controls
This indicates that the BC efficacy is very consistent regardless of the maize variety
-500
0
500
1000
1500
2000
2500
3000
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Farmer choice Untreated Control Biocontrol
Increaseinmaizegrainyield(kgha-1)
Farmer fields
Mean yield increase = 1703 kg/haLSD (0.05) = 220 (***) LSD (0.05) = 252 (***)Mean yield increase = 1835 kg/ha

Farmer’s saved seeds control, yellowish and showing Striga
damage symptoms and reduction in height
BC + Resistant variety, deep green and no visible Striga
damage symptoms
On farm trial (farmer evaluation trial) at Dass in Bauchi

Farmer’s local maize plants sown at the same time under a typical traditional farming practice; stunted, yellowish & drying due to Striga damage
Resistant maize plants + BC + fertilizer (ISMA package), deep green, vigorous with excellent performance and no Striga damage
Fig. 5b. Effect of the bioherbicide Fos on Striga incidences and maize performance on farmer field in Bauchi in Nigeria:

Biocontrol efficacy on-farm research trials
(3 locations in SS)
0
500
1000
1500
2000
2500
3000
3500
4000
Untreated control Control + AG Biocontrol
bc c
a
b
LSD (0.05) = 270 (***)
d
e
85%
42%

Biocontrol on-farm research field trial at Gar, Alkaleri, Bauchi
BC+Resistant
Control SusceptibleControl Resistant
Traditional farmer maize/sorghum
19 striga/m2 84% Red.5.3 striga/m2 45% Red.
2.9 striga/m2
>100 Striga/m2

• In conclusion, the results of field validation trials of two successive seasons (2013 &
2014) showed that the application of biocontrol in combination with both Striga
resistant and susceptible varieties significantly
• reduced Striga incidences and damage symptoms on maize plants, and
• improved grain yield on average by 82% (1600 kg/ha) in a consistent manner, compared to
farmer’s choice (local maize variety), across different AEZs in Nigeria
• BC showed also compatibility and additive effect with the resistant variety on-farm.
• BC contributed to the grain yield increase of the resistant variety by 57% on-farm,
raising the grain yield increases to 104%, compared to farmer’s choice.
• Hence, the advantage of combing BC with the resistant maize and deliver it in a
package to farmers using the same input pathway will
– reduce transaction and application costs,
– increase the grain yield
– enhance further the cost-benefit of the two technologies
Summary – Biocontrol efficacy validation

Cost-benefit of BC technology
• Socio-economic and cost benefit analysis of BC was carried out in collaboration
with IITA Socio-economic unit (Dr. T. Abdoulaye), and performed by Mr. Bello
Hassan from ABU as a PhD study.
• We provided the relevant information about BC technology and associated costs,
and helped him to fill questionnaires from all farmers in Bauchi and Kano where BC
trials were established.
• The cost-benefit of biocontrol technology was determined based on:
– Actual Field data [field trials material (cost of maize seeds); supplies and operational
costs (land preparation, planting, weeding, fertilizers, fertilizers application, harvesting,
threshing, bagging, transportation etc.)];
– Yield data,
– Cost of biocontrol product,
– Surveys and interviews with farmers,
– Current market information (price of maize and transportation cost etc.)
Objective: to assess profitability of Striga biocontrol technology

BAUCHI State
Maize varieties
Means of variables FARMER VAR. RESISTANT
Resistant +
Biocontrol
Gross farm gate benefits
1 Average yield (kg/ha) 1,846.48 2,751.40 3,910.00
2 Price of maize (Naira/kg) 55.57 55.57 55.57
3 Gross farm gate benefits (N/ha) 102,608.84 152,895.30 217,278.70
4 Ground rent 2,642.86 2,642.86 2,642.86
5 Seed cost per hectare 1,184.40 4,000.00 6,703.14
6 NPK Cost per hectare 30,600.00 30,600.00 30,600.00
7 UREA cost per Hectare 9,314.29 9,314.29 9,314.29
8 Cost of land preparation per hectare 4,507.14 4,507.14 4,507.14
9 Cost of planting/ha 2,035.71 2,035.71 2,035.71
10 Weeding cost per hectare 3,928.57 3,928.57 3,928.57
11 Fertilizer application cost per hectare 3,928.57 3,928.57 3,928.57
12 Moulding cost per hectare 2,011.00 2,011.00 2,011.00
13 Cost of harvesting per hectare 8,620.38 12,780.00 18,196.00
14 Cost of handling per produce per ha 3,614.82 6,940.86 16,114.65
15 Cost of sacks/ha 1,680.72 2,488.70 3,533.99
16 Total variable cost(sum 4-15) 74,068.46 85,177.70 103,515.92
Net Benefit
17 Net benefit (N/ha) (3 - 13) 28,540.37 67,717.60 113,762.78
18 Benefit costs ratio (3/16) 1.39 1.80 2.10
19 Average rate of return % (ARR) 38.53 79.50 109.89
20 Change in net benefits between 39,177.22 46,045.18
two consecutive treatments (N/ha)
21 Change in total variable input costs 11,109.238 18,338.22
between two consecutive
treatments(N/ha)
22 Marginal rate of return (20/21) 3.53 2.51
Table 1:Partial budget for maize production comparing biocontrol technology and resistant varieties

Cost benefit of BC technology
Benefit cost ratio of Biocontrol & Resistant for Bauchi and Kano, 2014
BC technology is cost
effective;
Benefit cost ratio =
/ Total variable input
costs (N/ha)
1.39
1.8
2.1
1.38
1.74
2.1
0
0.5
1
1.5
2
2.5
Farmer's variety Resistant Resistant +
Biocontrol
Bauchi Kano
Benefitcostratio

