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

http://www3.telus.net/conrad/images/scp_c04.jpg

http://www3.telus.net/conrad/images/b_striga_photo_04_maize_striga_on_roots_close.jpg

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, SudanGeographical 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


Protocol1. 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 weed9. Field efficacy and performance (field testing);10. Registration11. 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 materialChlamydospor

es

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 validation3. Socio-economic analysis and cost-benefit 4. Compatibility with pesticides and other technologies5. Increase awareness6. Towards registration7. Molecular detection tools

8. Future plan

Diseased Striga plants


Partnerships

http://www.gatesfoundation.org/Pages/home.aspx


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 PSM197 Foxy2 Pesta C Contro

l

PSM197 Foxy2 Pesta C Control

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

Control

PSM197 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

Benefits1. 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)

Resistant Susceptible0

500

1000

1500

2000

2500

3000

3500

4000

4500Farmer's choice Untreated control Biocontrol

Mai

ze g

raim

yie

ld (k

gha-

1)

c

LSD (0.05) = 165 (***)

b

a

a

LSD (0.05) = 229 (***)

b

c

108%

101%

45%


Biocontrol efficacy in on-farm trials (47 locations, 27 with resistant, 20 with susceptible, 2014)

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


Stri

ga d

amag

e ra

ting#

b

a

c

a

bc

LSD (0.05) = 0.3 (***) LSD (0.05) = 0.36 (***)



Striga emergence


30

60

90

120

150

180

210

240

270

300

330

Farmer's choice Untreated control BiocontrolEm

erge

d St

riga

plan

ts (N

o.10

m-2

)

b

b

b

LSD (0.05) = 68 (***) LSD (0.05) = 84 (***)

a

b

a



Diseased (%) emerged Striga plants


10

20

30

40

50

60

70

80

90


Dise

ased

Stri

ga p

lant

s (%

)

b

c

LSD (0.05) = 5.4 (***) LSD (0.05) = 8.1 (***)

a

b

a

cDiseased Striga plants



Reduction (%) in emerged healthyStriga compared to BC application


10

20

30

40

50

60

70

80

90

100 9693

80

72

Farmer's choice Untreated controlD

isea

sed

Strig

a pl

ants

(%)


BC efficacy under SS AEZ on-farm(26 locations, 15 with resistant, 11 with susceptible, 2014)


95TZE COMP4 C3 F2TZE Comp.5-W C7

Resistant Susceptible 0

500

1000

1500

2000

2500

3000

3500

4000

4500Farmer's choice Untreated Control Biocontrol

Mai

ze g

raim

yie

ld (k

gha-

1)

c

LSD (0.05) = 245 (***) a

b

a

LSD (0.05) = 282 (***)

c

b

113%

113%

51%


BC efficacy under NGS AEZ on farm(21 locations, 12 with resistant, 9 with susceptible, 2014)


TZL COMP1SYNY-1F2


500

1000

1500

2000

2500

3000

3500

4000

4500Farmer's choice Untreated Control Biocontrol

Mai

ze g

raim

yie

ld (k

gha-

1)

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 controlsThis indicates that the BC efficacy is very consistent regardless of the maize variety

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 28-500

0

500

1000

1500

2000

2500

3000

3500

4000

Farmer choice Untreated Control Biocontrol

Incr

ease

in m

aize

gra

in y

ield

(kgh

a-

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 controlsThis indicates that the BC efficacy is very consistent regardless of the maize variety

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23-500

0

500

1000

1500

2000

2500

3000Farmer choice Untreated Control Biocontrol

Incr

ease

in m

aize

gra

in y

ield

(kgh

a-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)



500

1000

1500

2000

2500

3000

3500

4000Untreated control Control + AG Biocontrol

Mai

ze g

raim

yie

ld (k

gha-

1)

bc c

a

b

LSD (0.05) = 270 (***)

d

e

85%

42%

Biocontrol on-farm research field trial at Gar, Alkaleri, Bauchi

BC+ResistantControl 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. RESISTANTResistant + 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 4,507.149 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 Benefit17 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 = Gross farm gate benefits / Total

variable input costs (N/ha)

Farmer's variety Resistant Resistant + Biocontrol0

0.5

1

1.5

2

2.5

1.39

1.8

2.1

1.38

1.74

2.1

Bauchi Kano

Benefit cost ratio



Benefit cost ratio of Biocontrol & Susceptible for Bauchi and Kano, 2014

BC technology is cost effective;

Benefit cost ratio = Gross farm gate benefits / Total

variable input costs (N/ha)

Farmer's variety Susceptible Susceptible + Biocontrol

0

0.5

1

1.5

2

2.5

1.33

1.78

2.12

1.02

1.41

1.85

Bauchi Kano

Benefit cost ratio


Cost benefit of BC technology and resistant

Net benefit (average Bauchi & Kano) for seasons 2013 & 2014 (NGN ha-1)

BC technology is cost effective

when combined with the resistant in

season 2013 and 2014


20000

40000

60000

80000

100000

120000

52570

92893

115907

29235

66034.5

109790

Season 2013 Season 2014

Net benefit (NG

N/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

34,186

77,628

106,455

12,998

50,159

92,296.5

Season 2013 Season 2014

Net benefit (NG

N/ha)

