First Africa Congress on Conservation
Agriculture
Lusaka, ZAMBIA
18-21 March 2014
Climate-smart push-pull: A conservation
agriculture technology for food security and
environmental sustainability in Africa
Zeyaur Khan1, John Pickett2, Charles Midega1 and
Jimmy Pittchar1
1International
Centre of Insect Physiology and Ecology, Nairobi, Kenya
2Rothamsted Research, Harpenden, United Kingdom
www.push-pull.net
HUNGER AND
POVERTY IN
AFRICA
• Africa faces increasingly serious problems in its ability to
feed its rapidly growing population, resulting in high
hunger and poverty incidences.
• Africa’s productivity is the lowest in the world (around
1t/ha compared with 2.4t/ha in South Asia, 3.2t/ha in Latin
America and 4.5t/ha in East Asia and Pacific)
• The major production constraints are pests, weeds and
degraded soils.
• Ecologically sustainable growth in agricultural productivity
is essential to end hunger and poverty and ensure food
security, by naturally reducing incidence of the major
constraints to productivity
Chilo partellus
Busseola fusca
Maize worth US$ 1.5b is lost annually due to stemborers in
SSA
24% of the total maize cropping area in SSA is infested with
Striga. Value of maize lost due to Striga is at least US$ 1.2 b
What is ‘Push-Pull’ Strategy?
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.
Main Crop
Trap Crop
Attract moths
Attract natural
enemies
Moths are
pushed away
Cook, Khan and Pickett (2007) Annu. Rev. Entomol. 52 : 375-400
Push-Pull Strategy
1= (E)-ß-ocimene;
2= α-terpinolene;
3= β-caryophyllene;
4= humulene;
5= (E)-4,8-dimethyl-1,3,7nonatriene;
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-(3methylbut-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 6C-α-L-arabinopyranosyl-8-C-βDglucopyranosylapigenin
Benefits of Push-Pull Technology
Sustainable Development
Gender & Social Equity
Technological
Empowerment of farmers
Stemborers
and striga
control
Increased
fodder
production
Increased
crop yields
Improved
cattle
health
Improved
dairy
production
Improved
FYM
Production
Improved
human health
N-fixation
and reduced
soil erosion
Increased
forage seed
production
Conservation
of biodiversity
Increased
household
income
Improved
soil health
Empowerment
of women
NITROGEN FIXATION WITH VARIOUS
INTERCROPS AFTER THREE YEARS
0.25
Total N (g) / 250 g Soil
a
0.2
0.15
b
b
b
b
0.1
0.05
0
Maize Monocrop
Maize +
Desmodium
Maize + Soybean Maize + Sunhemp
Intercrops
Khan et al. 2006. Biological Approaches to Sustainable Soil Systems, CRC Press
Maize + Cowpea
On-Farm Validation of ‘Push-Pull’
Technology (n=420)
30
% stemborer damaged plants
Maize monocrop fields
Push-pull fields
25
20
15
*
10
*
500
*
*
5
No. of emerged striga/63 maize plants
400
300
200
*
100
0
*
*
*
Maize Yields (t/ha)
4
3
*
*
2
*
*
1
0
2003
2004
2005
2006
Khan et al. 2008. Field Crops Research 106: 224-233
Integration with livestock
Integrating push-pull with livestock production
Adaptation of Push-Pull to Climate
Change
With funding by
European Union,
we have adapted
the push-pull
technology to the
increasingly dry
and hot
conditions
associated with
climate change
in Africa to
ensure its long
term
sustainability.
SELECTION OF NEW DROUGHT
TOLERANT COMPANION PLANTS
Brachiaria cv mulato
Desmodium
intortum
Vetiver
grass
Screening for drought tolerant companion plants for use
in adapted push-pull for drier areas of Africa
Research into New drought tolerant African Desmodium spp.
D. incanum
D. repandum
D. ramosissimum
CLIMATE-SMART PUSH-PULL
A healthy sorghum crop under climate-adapted push-pull. D. intortum suppresses striga
and stemborers by up to 100% and 70% respectively in sorghum, resulting in significant
yield increases, from less than 1t/ha to about 3.2t/ha.
CLIMATE-SMART PUSH-PULL
Increased yield as striga and stemborer controlled
in sorghum and millet
4000
Yield, Kg/ha
3000
2000
1000
0
Adapted
Push-Pull
Control
Maize plot
Adapted
Push-Pull
Control
Sorghum plot
First season on-farm results of maize and sorghum yields from push-pull plots
planted with the drought tolerant companion plants: Brachiaria c.v.Mulato II as
the trap plant and Greenleaf desmodium as the intercrop plant.
Farmers’ Perceptions of ADOPT
Push-pull Technology Adoption
About 18,000 of the adopters planted climate-adapted
push-pull by December 2013
Climate-smart push-pull addresses multiple constraints
Major constraints
How Push-pull addresses Constraints
Low soil fertility
Increased nitrogen fixation by the intercrop
Degraded land
Control soil erosion; increased organic matter and soil physical
properties
The parasitic striga
weed
Striga control by the intercrop, striga seed depletion
Stemborer pests
Effective stemborer control by companion plants, and natural
enemies
Moisture stress
Soil moisture conservation, improved water holding capacity by
intercrops
Low crop yields
Increased cereal yields (maize from 1 to 3.5t/ha; sorghum 0.8t to
2t/ha; millet 0.4t to 0.8t/ha)
Shortage of livestock All year round quality fodder from the trap and intercrop plants
fodder
leading to improved milk production
Loss of biodiversity
Increased abundance and diversity of beneficial organisms
Shortage of labour
Reduced labour requirement for land preparation and weed
control
Developing long term
sustainability and system
resilience
•We make the best use of locally adapted crop varieties and
livestock breeds through their management;
•We harness agro-ecological processes such as biological
nitrogen fixation, allelopathy, predation and parasitism;
•We avoid the unnecessary use of external inputs;
•We minimise the use of practices that have adverse
impacts on the environment and human health;
•We make productive use of human capital - knowledge and
capacity to adapt and innovate as well as social capital to
resolve common landscape-scale problems.
Sustainable Green Revolution in Africa ?
A green 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.
THANK YOU
Conservation methods for better livelihoods, better future…