Benefit cost ratio of Biocontrol & Susceptible for Bauchi and Kano, 2014
effective;
Benefit cost ratio =
/ Total variable input
costs (N/ha)
1.33
1.78
2.12
1.02
1.41
1.85
0
0.5
1
1.5
2
2.5
Farmer's variety Susceptible Susceptible +
Biocontrol
Bauchi Kano
Benefitcostratio

Cost benefit of BC technology and resistant
Net benefit (average Bauchi & Kano) for seasons 2013 & 2014 (NGN ha-1)
effective
when combined with the
resistant in season 2013
and 2014
0
20000
40000
60000
80000
100000
120000
Biocontrol
52570
92893
115907
29235
66034.5
109790
Season 2013 Season 2014
Netbenefit(NGN/ha)
NGN
276%
120%

Cost benefit of BC technology and susceptible
Net benefit (average Bauchi & Kano) for seasons 2013 & 2014 (NGN ha-1)
0
20000
40000
60000
80000
100000
120000
Biocontrol
34,186
77,628
106,455
12,998
50,159
92,296.5
Season 2013 Season 2014
Netbenefit(NGN/ha)
NGN
610%
213%
effective
when combined with the
susceptible in season
2013 and 2014

• The results of cost benefit analysis of two successive seasons (2013 & 2014)
showed that BC technology is cost effective with similar trend in Bauchi and Kano
states irrespective of the maize variety used
• With a average net benefit of 112,849 NGN/ha and 99,376 NGN/ha when combined
with the resistant and susceptible varieties, respectively is 4 times and 3 times
compared to 32248 NGN/ha for their farmer choice (local varieties)
• This cost benefit result strongly supports the positive obtained efficacy and yield
improvement results and strengthens the future of the BC technology.
Summary – cost benefit

Compatibility of BC with pesticides technology
Goal: aiming at dual co-controlling Striga and common fungal maize diseases with a single-
dose application of combined seed treatments of bicontrol, Imazapyr and certain
fungicides
• Collection of pesticides:
• Surveys with input suppliers, EAs & farmers about the type of pesticides routinely used
was conducted in Northern Nigeria where BC validation trials were established
• Samples of the most frequently used and delivered pesticides using seed treatments
were collected
• Compatibility of BCAs (Foxy2 & PSM197) with:
• Herbicides (Imazapyr, Metsulfuron Methyl (MSM) & Glyphosate);
• Fungicides with insecticide components (Apron Plus, Apron Star, Dress Force & Seedrex)
• Each with 4 to 6 levels of concentration was studied in vitro in laboratory
• The effects of pesticides on mycelial radial growth (cm) and sporulation BCAs were
evaluated on Potato Dextrose Agar (PDA) solid medium
Objective: to ensure that the herbicides imazapyr (IR) and certain fungicides can be
co-treated onto maize seeds without adverse effects on BCAs and vice versa
Is being carried out in collaboration and support of Dr. Minker

Compatibility of BC with imazapyr herbicides
Effect of imazapyr on mycelial growth and sporulation of biocontrol agents
0.0 g/L 0.5 g/L 1 g/L 2 g/L
Imazapyr concentration
Foxy2 PSM197
Mycelial growth (Ø cm) Conidia ml-1 (x106) Mycelial growth (Ø cm) Conidia ml-1 (x106)
0.0 g/L 4.1 a 3.8 a 3.7 ab 2.5 a
0.5 g/L 4.1 a 3.1 a 4.0 a 3.1 a
1 g/L 4.1 a 3.3 a 3.7 ab 2.7 a
2 g/L 3.9 a 3.7 a 3.5 b 3.4 a
LSD (0.05) 0.2 1.8 0.4 1.1
Application rate of imazapyr for Striga control in maize = (0.00037 g/seed)
• Both BCAs (Foxy2 & PSM197 ) showed excellent compatibility with Imazapyr (IR)
even at the highest tested concentration which is far higher (37 times) than the
recommended application dose. I.e the mycelial radial growth and sporulation of the two
isolates were not negatively affected,
• Both BCAs (Foxy2 & PSM197 ) showed excellent compatibility with Metsulfuron Methyl
(MSM) and Glyphosate herbicides
• Excellent to good compatibility with the seed treatment fungicides: Dress force, Apron Plus &
Pron Star, Seedrex.

Compatibility with imazapyr herbicide
• Doses and complementary seed coating protocols for the 2 compatible technologies
(BC & Imazapyr herbicide) have been developed
• IR maize seeds were successfully coated with a single-dose seed treatment of BCA
inoculums and imazapyr by partner in Germany using professional seed coating and
Arabic Gum as adhesive
• The IR maize seeds were uniformly coated and dust-free and with a concentration of 1.2x104
CFU of fungal inoculums and 0.00084 g of imazapyr per coated maize seed
Coated with BCCoated with BC + Imaza.Untreated control

Combined efficacy of biocontrol and imazapyr
Objective: to evaluate the combined control efficacy of biocontrol Fos and imazapyr
herbicide on Striga control and crop yield improvement, that delivered in a single-
dose application of seed treatment.
• IR maize seeds were coated with a single-dose application of combined seed
treatments of BC inoculums and imazapyr using professional seed coating
technology and Arabic Gum performed at IITA HQ in Ibadan
• The combined control efficacy of BC and imazapyr on Striga control and
improvement of IR maize performance was evaluated under artificial Striga
infestation in on station field trials.

