Agroecological approaches to breeding

Agroecological Approaches to Breeding
Professor Len Wade, lwade@csu.edu.au. Graham Centre, Charles Sturt
University, Wagga Wagga, NSW 2650 Australia
International Symposium on Agroecology for Food Security and Nutrition
FAO Rome, 18-19 September 2014
SCHOOL OF AGRICULTURAL & WINE SCIENCES

Content
Crop and system design for improved
agroecological fitness
Sustainable intensification, ecosystem services,
and food and nutrition security
Competition for resources and their allocation in
contrasting agronomic systems including
monoculture, mixtures, and with livestock
Implications for breeding targets, selection, proof of
concept

Monoculture
Define growing season – start, end, resources
Phenological pattern for performance and stability
Key traits needed for major biotic and abiotic stress
Effective phenotype with stable performance
Sample or create diversity, select, test, release
New crop – evaluate and release
Major crop – full breeding program

Agroecological Principles for Monoculture
Resources are finite, capture when available
Need to understand system dynamics for
replenishment of available resources
Issue of competition and phenotype expression
e.g. wheat
Early generation spaced plants
vs. advanced generation sward
Recognise need for a different plant type for
success in each system

a)
70
60
50
40
30
20
10
0
Leaf Area (cm2)
Yagan
Hamelin
Baudin
b)
70
60
50
40
30
20
10
0
Leaf area (cm2)
c)
70
60
50
40
30
20
10
0
MS T1 T2 T3 T4
Leaf area (cm2)
Figure 4. Leaf areas for individual tillers of Yagan, Hamelin and Baudin grown in a controlled
environment room for 39 days at plant densities of: (a) 1 plant/pot, (b) 3 plants/pot and
(c) 5 plants/pot. (O’Callaghan 2006)

a)
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Dry Weight (g)
Yagan
Hamelin
Baudin
b)
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Dry Weight (g)
c)
1.4
1.2
1
0.8
0.6
0.4
0.2
0
MS T1 T2 T3 T4 T5 T6 T7 T8 ST TT
Dry Weight (g)
Figure 6. Dry weights at 62 days of main stem, individual primary tillers, all secondary tiller and all tertiary
tillers, at: (a) 1 plant/pot, (b) 3 plants/pot and (c) 5 plants/pot. (O’Callaghan 2006)

Competition in Monoculture-based Crop
Aim to minimise inter-plant competition in like
sward
But for competitive advantage vs. weeds, may
select more competitive types, with high
projected LAI, e.g. Mahsuri rice
Leads to considerations of architectural design for
intercrops, e.g. maize-peanut
Consider concepts,
then look at examples

In a Mixture look for Mutual Advantage
Contrasting architecture or time sequence
Access resources from different zones
One partner with special attribute to help other
e.g. P acquisition, N fixation, deep roots
Commensualism and helping each other
Include perennial crops in diverse systems
e.g. Wade 2014 in FAO Workshop

Mixtures with Multiple Roles
Intercrop or relay cropping:
harvest one for grain then the other later,
or graze now then allow to set grain later etc.
Role for trees, growth patterns offset, resources
drawn from different layers at different times
Grazing with provision of supplements e.g. hay,
silage, molasses/urea, salt, water
Pasture with regular livestock grazing

Perennial Grass and Annual Forage Legume
A B
A. A mixed forage pasture sward containing a perennial grass (Phalaris
aquatica) and self-regenerating annual legume species (Trifolium
subterraneum, T. michelianum and T. glanduliferum)
B. Gland clover (T. glandiferum); A self-regenerating annual forage legume
released commercially in Australia for its superior insect pest resistance
Hayes et al 2014

(a) Permanent perennial grain crop
polyculture
(b) Perennial cereal- annual legume mixture
(c) Relay or companion cropping into
perennial cereal
Depictions of alternative
farming systems involving
permanent perennial cereals
Bell 2014

Year 1 -3 – Perennial cereal phase
Grain legume Cereal or non-legume
crop
Legume pasture
Rebuilding soil N and water reserves
Creating dry soil buffer
Years 4-6 – Annual crop phase
Wet soil
Dry soil
(d) Phase perennial crop-annual crop/pasture rotation
Bell 2014

