2 Soo-Hyung Kim - Kofikuma Dzotsi - Matthijs …...Three models were used: Hybrid Maize (Haishun...
Transcript of 2 Soo-Hyung Kim - Kofikuma Dzotsi - Matthijs …...Three models were used: Hybrid Maize (Haishun...
Dennis Timlin1 - Soo-Hyung Kim2 - Kofikuma Dzotsi3 - Matthijs Tollenaar4 - Saratha Kumudin4 - Haishun Yang5 - Gustavo Maddonni6 -Jon Lizaso7- David Fleisher1 - François Tardieu8 - Armen Kemanian9 - Bruno Quebedeaux10 - Kenneth Boote3 - Claudio Stockle11 1USDA-ARS, Beltsville, MD , 2University of Washington, Seattle, WA, 3Univ. of Florida, Gainesville, FL, 4Monsanto Corporation, Research Triangle Park, NC, 5Univ. of Nebraska, Lincoln, NE, 6Cátedra de Cerealicultura Fac. Agronomía. UBA, 7Fitotecnia, Technical Univ. Madrid, Spain, 8INRA, Montpellier, France, 9Penn State Univ. State College, PA, 10Univ. of Maryland, College Park, MD, 11Washington State Univ., Pullman, WA
Crop models are being used as tools to assess climate change impacts primarily through temperature and water stress effects
It is therefore important to accurately estimate leaf area expansion and senescence, and their linkage to leaf ontogeny and phenology particularly when average temperatures are above the optimum.
Investigate and assess different approaches to modeling leaf expansion in maize.
Investigate the effects of plant population on leaf expansion.
Three models were used:
▪ Hybrid Maize (Haishun Yang, Univ of Nebraska)
▪ AgMaize, (Kofikuma Dzotsi, Jon Lizaso, Thijs Tollenaar, and Saratha Kumudini, AgMIP)
▪ MaizSim, (Soo-Hyung Kim, Dennis Timlin, and David Fleisher, Univ. of Washington and USDA-ARS)
Relationship between maximum area of the leaf and node position (Stewart and Dwyer, 1994)
Area of any one leaf is proportional to area of largest leaf The proportionality factor is a function of leaf node position
Relationship between leaf longevity and node position (Lizaso et al., 2003)
There are commonalities to the simulation methods. These include:
Leaf area expansion can be based on the rank of the leaf and relative placement on the stem.
Potential growth rate and longevity are modeled as a function of temperature.
Leaf sizes can be modeled relative to the size of the largest leaf.
CO2 is fixed. Overall, LAI simulation is based on a combined
scheme of CERES-Maize, typical Wageningen models (e.g., WOFOST), and APSIM: Individual leaf growth is simulated. Leaf area calculated on
a plant basis as it is incremented area and increased by the number of leaf tips appearing on a given day.
Temperature determines daily potential leaf area expansion, parameters depend on growth stage.
Photosynthate availability and water stress regulate final daily LAI increase (or senescence after silking).
Leaf addition is by GDD (linear).
Other settings: Location: Mead, Nebraska Year: 2012 Planting: May 1 Maturity: RM 105d Water: fully irrigated
Pop=80k/ha
Pop=60k/ha
0
0.1
0.2
0.3
0.4
0.5
0.6
0 5 10 15 20 25 30 35 40 45
Ra
te o
f le
af
ap
pe
ara
nce
(le
ave
s/d
ay
)
Average air temperature (degree C)
TCeil
LTAR
bopt
R
TTnPhyllochro
max_
Topt
Tb=8
Rmax_LTAR
optceil
opt
TT
T
optoptceil
ceil
T
T
TT
TT
Tb= 0 OC Topt = 31 OC Tceil = 44 OC
(a) Leaf initiation
Mean ambient temperature (C)
10 20 30 40
Prim
ord
ia d
-1
0.0
0.2
0.4
0.6
0.8
1.0
1.2Warrington & Kanemasu
(1983b)
Line fit using data from SPAR chambers
(b) Leaf appearance
Mean ambient temperature (C)
10 20 30 40
Lea
ve
s d
-1
0.0
0.1
0.2
0.3
0.4
0.5
0.6Tips
Ligules
LeavesInitiated += beta_fn(T_cur, Rmax_LIR, T_opt, T_ceil);
0
5
10
15
20
25
0 5 10 15 20 25
Le
af
tip
s o
r le
af
lig
ule
s
TLU
Leaf ligules
Leaf tips
Duration of leaf-area expansion
For each individual leaf, the time of leaf tip (A) and collar (B) appearances expressed in thermal leaf unit are calculated.