NGN

610%

213%

BC technology is cost 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 herbicidesEffect 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 BC

Coated 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 abcMean 12 4.2 18 3022 2300 15.3Treatment (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

http://www.google.co.uk/url?url=http://www.dreamstime.com/stock-image-yellow-corn-seed-realistic-photo-image-macro-close-up-grain-isolated-white-background-image34700591&rct=j&frm=1&q=&esrc=s&sa=U&ved=0CDIQ9QEwDmoVChMIma2lr6qIxgIVp6HbCh2nPADv&usg=AFQjCNE_58VGeBPV96kBSjZVd83G0QPdyg

http://www.google.co.uk/url?url=http://www.dreamstime.com/stock-image-yellow-corn-seed-realistic-photo-image-macro-close-up-grain-isolated-white-background-image34700591&rct=j&frm=1&q=&esrc=s&sa=U&ved=0CDIQ9QEwDmoVChMIma2lr6qIxgIVp6HbCh2nPADv&usg=AFQjCNE_58VGeBPV96kBSjZVd83G0QPdyg


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 planRegistration 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 0.10a. 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


30

60

90

120

150

180

210

240

270

300


Emer

ged

Strig

a pl

ants

(No.

10m

-2)

LSD (0.05) = 71 (***) LSD (0.05) = 88 (***)

80%72%





500

1000

1500

2000

2500

3000

3500


Mai

ze g

raim

yie

ld (k

gha-

1)

bb

aa

LSD (0.05) = 542 (***)

b

c



Diseased emerged Striga plants (%)

Diseased Striga plantsResistant Susceptible

0

10

20

30

40

50

60

70

80

90


Dis

ease

d St

riga

plan

ts (%

)

bb

LSD (0.05) = 17.8 (***) LSD (0.05) = 15.8 (***)

a

b

a

b

LSD (0.05) = 17.9 (***)





500

1000

1500

2000

2500

3000

3500


Mai

ze g

raim

yie

ld (k

gha-

1)bc c

a

b

LSD (0.05) = 270 (***)

d

e

85%

42%

Block A Block B Block CT3 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



Diseased emerged Striga plants (%)

Diseased Striga plants


10

20

30

40

50

60

70

80

90


Dis

ease

d St

riga

plan

ts (%

)

bb

LSD (0.05) = 13.8 (***)

a

b

a

b


Biocontrol efficacy on farm research trials (3 locations in SS)

Healthy emergedStriga


5

10

15

20

25

30


Emer

ged

Strig

a pl

ants

(No.

10m

-2)

b

b

LSD (0.05) = 4.9 (***) LSD (0.05) = 21 (*)

a

66%

a

b

b96%



Biocontrol efficacy on station (under artificial Striga infestation)

Susceptible Resistant0

500

1000

1500

2000

2500

3000

3500

4000


Mai

ze g

raim

yie

ld (k

gha-

1)

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)


20000

40000

60000

80000

100000

120000

28,540

67,718

113,763

29,930

64,351

105,817

Bauchi Kano

Net benefit (NGN/ha)

NGN

255%

300%

BC technology is cost effective when combined with the resistant varieties in Bauchi & Kano


Cost benefit of BC technologyNet benefit of Biocontrol & Susceptible for Bauchi & Kano (NGN ha-1)

Farmer's variety Susceptible Susceptiblet + Biocontrol

0

20000

40000

60000

80000

100000

120000

24,455

64,865

103,123

1,541

35,453

81,470

Bauchi Kano

Net benefit (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)


20

40

60

80

100

120

38.5

79.5

110

38.5

74.2

105.5

Bauchi Kano

Average rate of return (%)

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)


0

20

40

60

80

100

120

33.5

78.5

112.5

2

40.7

85

Bauchi Kano

Average rate of return (%)

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

Benefits1. 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-Fos

non-inoculatedInoculums 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

Foxy

2

PSM

197

N-61

44

N-61

43

N-61

42

N-61

62

N-61

66

Cont

rol0

2

4

6

8

10

12

14

16

18 E

mer

ged

Strig

a pl

ants

(No.

/3m

2)

LSD (0.05) = 6.8 (*)

ab

a

bbb

b

bb



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)

Foxy

2

PSM

197

N-61

44

N-61

43

N-61

42

N-61

62

N-61

66

Cont

rol1

2

3

4

5

6

7

8

9St

riga

dam

age

ratin

g (1

-9)

LSD (0.05) = 1.7 (*)

b

a

b bb

bbb


Compatibility of BC with herbicides - MSM (DuPont) Effect of Metsulfuron Methyl (MSM) on mycelial growth and sporulation of biocontrol

agentsMSM 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 BC Coated 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 3019Treatment (Trt) ** *** * ns ns ns nsLSD (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)

Foxy

2

PSM

197

N-61

44

N-61

43

N-61

42

N-61

62

N-61

66

Cont

rol0102030405060708090

100110120130

Mai

ze s

talk

dry

bio

mas

s (g

/pla

nt)

LSD (0.05) = 32 (*)

ab

a

b

abab ab

abab

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%.

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 infestation in the future.

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 260Aflatoxins 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.

testing of a bioherbiode technology for striga control

Government & Nonprofit