Biocontrol + imazapyr
• inhibited Striga emergence,
• showed significantly very less Striga damage symptoms, compared to untreated controls
• All IR treatments showed significant grain yield increase compared to susceptible control,
• not grain yield improvement was recorded compared to untreated IR controls , but also ...
Combined control efficacy of biocontrol and imazapyr on Striga control and maize
performance evaluated under artificial infestation in Mokwa in Nigeria in 2014
† AG = Arabic Gum; ‡ number of Striga plants counted in 10 m2. * Significant at p<0.05; ** Significant at p<0.01; *** Significant at p<0.001;
Treatment† Effect on emerged Striga plant Effect on maize plants
Count (number)† Reduction
(%)
Striga damage
rating#
Plants attacked
by Striga (%)
Cobs weight
(kg/ha)
Grain yield
(kg/ha)
100-grain
weight (g)
Susceptible control 55 a 9 a 76 a 433 c 330 c 11.1 d
Untreated IR Maize control 10 b 3.7 b 17 b 3742 ab 2796 ab 15.0 bc
IR Maize + Arabic Gum (AG) 10 b 3.3 bc 14 bc 3027 b 2316 b 16.4 abc
IR Maize + Imazapyr + binder* 2 c 4.0 b 7 bc 3610 ab 2802 ab 17.1 a
IR Maize + Imazapyr+ AG 1 c 3.3 bc 3.0 bc 3290 ab 2511 ab 14.6 c
IR Maize + Biocontrol + AG 6 bc 3.0 c 10 bc 3913 a 3001 a 16.8 ab
IR Maize +Biocontrol+ Imazapyr + AG 0 c 100 3.0 c 0 c 3138 ab 2346 ab 15.8 abc
Mean 12 4.2 18 3022 2300 15.3
Treatment (Trt) *** *** *** *** *** ***
LSD (0.05) 6.5 0.7 15.2 843.1 670.3 2.1

• The biocontrol agents (BCAs) showed excellent - very good compatibility with:
– the herbicides Imazapyr, Metsulfuron Methyl (MSM) and Glyphosate.
– the seed treatment fungicides Apron plus, Dress force and Apron Star & Seedrex.
• Integration of the BC technology and imazapyr on a resistant IR maize for Striga
control, is possible as the two technologies showed compatibility after coating in a
single-dose application of combined seed treatments
• The results showed that the application of BC + imazapyr had additive effects in
– in suppressingStriga emergence in on station field trials
– showing significantly less Striga damage symptoms on maize plants compared to controls
• More on-farm field testing under high level ofStriga infestation and pressure is
required for monitoring the real impact of the combined efficacy of the two
technologies in grain yield improvement.
Summary - Compatibility with pesticides

Summary - Compatibility with pesticides
• In general, the biocontrol agents demonstrated excellent compatibility with the different
commonly used pesticides that containing a wide-range of active ingredients,
• key here is that seed of IR maize varieties can be dual coated with the herbicide and the
BCA and then fungicide - A triple-action seed coating package - and delivered to farmers
using the same input pathway
IR Maize seed Biocontrol Herbicide Fungicide
A triple-action seed coating package

Increasing awareness of benefit and safety
of BC technology
• Field days: A number of field days (>15) and farm days (3) were organized in collaboration with our
strategic partners KNARDA, BS-ADP & IAR-ABU in many trials sites in Bauchi & Kano.
• Targeted group: regulators, researchers, presidents of Farmers Association and Farmers
Community Representatives, farmers, dignitaries and village heads, women community
representatives, extension agencies and seed companies and input suppliers & policy makers
• Media interviews: a number of media interviews with BC team in and ISMA PM about striga BC
technology and ISMA project have been broadcasted by states radio & press media
• Meetings: a series of meeting were held with regulatory authorities e.g, agr. Commisioners, NAFDAC,
NAQS
• Many publicity documents produced, press and radio broadcasts have been released to increase
the awareness of benefit of biocontrol technology with broad relevant public audiences
• Radios: 15 broadcasts
– Kano: Freedom Radio in Kano (English & Hausa version)
– Bauchi: Community Radio in Bauchi in Hausa language; Bauchi Radio Cooperation (BRC); Globe FM Bauchi; Community
Radio in Ganjuwa; FM Community Radio Toro; Federal Radio Cooperation (FRCN)
• TVs: National Television Authority (NTA) ; Bauchi Television (BATV)
• Press media: Daily Trust Newspaper
Objective: To increase awareness of the saftey and potential benefit of BC technology with
regulators, researchers, extension agencies, farmers and other stakeholders

Increasing awareness – Field days
Demonstration of the tested biocontrol products to
the hon. Commissioner for Agriculture 2nd right) at
the demonstration trials in Ganjuwa, Bauchi
Field day at biocontrol trial in Gar, Alkaleri LGA, Bauchi
Field day at biocontrol trial in in Rurum, Rano, Kano
Field day at the demonstration trials in Tudun Wada, Kano
Women participants - strong presence in
the field day at demonstration trials in
Ganjuwa, Bauchi

Demonstration of the potential of BC technology with IITA DDGs (Research &
Partnership Directorates), Directors and principal scientists, in Kano
monitoring visits of IITA R4D activities in northern Nigeria in 2013, and 2014

Towards registration
• Strong contacts were established with NAFDAC led by Dr Mel aiming at promoting
potential benefit of BC technology with regulators towards registration in Nigeria
• A series of consultation visits and meetings between top officials of NAFDAC
(Registration & Regulatory Affairs Division) and IITA ISMA team (PM & BC), were made
and held in NAFDAC offices in Abuja, Lagos and Kano to facilitate the inspection and
registration process of BC technology
IITA ISMA team (PM & BC)
meeting NAFDAC DDG R&R in
Lagos

