Science Innovation for Better Livelihoods

Case Study:

PUSH-PULL TECHNOLOGY

FOR SUSTAINABLE INTENSIFICATION OF

AGRICULTURE IN AFRICA www.icipe.org

www.push-pull.net

Jimmy Pittchar

FARA General Assembly and 6th Science Week 15-20 July 2013

Accra International Conference Centre, Accra, Ghana

Maize worth US$ 1.5b is lost annually due to stemborers in

SSA

Chilo partellus

Busseola fusca

The parasitic witchweeds, Striga spp, threaten the lives of over

100 million people in Africa and infest 60% of arable land in the savannah

region causing an annual loss of billions of dollars to African agricultural

economy.

Khan et al. 2007. Crop Science 47:730-734

About 2/3 of 73 million ha of land devoted to cereal

production in Africa is infested with striga.

S. hermonthica S. asiatica

Distribution of Striga Weed in Africa

I. DEVELOPMENT PROCESS:

Formulating

a push-pull strategy for Africa

Africa needs simple, inexpensive, multi-faceted technologies which are

developed with farmers’ participation and are tailored to the diversity of their

farming systems

(Prof. Thomas R. Odhiambo, 1983)

The ‘Push-Pull’ scientific innovation

The ‘Push-Pull’ strategy is a novel approach in pest management which uses a repellent intercrop and an attractive trap plant. Insect pests are repelled

from the food crop and are simultaneously attracted to a trap crop.

Attract naturalenemies

Moths are pushed away

Attract moths

Trap Crop

Main Crop

Cook, Khan and Pickett (2007) Annu. Rev. Entomol. 52 : 375-400

“Push – Pull” for Stemborer and Striga Control, and improvement of soil fertility

H3C

H

H

H

(E)-4,8-dimethyl-

1,3,7-nonatriene

-caryophyllene (E)-β-ocimene

humulene

α-terpinolene

α -cedrene

hexanal

O

(E)-2-hexenal

O

(Z)-3-hexen-1-olOH

(Z)-3-hexen-1-yl acetate

O

O

0

20

40

60

80

100

120

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75

Days after egg hatch

% L

arv

al

surv

ival

Ex-Nyanza-1

Clone 13

Bana

Ex-Machakos

Ex-Nyanza-2

French Cameroon

Gold Coast

Mott

Pakistan Hybrid

Uganda Hairless

Maize

Survival of Stemborer (Chilo partellus) on

maize and Napier grass varieties

Khan et al. 2006. Entomol. Exp. Applic. 119:15-22

Stemborer larval feeding on Napier grass

Stemborer larvae trapped in gummy substance

Larva

Gummy substance

10 15 20 25 30

Pennisetum purpureum

Zea mays

1

2

3

GC of the volatiles from Napier grass and maize

during beginning of the scotophase

Retention time

I.S.

I.S.

Hexanal

(Z)-3-hexen-1-ol

(Z)-3-hexenyl acetate

Chamberlain, Khan, Pickett, Toshova and Wadhams, 2006. Journal of Chemical Ecology 32:565-577

Maize

Pull and trap P

ull an

d trap

Pull

and t

rap

Pull and trap

CONTROL OF STEMBORERS WITH TRAP PLANTS

Desmodium intercrop

• Inhibits striga growth through allelopathy

•Perennial fodder legumes indigenous to South America

•Important cattle feed in eastern Africa

•Can fix~ 110-160 Kg N/ha/year

Desmodium uncinatum Desmodium intortum

Long Term Trials with Maize-Legume Intercrops

Maize + Green gram

Maize + cowpea Maize +Desmodium

Maize + Beans

Khan et al. 2007. Crop Science 47:730-734

HYBRID MAIZE WITH FERTILIZER FOR 10 YEARS

fertilizer application alone is ineffective against striga,

the main biotic constraint to smallholder agriculture in

Africa

Khan et al. 2002. J. Chem. Ecol. 28: 1871-1885

ALLELOPATHIC MECHANISM OF STRIGA

SUPPRESSION

Compounds Isolated from Desmodium Root Exudate

Tsanuo et al. 2003. Phytochemistry 64: 265-273

Hooper et al. 2009. Pest Manag.Sci 65: 546-552

II. OUTCOMES

Push-Pull Strategy

1= (E)-ß-ocimene;

2= α-terpinolene;

3= β-caryophyllene;

4= humulene;

5= (E)-4,8-dimethyl-1,3,7-

nonatriene;

6= α-cedrene;

7= hexanal;

8= (E)-2-hexenal;

9= (Z)-3-hexen-1-ol;

10= (Z)-3-hexen-1-yl acetate ;

11= 5,7,2′,4′-tetrahydroxy-6-(3-

methylbut-2-enyl)isoflavanone

(uncinanone A);