Pigeon peas provide intercropping opportunities for farmers. Because of their
slow growth rates in the first year, they do not compete aggressively with
faster growing legumes such as groundnuts. As they regrow in the second
season, they can compete with more aggressive crops such as maize.
Snapp 2014

Intercropping of pigeon pea and groundnut
Taller, slower growing pigeon peas complement lower- and faster-growing
groundnuts, which are ready for harvest several weeks before pigeon peas
mature
Glover 2014

Shrubby pigeon pea intercrops (SP-Intercrop) and shrubby pigeon pea rotations
(SP-Rotation) decrease fertiliser requirements; improve the value cost ratio
(VCR), fertiliser use efficiency, and protein yields; increase carbon and nitrogen
assimilation and phosphorus availability; and provide greater cover than
monoculture maize Snapp 2014
Resource Efficiency

Ecological tradeoff for seven different crop rotations as cropped land in
Watonwan County, Minnesota, is changed from 100% prairie to 100% of
each of the different crop rotations
corn-pennycress
-wheat
Curves indicate the tradeoff between relative sediment loss and relative
economic value of each rotation (Runck et al 2014)
Ecological consequences
soy-wheat
bare
soil
corn or corn-soy

Ecosystem services under 3 land-use regimes
Reganold 2014
Transformative Systems

Coconut-oil palm-crop
Muhammed and Serkan 2014

Faidherbia albida – Zea mays
Maize understory while tree is dormant
Maize in wet season, forage in dry season
Dixon & Garrity 2014
[Also mention Leakey 2014 – participatory agro-forestry]

Issues for Selection in Mixed Systems
Need to evaluate together in target systems
Must be managed in accord with intended use
Evaluate not individually, but by combined benefits
Successful phenotype for mixture may not be best
individually, e.g. like spaced vs. sward plants

Issues of Co-Evolution and Joint Selection
Species for grazing evolved with their grazer
Plants developed adaptations to allow them to be
grazed but still survive and reproduce, e.g.
growing points sheltered in grasses
Animals adapted mouthparts, digestive flora in gut,
tolerance to certain plant chemicals, foraging
ability
Co-evolution in natural environments as a model
for selection in managed environments

Improvement in a Co-Evolutionary Context
Seek plants with improved capture of resources,
better survival and growth under stress and
grazing
Animals with greater growth efficiency, better
foragers, able to move, reproductive success
Management changes to assist – availability of
water, supplement for supporting young,
provision of shelter
Issue is system performance and resilience

Used examples from diverse systems
Annuals, perennials, mixtures, perennial crops
Need to develop and include perennial crops for
improved system performance and stability
Underused crops
Tef, Setaria and short duration grasses and grains
Sunflower esp. wild types; Lepidium (field cress)
Bambatse groundnut, other pulses, Trees
Select from germplasm vs. full breeding program

Conclusions
Challenges in mixtures, especially with livestock
– more complex
But similar principles apply
Understand characteristics of target population of
environments
Select for systems performance and stability
Care for agroecosystem fitness, system sustainability,
system intensification, ecosystems services, food
security and nutrition
Requires systems understanding – environmental health,
resource dynamics, resilience, sustainable
performance

Reference
Batello C, Wade LJ, Cox TS, Pogna N, Bozzini A,
Chopiany J 2014. Perennial Crops for Food
Security. Proceedings of the FAO Expert
Workshop, FAO, Rome, Italy 390pp
Acknowledgements
Many colleagues for useful discussions

Mean overlap of flowering periods of native legumes at
Seton, MB, for 2010-2013
Astragalus agrestis Douglas ex G. Don
Vicia americana Muhl. ex Willd.
Pediomelum esculentum
Dalea purpurea Vent.
Oxytropis splendens Douglas ex Hook.
Lathyrus ochroleucus Hook.
Dalea candida Michx. ex Willd.
120 140 160 180 200 220 240 260
Day of the Year
Cattani 2014
Polyculture example

Diagrammatic
representation of
the cycle of land
degradation and
associated
social
deprivation
Leakey 2014

Diagrammatic
representation of
multifunctional
agriculture and its
goals
Leakey 2014

Diagrammatic
representation
of how the
three steps to
close the yield
gap impact on
food security,
poverty and
livelihoods
(sustainable
intensification)
1 = Improved
fallows (N fix)
2 = Particip
domestication
3 = Value add
and process
Leakey 2014

Agroecological approaches to breeding

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