Towards registration
• Outcomes:
1. We had the opportunity to introduce in details our biocontrol technology and at the
same time receiving NAFDAC technical guidelines and requirements for field
efficacy inspection
2. NAFDAC assigned inspector for our biocontrol field efficacy trials led by Dr.
Ayahat Mudashir,
3. Efficacy and potential of biocontrol technology on farmer’s fields in season 2014
in Kano and Bauchi were inspected by NAFDAC inspection team,
4. Guidelines and requirements for full registration of BC product were collected
• IITA Communication Office developed Communication Advisory Brief, introducing
the new Striga biocontrol product, to name trademark, as a pre-requisite for full
registration.
• The next step
– to prepare and submit registration dossiers with complete toxicology data and
all required documents to NAFDAC, to facilitate the registration process of BC
in Nigeria

Biocontrol field inspection by NAFDAC team – Season 2014

Development of Molecular detection tools
• Molecular detection and monitoring tools specific to BC agent Foxy2 were
developed and validated by our project partner, UH in Germany,
• The detection tools were used to monitor the survival and persistence of BC
Foxy2 in rhizosphere soil of treated maize of Northern Nigeria.
• The results showed that the West African indigenous BC agent Foxy2 is
ecologically adapted to different AEZs of northern Nigeria.
• BC Foxy2 was able to survive following seed treatment application, planting and
harvesting, and proliferate in soil, and was detected and quantified with high
abundance (the abundance of Foxy2, gene copy numbers g-1 of dry soil, is high
and ranging from 1x105 – 8x106 copies g-1 soil) in rhizosphere soil after
harvesting of maize crop.
• The survival and high abundance of the BC Foxy2 in soil after 5 months of
planting may enable the BC Foxy2 to play role in declining Striga seedbank in
the future.

• The objective: is to screen for highly pathogenic and virulent Fos indigenous strains for
their future promotion as BC agents for Striga control.
• 25 new strains of Fos were isolated from diseased Striga plants in Nigeria, and
identified and their genetic diversity and mycotoxin production studied by Prof. Altus
from Stellenbosch University in South Africa.
• The screening results showed that some of these new indigenous Fos strains are
highly pathogenic and virulent against Striga
• The strains CVA-6143, CVA-6144, CVA-6142, CVA-6162, CVA-6166, showed good
potential in pot trials and on-station preliminary field trials in
– suppressing Striga emergence as compared to the untreated controls,
– they showed significantly less Striga damage symptoms on maize plants,
– and they improved host plants (maize & sorghum) growth and performance to the same level
of our reference isolate Foxy2 and PSM197.
• More field testing (on station & on farm) under high level of Striga infestation and
pressure is required to evaluate the efficacy and potential of the new indigenous
promising Fos strains in grain yield improvement.
Pathogenicity of the new indigenous Fos strains -
Summary

Pathogenicity of new Fos isolates – pot trial
Foxy2
Foxy2 PSM197
PSM197Control
Control
N-6126
N-6126
N-6144
N-6144

Collaboration with other scientists to
strengthen Striga research in IITA
• I am sharing my experience in Striga biology and seed treatment technology with
maize breeder, molecular geneticist and my colleagues from ISMA project (Dr.
Menkir, Dr. Gedil, Dr. Oluoch, Dr. Kamara, Dr. Beed) to strengthen Striga research in
IITA
Understanding the genetic diversity in S. hermonthica in Nigeria and Kenya,
characterization and identification of the mechanisms of resistance in maize:
• This is expected to help in developing maize cultivars with durable resistance to emerging new
ecotypes of S. hermonthica, adapted to different AEZs in Nigeria & Kenya.
• This is PhD research: being carried out by Mr. Nnanna Unachukwu, University of Ibadan,
Nigeria. Supervisors Dr. M. Gedil, Dr. A. Menkir & Dr. A. Elzein. Work is progressing.
Evaluating the influence of coating material and herbicide dose on the efficacy
of MSM and imazapyr herbicides – treated seeds of the IR-Maize Hybrids in
controlling Striga:
• This is MSc thesis: being carried out by Mrs. Moriam Azeez, University of Ibadan, Nigeria.
Supervisors Dr. A. Menkir & Dr. A. Elzein (IITA). Work is progressing.
• Identification of the most compatible coating material and optimum dose of the herbicides will
enhance the commercial production and marketing of treated seeds of herbicide-resistant
maize hybrids by private sectors to farmers to control Striga in Nigeria

Future plan
Registration of biocontrol product (bioherbicide) in Nigeria:
– To prepare and submit the registration dossiers and required documents to NAFDAC,
– To work with NAFDAC to complete the registration process of the BC product in Nigeria,
Establishment of a wide-scale field demonstration:
– to show-case of the potential of biocontrol technology
– to promote, increase awareness and enhance dissemination and use of BC technology
Integration with other Striga management technologies:
– Field integration with legume rotation and IR varieties combined with imazapyr,
– Evaluate the benebif and additive effects on maize yield and Striga control
Establishment of BC inoculum mass production and development of strategy for
scaling-up and link with IITA’s Business Incubation Platform (BIP):
– To facilitate scaling-up and commercialization
– Implementation pathway to follow Aflasafe model
Monitoring the persistence of BC agents in the soil and rhizosphere interactions:
– Long-term persistence of BC agents will be useful for determining the declining in the Striga seed
bank, and the amount of inoculum needed for successive seasonal applications
– To understand the rhizosphere interactions (synergistic or antagonistic effects) with other soil
inhabitants

