Adel-maize and Adel wheat
as tools for simulating the
dynamics of 3D canopies
Bruno Andrieu and Christian Fournier
INRA, UMR EGC
78850 Thiverval-Grignon
[email protected]
[email protected]
Why models of plant architecture ?
• Component of FSPMs
• Tools to simulate the time curse of 3D
canopy structure
– Modelling the environment perceived by
individual plant organs
– Improving prediction of statistical variables
• Intermediate approachs : eg 3D models
interfaced with crop models
Specific aspects
• Kinetics of development, extension and
senescence of individual plant organs
• Patterns of size of mature blade,
sheaths, internodes
• 3D geometry
– Leaf geometry and orientation
– Axe orientation
Adel-maize
Scheme of development
Rank of the Phytomer
Schedule of organ extension
18
15
12
9
6
3
0
0
300
600
Thermal time (°Cj)
900
Area of the laminae (cm²)
Size of mature leaves along the
shoot
1200
1000
800
600
400
200
0
0
10
20
Phytomer number
30
Parametrisation of midrib
curvature
cx²+dy²+e=0
Ax²+bx
Phi ?
Prévot et al, 1991
Measured vs simulated light
interception
Taux de couverture
,
,
,
,
,
Indice foliaire
B. Andrieu, G. Popa, Y.
Sohbi, C. Fournier
Exemple of application
•A field experiment was reproduced in silico, enabling incident PAR to
be calculated for all individual leaf
15
1
F4 à F6
F7 à F9
10
f(E)
F10 à F13
f(n)
Final width of all laminas
above 4 could be interpreted
as the product of two simple
functions : Wmax = f(n) *f(E)
F14 à F16
0,139*log
(E/14,3414)
0,5
5
0
0
0
5
10
15
0
10000
f(n)
20000
30000
Cumulated flux (KJ/m²)
Phytomer
f(E) # ln(E)
•Thus response of width of lamina to density appear to be a
function of local light availability.
40000
In progress
• Ability to simulate a range of contrasted
genotypes
• More generic description of leaf geometry
• Investigation on plasticity of architecture
under contrasted environmental conditions
(density, cold).
Still far from mechanistic simulation
But good progress in identifying the degree of freedom
Wheat architecture
f8 f7
f11
f7
f 12
f8
f9
f6
f7
f6
f8
PHYTOMERE
Entre-nœud
T1
T1
T0
D 250
Feuille
T0
Bourgeon axillaire
D 70
Size of matures laminae along
the shoot
D 70
D 70
35
35
bm
t1
t2
t3
t4
t5
t6
25
20
T0
T1
15
T2
T3
10
T4
T5
T6
5
0
Length of laminae (cm)
Length of laminae (cm)
30
30
25
20
15
10
5
0
0
1
2
3
4
5
6
7
8
Phytomer
9 10 11 12 13
0
1
2
3
4
5
6
7
8
9
10 11 12 13
Relative phytomer number
A unique shift applies to laminae, sheath and
internodes
Sheath D70
Entrenoeud D70
35
25
bm
t1
t2
t3
t4
t5
t6
15
25
L entrenoeud
Longuer(cm)
(cm)
length
20
bm
t1
t2
t3
t4
t5
t6
30
10
20
15
10
5
5
0
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13
0
1
2
3
4
5
6
7
8
Phytomere relatif
Relatif phytomer number
9
10 11 12 13
Kinetics of leaf extension
follows a single pattern along
the shoot
See also Fournier et al New Phytol 2005
Prevot et al (1991) maize leaf
fitted to wheat leaves
See also Fournier et al 2003 in PMA03
Evers et al, New Phytol 2005
In progress
• with UCL (J. Watt, J. Hillier, P. Lewis)
– Multi-genotype version
– Duration of leaves
– Use in Remote sensing
• With WUR (J. Evers, J. Vos)
– Extension to spring wheat
– Tillering
– Incorporating photosynthesis
After J. Watt
Blade length
Sheath length
Internode length
To be further investigated
• Still few is known about the quality of 3D
representation for RT investigations
– Tropism, shade avoidance <-> clumping
• How far can we decrease the number in
model parameters (due to low RT sensitivity,
or stable patterns)
– eg in describing leaf shape (in progress)
• Genericity over a range of genotypes,
species
Remaining to be modelled
• Distribution and time curse of leaf
exchange properties (Cab, H20, etc ..)
and death to drive a leaf reflectance
model
• How kinetics of extension and mature
size of organs is driven by environment
(H20, Nitrogen, density)
• Ear development and optical properties
In progress
• with UCL (J. Watt, J. Hillier, P. Lewis)
– Multi-genotype version
– Duration of leaves
– Use in Remote sensing
• With WUR (J. Evers, J. Vos)
– Extension to spring wheat
– Tillering
– Incorporating photosynthesis