Making the best of ‘variation’
Rosemary Collier
Warwick Crop Centre, School of Life Sciences
‘Evidence-based decision
support for food security’
15-17 April 2015
"Variety’s the very spice of life, that gives
it all its flavour."
William Cowper
My ‘theme’
• Food production is dependent on living organisms
and their responses to their environment.
• ‘Variation’ in these living organisms and their
environment offers both opportunities and challenges
to food producers.
• Impacts on efficient use of resources and waste.
Environmental variation
Climate and the weather!
Influence of the weather on ‘demand’
Influence of the weather on ‘supply’
Lettuce - UK industry indicated that there would be
a negative impact on quality following:
• Heavy rainfall
• High temperatures
• Low temperatures
• Differences in day/night temperature less than 8oc
• Can build mathematical models to describe relationships
Pests and diseases
Incidence very dependent on weather
Weather affects survival and rates of development
and reproduction - mainly through temperature and
‘wetness’
Late season
Again, can build mathematical
models
Decision support
Decision support – short term
Monitoring to predict pest
and disease incidence
Carrot fly
Ne4
Bo
u
nd
ary
1
Ne1
x1
N1
.
x4
n
u
Bo
x3
x2
ar y 2
Boundary 4
Ne2
r
da
y3
Ne3
nd
Bou
Single transect from edge of crop
50
45
No. flies per trap
40
log Nˆ m  log N e  log( (k ))  k log b  (k  1) log 0.1  0.1b
35
30
k=0.93, b=0.022
25
20
15
10
5
0
0
20
40
60
80
100
Distance from edge of crop (m)
120
140
160
mean distance travelled = 42.3 m
Decision support – short term
Using models and weather
data to predict pest and
disease incidence
Carrot fly
30
Forecast percent eggs laid per week
25
20
15
10
5
0
31-Mar
14-Apr
Cornwall
28-Apr
Kent
Lincolnshire
12-May
Lancashire
26-May
Scotland
9-Jun
Decision support – long term
night >14oC
day >28oC
100
Number of days when...
30
25
20
15
10
5
0
base
2020s
80
60
40
20
0
2050s
base
day >28oC & night >14oC
2050s
night <5 C
40
25
Number of days when...
Number of days when...
2020s
o
30
20
15
10
5
0
base
2020s
30
20
10
0
2050s
base
o
difference between day & night <8 C
120
Number of days when...
Using climate models to
provide weather data
Number of days when...
35
100
80
60
40
20
base
2020s
2050s
2020s
2050s
Potato harvest - UK
Using climate models to
provide weather data
© Etc food blog
25
Daily rainfall (mm)
20
Incidence of runs of 7 days with an
accumulated rainfall total of 10 mm
or greater between 1 August and
31 October
rain in 2000
National cumulative lifting % /10
15
10
5
0
1 Aug
1 Sep
1 Oct
1 Nov
1 Dec
25
15
Incidence
Daily rainfall (mm)
Rothamsted Hertfordshire
rain in 2003
National cumulative lifting % /10
20
10
5
80
80
60
60
40
40
20
20
Boulmer Northumberland
0
0
0
base
1 Aug
1 Sep
1 Oct
1 Nov
1 Dec
2020s
2050s
base
Timeslice
2020s
2050s
Number of generations of diamond-back moth
Using climate models to
provide weather data
base
2020s
2050s
Camborne Cornwall
Kirton Lincolnshire
Wye Kent
Leuchars Fife
2
3
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
2
3
4
5
6
7
150
moths
over-winter
first sighting
on 1 February
100
50
moths
migrate in
first sighting
on 1 May
Frequency of synthetic years
0
4
5
6
150
100
50
0
Camborne Cornwall
150
moths
migrate in
first sighting
on 1 June
100
50
0
Number of generations before either the first Autumnal frost or 31 December
Biological variation
Current commercial crop cultivars provide
uniformity and are grown in monocultures
• Ease of growing
• Consistent size and quality
• Ease and costs of harvest
Uniformity = vulnerability?
• All plants respond in same way
• Currently selected for high input conditions
(fertiliser, water, pesticides)
• In longer term may need ‘resilience’ – within
and between crops
• Genetic variation in wild hosts and old
varieties may be source of ‘resilience’
Pest and disease populations also genetically variable
• High selection pressure from
pesticides or host plant resistance
may lead to selective advantage for
individuals that can overcome them
• Evolutionary arms race…
• Modelling can help with
management
Mixtures - cultivars!
• “Mixtures of cultivars that vary for many
characters including disease resistance, but
have sufficient similarity to be grown together."
(Wolfe, 1985)
• No major changes to the agricultural system,
generally increase yield stability, and in some
cases can reduce pesticide use.
• May be similar for important traits including
maturity, height, quality and grain type.
Depending on the agronomic practices and
intended use.
American Phytopathological
Society
Mixtures - species!
• Used extensively in some parts of the world – especially
intercropping
• Maximises use of land – may get increased yield per hectare
• Spreads ‘risk’
• Other possible advantages
– Increased nutrient use efficiency
– Increase water use efficiency
– Weed suppression
– Pest suppression
– One crop ‘shelters’ another – provides better growing conditions
Pearl millet-Groundnut Source: ICRISAT
Source: ICIPE
Source: Organic Garden Info.com
Finger millet and sugar cane
Source: Bio-dynamic Association Of India
Agroforestry
•
•
•
•
•
•
•
•
3D farming!
Improved soil & water protection
Improved habitat
Multi-functional land use
Multiple crops & harvests – less risks?
Multiple market outlets
Wood – fuel bonus
Climate change mitigation
The future for evidence-based decision support for food
security!
• Long range weather forecasting?
Climate forecasting?
• GPS, GIS, precision farming –
planting, treatment, harvesting?
© US National Archives
• Genetics and genomics
• Plant, animal and environmental
science!
© Daddy’s tractor
With thanks to:
• Defra
• Horticultural Development Company
• My colleagues
The UK Vegetable Gene Bank @ Warwick