Acknowledgements
 BMG Foundation - Funding
 Dr. Fen Beed, World Vegetable Center, (former IITA pathologist, and leader of Striga BC)
 Dr. Ranajit BANDYOPADHYAY, Dr. Joseph Atehnkeng, Mr. Lawrence Kaptoge and Pathology unit
staff – for hosting this BC lab activities
 Dr Ylva Hilbur (DDG R4D),
 Dr Chikoye ISMA project Director (Director, Southern Africa Hub)
 Dr Robert Asiedu, Director of West Africa Hub,
 Dr. Menkir, Dr. Meseka, Maize Unit staff at Ibadan and Mokwa station, Poal & Azeez
 Dr. Mel ISMA PM
 Dr. F. Rasche & Miss J. Zimmermann (University of Hohenheim, Germany)
 Prof. A. Vilioen & Miss M. Du Plessis (University of Stellenbosch, South Africa)
 Mr. Lawal Bala
 Prof. Zarafi, Mr. Ahmed Tijani, IAR-ABU
 Dr. Kamara, and his technical staff, Reuben & Kadafur
 KNARDA (Kano State) staff
 BS-ADP (Bauchi State) staff
 Many others

“If you want to go fast, go alone. If
you want to go far, go together.” –
an African proverb

Cost of BC technlogy
• The actual cost of coating maize seeds with the
biocontrol Fos for cultivation of one ha using
professional seed coating technology to be
performed at IITA HQ in Ibadan is $ 16.8 (2,738.4
NGN).
• This includes
– the cost of coating material (Arabic gum),
– production cost (personal and electric power
consumption),
– logistics (packaging, transportation, loading, unloading) ,
– and marginal profit of the agro-dealers
• The reference (standard) cost of the same
biocontrol product for the same target for seed
coating by a professional biocontrol private
company based in Kenya (The Real IPM). The
end-user cost per ha =$ 23.14, that includes
production cost and profit of the company.
Material and production Cost per kg of seed ($)
a. Cost of Arabic gum as coating material
The calculation is done based on the optimized seed coating protocol that SUET
used to perform professional seed coating for the validation phase during
the last 3 yeas
 The concentration of Arabic gum used was a 20% solution in water
with an application rate of 70g solution/kg seed i.e. 14 g of Arabic
gum per /kg seed.
 The price of 1 kg of Arabic gum we purchased from Kano in Nigeria is
120.00 Naira (equivalent to 0.74 $).
 The price of 14 g of Arabic gum for coating 1 kg of seeds = 0.21 $
0.21
a. Fungal inoculums
 Since we use agricultural by-products (maize and sorghum stover)
that are available in the regions where Striga is a major problem with
no or negligible price, the cost of inoculum production was negligible.
The estimated cost is only for the electric power consumption of the
shaker and personal
0.05
a. Production cost (processing): Personal cost (technical staff) for
coating 1 kg seeds.
 This is calculated based on the upper limit rate that IITA PG6
technical regular staff is earning per hour; the amount of seeds in kgs
that the coating machine we have in Ibadan, able to treat per hour;
and then the cost is adjusted per kg of seed
0.10
a. Production cost (processing): Electric power consumption cost that
the coating machine consume for coating 1 kg seed
 This is calculated based on the accurate values of the power
consumption of the machine per hour (kwh) and the unit price of the
one kw at IITA HQ, that provided by FMS unit.
0.009
a. IITA Royalty for quality control and maintenance 0.10
a. Transportation to Northern Nigeria
 This is calculated based on the accurate prices of maize grain
transportation from Ibadan to Kano including packaging, loading and
unloading costs per kg that provided by FMS transportation office
and Aflasafe plant.
0.07
a. Marginal profit of the agro-dealers (distributors or seed companies)
 50 Naira per coated kg
0.30
Total cost of coating and delivering 1 kg of seed to end-user farmer 0.84
Total cost of the amount of coated seeds for 1 ha (20kg seed/ha) 16.8

Healthy emergedStriga
0
30
60
90
120
150
180
210
240
270
300
330
LSD (0.05) = 71 (***) LSD (0.05) = 88 (***)
80%
72%

(3 locations in SS)
0
500
1000
1500
2000
2500
3000
3500
4000
b
b
a
a
LSD (0.05) = 542 (***)
b
c

(3 locations in SS)
Diseased emerged Striga plants (%)
0
10
20
30
40
50
60
70
80
90
100
b
b
LSD (0.05) = 17.8 (***) LSD (0.05) = 15.8 (***)
a
b
a
b
LSD (0.05) = 17.9 (***)

(3 locations in SS)
0
500
1000
1500
2000
2500
3000
3500
4000
bc c
a
b
LSD (0.05) = 270 (***)
d
e
85%
42%
BlockA BlockB BlockC
T3 T5 T6
2m 2m
1m
1m
T1 T3 T4
T5 T6 T2
T2 T1 T3
T4 T2 T5
1m
1m
T6 T4 T1
2m 2m
Trial lay-out

(3 locations in SS)
Diseased emerged Striga plants (%)
0
10
20
30
40
50
60
70
80
90
100
b
b
LSD (0.05) = 13.8 (***)
a
b
a
b

Biocontrol efficacy on farm research trials
(3 locations in SS)
Healthy emergedStriga
0
5
10
15
20
25
30
35
b
b
LSD (0.05) = 4.9 (***) LSD (0.05) = 21 (*)
a
66%
a
b
b
96%

Biocontrol efficacy on station
(under artificial Striga infestation)
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Susceptible Resistant
b
LSD (0.05) = 622 (***)
ab
a
d
cd
c

BC + Resistant, deep
Green, and no visible Striga
damage symptoms
Susceptible control yellowish,
extensive streaking/scorching &
drying, as a result of Striga damage
BC + Resistant (few Striga) Susceptible control (many Striga)
On station trial at Mokwa