12= 4′′,5′′-dihydro-5,2′,4′-

trihydroxy-5′′-isopropenylfurano-

(2′′,3′′;7,6)-isoflavanone

(uncinanone B); 13= 4′′,5′′-

dihydro-2′-

methoxy-5,4′-dihydroxy-5′′-

isopropenylfurano-(2′′,3′′;7,6)-

isoflavanone (uncinanone

C), 14= di-C-glycosylflavone 6-

C-α-L-arabinopyranosyl-8-C-β-

Dglucopyranosylapigenin

Before After •Effective control of stemborers

and striga weeds

•Grain yields increased from

<1t/ha to 3.5t/ha with minimum

inputs

•Soil health improved: nitrogen

fixation (110kg N/ha), increased

organic matter , moisture

conservation and enhanced soil

biodiversity

•Lower soil temperature –

improved potential to mitigate

effects of climate change

MAIZE INTERCROPPED WITH DESMODIUM MAIZE ONLY

Desmodium effectively inhibits Striga emergence;

raises maize yields from < 1 t/ha to 3.5t/ha

3.5 t/ha < 1 t /ha

On-Farm Evaluation of ‘Push-Pull’

Technology (n=420)

Khan et al. 2008. Field Crops Research 106: 224-233

5

10

15

20

25

0

100

200

300

400

500

0

1

2

3

4

2003 2004 2005 2006

30

No. of emerged striga/63 maize plants

% stemborer damaged plants

Maize Yields (t/ha)

*

****

****

** *

Maize monocrop fields

Push-pull fields

Economics of the push-pull system

-1

0

1

2

3

4

Trans Nzoia Suba Bungoma Busia

-200

0

200

400

600

800

1000

Retu

rn t

o l

ab

ou

r (U

SD

/man

day)

Return to Labour

Gro

ss b

en

efi

ts

(US

D/h

a)

Gross benefits

Push-pull system Maize/bean intercrop Maize mono

Districts

*Data averages of five years in each district

Khan et al. 2008. Crop Protection 27: 976-987

Sorghum Mono Crop Sorghum + Desmodium intortum

SORGHUM

2.6

t/ha 1.4

t/ha

MILLET

417

kg/ha

864

kg/ha

RICE

0

5

10

15

20

25

30

35

40

45

About a quarter About half About three quarters Almost all

Farmers' estimation of crop loss

% F

arm

ers

Benefits of Push-Pull Technology

Sustainable Development

Gender & Social Equity

Stemborers

and striga

control

Increased

fodder

production

N-fixation

and reduced

soil erosion

Increased

forage seed

production

Conservation

of biodiversity

Increased

crop yields

Improved

cattle

health

Improved

soil health

Increased

household

income

Technological

Empowerment of farmers

Improved

human health

Empowerment

of women

Improved

dairy

production

Improved

FYM

Production

III. KEY FACTORS FOR

HIGHER PRODUCTIVITY,

GREATER RESILIENCE AND

EXPANSION

Crop-Livestock Integration

Both trap and repellent plants are excellent livestock fodder.

Heifer International recommends push-pull as a source of

quality fodder for dairy animals

INTEGRATING BEANS IN PUSH-PULL SYSTEM

Maize and beans in different holes Maize and beans in same holes

Farmers’ Practice of planting Maize and

beans

Adaptation of Push-Pull to Climate

Change

Brachiaria cv mulato

Vetiver grass

Screening for drought tolerant grasses for use as trap

plants in adapted push-pull for drier areas of Africa

D. ramosissimum

D. intortum D. incanum

Identification of drought tolerant Desmodium spp.

D. repandum

Elucidation of scientific mechanisms of selected trap and

intercrop plants

H

H

(E)-ocimene (E)-4,8-dimethyl-1,3,7

-nonatriene

-caryophyllene humulene

-terpinolene

CHO CHO

MeO HO

MeO

OH

nonanal

4-allylanisole

naphthalene

octanal

eugenol

linalool

Plant volatile collection, analysis

and identification

CLIMATE-SMART PUSH-PULL

Farmers’ drama

Evaluation of Efficiency

and Economics of

Dissemination Pathways

Field days Print Media

Farmer Field Schools

Farmer Teachers

Radio

Key Elements of Processes that Build agro-

ecosystem Outputs and Resilience

•Use of locally available natural resources to increase farm

productivity, while delivering ecological and economic

benefits to smallholder farmers

•Polycultural system fits traditional farming systems, attracts

higher arthropod abundance and diversity

•Stemborer and striga control through plants natural

chemistry resulting in higher yields of cereal grain, fodder

and milk, and incomes

•Pereniality of companion plants ensures continuous striga

depletion

•Adaptability to climate change

•Environmental benefits: soil and moisture conservation,

improved soil health, increased soil cover and organic

matter, eliminates pesticide usage

GREEN REVOLUTION IN AFRICA ?

Productivity revolution in Africa will come from adoption of simple, environmentally sustainable and low cost platform technologies like push-pull, which are developed by understanding and exploiting basic and applied sciences. These technologies will address food security and livelihood of smallholders without requiring extra resources for crop protection and soil improvement and without causing any ecological and social harm.

RECOMMENDATIONS

• Institutionalisation, capacity development and scaling up Push-pull through continent-wide, regional and country-level partnerships in line with the CAADP Framework (FARA, ASARECA, AFAAS, EAFF, NAREs, and NGOs);

• Farming systems approach – Participatory validation, optimization and development of recommendation domains for different agro-ecological and country settings;

• Value chain development – building forward and backward linkages for sustainable application and integration of Push-pull.

THANK YOU

Agricultural innovation for their better future ..….