• In season 2014, the application of BC Fos in combination with both Striga susceptible and
resistant varieties significantly
• reduced Striga incidences, and damage symptoms on maize plants
• caused high disease incidence on the emerged Striga plants,
• and increased the grain yield on average by 104% (1849 kg/ha), compared to farmer’s choice
(local maize variety) on farm.
• BC showed also compatibility and additive effect (added value ) with the resistant variety on
farm and on station.
• BC contributed to the grain yield increase of the resistant variety by 57% (1114 kg/ha) on farm,
compared to farmer’s choice.
• In conclusion, the results of field validation trials of two successive seasons (2013 & 2014)
showed that the application of biocontrol in combination with both Striga resistant and
susceptible varieties significantly reduced Striga incidences and damage symptoms and improved
grain yield in range of 82% (1600 kg/ha) in a consistent manner, regardless of the AEZ or maize
variety used.
• Hence, the advantage of combing BC with the resistant maize and deliver it in a package to
farmers using the same input pathway will reduce transaction and application costs, increase the
grain yield and thus will enhance further the cost-benefit of the two technologies
Summary – Biocontrol efficacy validation

Grain yield results of the on-farm trials across Bauchi and
Kano for Biocontrol Technology - 2014

Net benefit of Biocontrol & Resistant for Bauchi and Kano (NGN ha-1)
0
20000
40000
60000
80000
100000
120000
Biocontrol
28,540
67,718
113,763
29,930
64,351
105,817
Bauchi Kano
Netbenefit(NGN/ha)
NGN
255%
300%
BC technology is cost effective when combined with the resistant varieties in Bauchi & Kano

Net benefit of Biocontrol & Susceptible for Bauchi & Kano (NGN ha-1)
0
20000
40000
60000
80000
100000
120000
Farmer's variety Susceptible Susceptiblet +
Biocontrol
24,455
64,865
103,123
1,541
35,453
81,470
Bauchi Kano
Netbenefit(NGN/ha)
NGN
512%
322%
BC technology is cost effective when combined with the susceptible varieties in Bauchi & Kano

Average rate of return of Biocontrol & Resistant for Bauchi and Kano
Average rate of return
(%) =
Net benefit / Total
variable costs (N/ha)
38.5
79.5
110
38.5
74.2
105.5
0
20
40
60
80
100
120
Biocontrol
Bauchi Kano
Averagerateofreturn(%)
The rate of return on an
investment

Average rate of return of Biocontrol & Susceptible for Bauchi and Kano
Average rate of return
(%) =
Net benefit / Total
variable costs (N/ha)
33.5
78.5
112.5
2
40.7
85
0
20
40
60
80
100
120
Biocontrol
Bauchi Kano
Averagerateofreturn(%)
The rate of return on an
investment

• The results of cost benefit analysis of two successive seasons (2013 & 2014) showed
that BC technology is cost effective with similar trend in Bauchi and Kano states
irrespective of the maize variety used
• With a average net benefit of 112,849 NGN/ha and 99,376 NGN/ha when combined
with the resistant and susceptible varieties, respectively, is 4 times and 3 times more
compared to 40,903 NGN/ha and 23592 NGN/ha (32248 NGN/ha ) for their farmer
choice (local varieties) in 2014.
• This cost benefit result strongly supports the positive obtained efficacy and yield
improvement results and strengthens the future of the BC technology.
• Hence, the potential advantage of combing BC with the resistant maize and deliver it
in a package to farmers using the same input pathway:
– reduced transaction and application costs,
– increased the grain yield
– and enhanced the cost-benefit of the two technologies.
Summary – cost benefit

Establishment of biocontrol inoculum production and seed coating
technology unit at IITA HQ in Ibadan
Seed coating machine used (back view) Seed coating machine used (front view)
Maize seeds in the of the coating machine before coating Maize seeds in the of the coating machine during coating
Small seed coating machine purchased with support from our DG Dr.
Sanginga, and in partnership with Dr Menkir,
Dried Chlamydospores
Fungal inoculum
Benefits
1. BC inoculum mass production and seed coating
technology established at IITA,
2. logistic and technical costs of performing seed
coating outside Nigeria will be saved,
3. other relevant research at IITA will be facilitated
and strengthened using this unit (e.g IR maize
coating with imazapyr & MSM),
4. capacity in this innovative technology will be built.

• The objective: is to screen for more promising, highly virulent Fos indigenous strains for their
future promotion as BC agents for Striga control.
• 25 new strains of Fos were isolated from diseased Striga plants collected in 2012 from different host
crops and AEZ in Nigeria, and identified and their genetic diversity and mycotoxin production studied
by Prof. Altus from Stellenbosch University in South Africa.
• Inoculums of the 27 Fos isolates including Foxy2 & PSM197 were prepared using wheat grains, and
their pathogenicity against Striga was evaluated using maize and sorghum in pot trials in screen house
in Kano station.
• Results: some of these new indigenous Fos strains showed to be highly pathogenic and virulent
against Striga - The strains CVA-6143, CVA-6144, CVA-6142, CVA-6162, CVA-6166, showed
potential in
– suppressing Striga emergence and significantly reducing Striga damage symptoms on maize plants,
– Also they improved host plants maize growth and performance (plant height, stalk and root biomass) to
the same level of our reference isolate Foxy2 and PSM197.
Pathogenicity of the new Fos isolates
Inoculated-Fosnon-inoculated
Inoculums of Fos strains on wheat grains

Pathogenicity of new Fos isolates – pot trial
Foxy2
Foxy2 PSM197
PSM197Control
Control
N-6126
N-6126
N-6144
N-6144

• Furthermore, the efficacy and potential of these virulent 5 Fos strains in suppressing Striga and
improving grain yield, in comparison with the reference isolates (Foxy2 & PSM197) were
evaluated in combination with susceptible maize variety.
• The Fos isolates were evaluated using Pesta formulation technology [Pesta Granules:
inoculums of the strains were encapsulated in a matrix of durum wheat-flour, kaolin, and
sucrose], prepared at IITA HQ in Ibadan.
• Evaluated under artificial Striga infestation in small preliminary trial.
• Dose: 2 g of Pesta granules per planting hole at a concentration of 1x105 cfu g-1.
Pathogenicity of the new Fos isolates – on station
non-inoculated
Pesta with Foxy2
Pesta without BCA, control
Planting hole inoculation with Pesta
granules at Mokwa

Biocontrol efficacy of the new Fos isolates
(under artificial Striga infestation with susceptible)
Striga emergence
0
2
4
6
8
10
12
14
16
18
Foxy2
PSM197
N-6144
N-6143
N-6142
N-6162
N-6166
Control
EmergedStrigaplants(No./3m2)
LSD (0.05) = 6.8 (*)
ab
a
b
bb
b
b
b

Striga damage symptoms on maize plants
# Striga damage rating on a scale of 1-9, where 1 = no damage symptoms and 9 = severe damage symptoms due
to Striga (Berner et al., 1997)
1
2
3
4
5
6
7
8
9
Foxy2
PSM197
N-6144
N-6143
N-6142
N-6162
N-6166
Control
Strigadamagerating(1-9)
LSD (0.05) = 1.7 (*)
b
a
b b
b
bb
b

Compatibility of BC with herbicides - MSM (DuPont)
Effect of Metsulfuron Methyl (MSM) on mycelial growth and sporulation of biocontrol agents
MSM concentration
Foxy2 PSM197
Mycelial growth (Ø cm) Conidia ml-1 (x106) Mycelial growth (Ø cm) Conidia ml-1 (x106)
0.0 g/L 3.9 a 0.7 d 3.9 a 1.4 a
0.5 g/L 3.8 a 1.3 c 3.6 b 1.1 ab
1 g/L 3.6 a 2.4 b 3.2 c 1.0 b
2 g/L 3.1 b 4.1 a 2.3 d 0.7 c
LSD (0.05) 0.3 0.44 0.13 0.3
Application rate of MSM for Striga control = (0.000025 g/sorghum seed, 0.00036 g/maize seed)
• Both BCAs (Foxy2 & PSM197 ) showed excellent compatibility with Metsulfuron Methyl (MSM)
even at the highest tested concentration i.e the mycelial radial growth and sporulation of the two
isolates were not negatively affected
• Excellent compatibility with Glyphosate was also achieved
• A good compatibility with Apron Plus & Pron Star at the lowest concentration( 0.023, 0.008 g/L),
which is 10 times more than the recommended dose
• Excellent compatibility with Dress force at (0.024 g/L) and 50% compatibility with Seedrex at (0.024
g/L) which is 10 times more than the recommended dose .

Compatibility with imazapyr herbicide
• IR maize seeds were successfully coated with a single-dose seed treatment of BCA inoculums and
imazapyr by partner in Germany using professional seed coating and Arabic Gum as adhesive
• The IR maize seeds were uniformly coated and dust-free and with a concentration of 1.2x104 CFU of
fungal inoculums and 0.00084 g of imazapyr per coated maize seed
Coated with BCCoated with BC + Imaza.Untreated control
Effect of imazapyr on mycelial growth of Foxy2, film-
coated on IR maize, PDA media
Excellent compatibility with imazapyr after coating i.e no negative
affect on Foxy2 mycelial radial growth was recorded.
Imazapyr concentration)
Foxy 2
Mycelial growth (Ø cm)
Coated Foxy2 on 0.0 g/L 3.72
Coated Foxy2 on 0.5 g/L 3.73
Coated Foxy2 on 1 g/L 3.72
Coated Foxy2 on 2 g/L 3.70
Co-coated Foxy2 + imazaypr on 0.0 g/L 3.70
LSD (0.05) 0.08

Objective: to evaluate the combined control efficacy of biocontrol Fos and imazapyr
herbicide on Striga control and crop yield improvement, that delivered in a single-
dose application of seed treatment.
Compatibility of biocontrol with imazapyr – lab results
– BC agents showed excellent compatibility with the herbicides imazapyr
– Imazapyr did not interfere with the BC during seed coating process,
– did not show inhibitory effect on BC viability, mycelia growth & sporulation after coating
• Based on these compatibility results, doses and complementary seed coating
protocols have been developed and optimized at IITA HQ in Ibadan
• IR maize seeds were coated with a single-dose application of combined seed
treatments of BC inoculums and imazapyr using professional seed coating
technology and Arabic Gum performed at IITA HQ in Ibadan
• The combined control efficacy of BC and imazapyr on Striga control and
improvement of IR maize performance was evaluated artificial Striga infestation in
on station field trials.

• Biocontrol + imazapyr = inhibited Striga emergence, but not grain yield improvement was
recorded, but also ..
Combined efficacy of biocontrol and imazapyr, co-coated on IR maize seeds, on Striga control and
maize performance evaluated under artificial infestation in 2 locations in Nigeria in 2013
Treatment† Effect on emerged Striga plants Striga damage
rating#
Effect on maize plants
Number per plot‡ Diseased (%) Cobs weight
(g/plant)
Grain yield
(kg/ha)
100-grain weight
(g)
Grain yield
(kg/ha)
Untreated control 17 a 4 c 5 a 83. 7 3334 19 2659
IR Maize + Arabic Gum (AG) 15 a 26 b 4.7 ab 82.0 3528 19 3199
IR Maize + Imazapyr + binder* 10 a 7 c 4. 3 abc 72.0 3369 18.5 3268
IR Maize + Imazapyr+ AG 1 b 0 c 4 bc 71.5 3089 18.8 2904
IR Maize + Biocontrol + AG 17 a 11 c 3.6 c 80.4 3308 18.4 3015
IR Maize +Biocontrol +
Imazapyr + AG
0 b 100 a 3.6 c 77.3 3293 19.7 3073
Mean 10 25 4.2 77.8 3320 18.9 3019
Treatment (Trt) ** *** * ns ns ns ns
LSD (0.05) 10 14.9 0.9 21.3 846.3 1.7 909.4
† AG = Arabic Gum; ‡ number of Striga plants counted in 10.1 m2. * Significant at p<0.05; ** Significant at p<0.01; *** Significant at p<0.001;

• Summary – Increasing awareness
• Increased awareness of potential benefit of biocontrol technology by regulators,
researchers, extension agencies, farmer representatives, and other stakeholders, has
been successfully realised
Summary – Increasing awareness
• DDGs, directors photos
• Promotion of BC technology with IITA DDGs (Research and Partnership
Directorates), Directors of West and Southern Africa Hubs, and several principal
scientists, Tudun Wada, Oct. 2013
• Summary registration
• Well-established contacts and consultation with NAFDAC initiated and created,
• efficacy and potential of biocontrol technology on farmer’s fields, inspected by
NAFDAC inspection team,
• guidelines and requirements for full registration of biocontrol product collected,
• and Communication Advisory Brief, introducing our biocontrol product was developed,
for facilitation of the registration of the technology.

Maize performance (stalk dry biomass, g plant-1)
0
10
20
30
40
50
60
70
80
90
100
110
120
130
Foxy2
PSM19
7
N-6144
N-6143
N-6142
N-6162
N-6166
Control
Maizestalkdrybiomass(g/plant)
LSD (0.05) = 32 (*)
ab
a
b
ab
ab ab
ab
ab
They improved maize stalk biomass in a range of 17-46% to the same level of our reference isolate Foxy2
& PSM197. However, the strain CVA-6144 showed the highest significant increase.

Collaboration with other scientists in different
aspects of Striga research in IITA
• I am sharing my experience in Striga biology and seed treatment technology with
maize breeder, molecular geneticist and my colleagues from ISMA project (Dr.
Menkir, Dr. Gedil, Dr. Oluoch, Dr. Kamara, Dr. Beed) to enhance and strengthening
Striga research in IITA
Understanding the genetic diversity in S. hermonthica in Nigeria and Kenya,
characterization and identification of the mechanisms of resistance in maize:
• This will enhance pyramiding of multiple resistances and facilitate development of maize
cultivars with durable resistance to emerging new ecotypes of S. hermonthica, adapted to
AEZs where Striga is a major problem in Nigeria & Kenya.
• This is PhD research: being carried out by Mr. Nnanna Unachukwu, University of Ibadan,
Nigeria. Supervisors Dr. M. Gedil, Dr. A. Menkir & Dr. A. Elzein.
Evaluating the influence of coating material and herbicide dose on the efficacy
of MSM and imazapyr herbicides – treated seeds of the IR-Maize Hybrids in
controlling Striga:
• This is MSc thesis: beig carried out by Mrs. Moriam Azeez, University of Ibadan, Nigeria.
Supervisors Dr. A. Menkir & Dr. A. Elzein (IITA).
• Identification of the most compatible coating material and optimum dose of the herbicides will
provide an optimized seed coating protocols that will enhance the commercial production and
marketing of treated seeds of herbicide-resistant maize hybrids by private sectors to farmers
to control Striga in Nigeria

Table 1: Economic impact analysis of ongoing biological control
projects in Africa: the estimated savings were achieved for costs far
below 1%.

Worldwide distribution of Striga species
S. asiatica
S. gesnerioides
S. hermonthica

Options of Control Methods
• Preventive methods
• Cultural methods
– Crop rotation with trap and catch crops
– Use of organic material
– Transplanting
• Host plant resistance
• Chemical methods
– Soil disinfection
– Herbicides
– Mineral fertilizer
• Physical methods
– Hand weeding
– Soil solarisation
• Biological methods
• Single control methods
are not sufficient to
control Striga effectively
and economically.
• Therefore, an integrated
approach in which the
biological control
represent an important
component appears to
be the ideal strategy for
reducing Striga
Introduction:

Season 2011
• Nigeria experienced heavy rains and flooding in 2012
• The heavy rains has caused water-logging in some of our biocontrol trials.
• This has severely affected the germination and emergence of Striga and caused
stunting of maize plants.
Problems encountered during field validation
Regardless of the problem encountered, the results obtained from the field trials
established in 2013 and 2014 provided sufficent data and evidences that showed
significant effects of the bioherbicide onStriga control and maize yield
improvement .
• Due to late inception of the project, the field trials were sown late by 5-6 weeks
after the normal planting date,
• Striga did not emerge as would occur naturally if sowing had been achieved at
the onset of the rains.
Season 2012

The impact of IITA-led biological control of major pest in sub-Saharan ...
Impact through biological control?
Neuenschwander (2004). Harnessing nature in Africa. Nature, 432; 801
Alene, A. D. P. Neuenschwander, V.M. Manyong, O. Coulibaly & R. Hanna (2005). IITA IMPACT SERIES. 26 pp.
Pest Countries under economic
analysis
Estimated cost saving in
millions of US $
Cassava mealybug 27 African 20 000
Cassava green mite Benin, Ghana,
and Nigeria 2 000
Mango mealybug Benin 531
Water hyacinth Benin 260
Aflatoxins Nigeria, Kenya, Senegal,
Burkina Faso, Tanzania,
Zambia, Mozambique, Ghana,
Mali & others
Dr. Ranajit and Aflasafe team
Why biological control ?
• it is environmentally friendly and ecologically sound,
• can be specific to the target host, and effective
• and has the potential to be economically viable.

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