Individual leaf expansion occurs linearly between these two points A and B.
Leaf longevity is calculated to determine when senescence should start (point C).
Senescence occurs between points C and D.
Maximum area of a leaf is a function of its rank and area of largest leaf.
Daily mean temperatures are used.
y = -0.0019x2 + 0.0967x - 0.2818 R² = 0.8563
y = -0.0041x2 + 0.1977x - 1.4631 R² = 0.8804
y = -0.0051x2 + 0.2249x - 1.5504 R² = 0.8591
0
0.2
0.4
0.6
0.8
1
1.2
0 5 10 15 20 25 30 35
No
rma
lize
d le
af
are
a
Mean temperature (oC)
4 leaf stage
8 leaf stage
12 leaf stage
Individual leaf growth and senescence are calculated
Maximum potential size is a fraction of the largest leaf dependent on the leaf rank.
Leaf addition and leaf appearance have separate parameters.
Leaf expansion, addition and appearance calculated using hourly temperature, rates determined using a beta function.
Based on Lizaso et al. (2003) and Fournier and Andrieu (1998) but does not use directly use GDD
Leaf expansion parameters are adjusted by hourly growth temperature.
Lizaso et al., 2003
)(
12
Tfe
ekeA
dt
dA
ii
ii
tetke
tetke
ieii
)(
12
Tfe
ekeA
dt
dA
ii
ii
tetke
tetke
ieii
ke is an intrinsic growth rate that depends on leaf number te is leaf longevity and depends on leaf number Aei is the final optimum area of the leaf at rank i
pk
b
pk
b
T
TT
T
TTTf 0.1exp,0.0max)(
(A)
Temperature (oC)
10 15 20 25 30 35
Re
lative
fin
al le
af a
rea
0.0
0.2
0.4
0.6
0.8
1.0
1.2
(B)
Temperature (oC)
10 15 20 25 30 35
Rela
tive
te
0.5
1.0
1.5
2.0
2.5
Re
lative
ke
0.2
0.4
0.6
0.8
1.0
1.2
Whole canopy (Kim et al., 2007; Bos et al., 2000; Tollenaar, 1989) and individual leaves (Hesketh and Warrington, 1989; Fournier and Andrieu, 1998);
Ke (◦) is slope of the leaf growth rate
te (●)is the number of GDD (base 8) for a leaf to reach 50% of its final size (both parameters are from Jon Lizaso’s paper). Data are from Beltsville SPAR experiments
Five site years of Maize harvests from the Eastern Shore of Maryland, Wye, MD – 2006 2007 and 2008
Georgetown Delaware – 2006 and 2007, irrigated Weekly to bi-weekly destructive harvests and
measurement of plant phenology, leaf area Average growing season temperatures range
from 19 to 23C Minor to no water stress during leaf
expansion
Beltsville
Wye
Georgetown
Hybrid Maize
No calibration was performed
AgMaize
Leaf senescense rate, and maximum area and node position of largest leaf calibrated.
MaizSim
Maximum juvenile leaf number.
MD, 2006
0 20 40 60 80 100 120
2000
4000
6000
8000
10000MD, 2007
0 20 40 60 80 100 120
Leaf surf
ace a
rea, cm
2 p
lant-1
MD, 2008
Days after emergence
0 20 40 60 80 100
DE, 2006
0 20 40 60 80 100 120 140
2000
4000
6000
8000
10000DE, 2007
0 20 40 60 80 100 120
MD, 2006
0 20 40 60 80 100 120 140
2000
4000
6000
8000
10000MD, 2007
0 20 40 60 80 100 120 140
Leaf surf
ace a
rea, cm
2 p
lant-1
MD, 2008
Days after emergence
0 20 40 60 80 100 120 140
DE, 2006
0 50 100 150 200
2000
4000
6000
8000
10000DE, 2007
0 50 100 150 200
MD, 2006
0 50 100 150
2000
4000
6000
8000
10000MD, 2007
0 56 112 168
Leaf surf
ace a
rea, cm
2 p
lant-1
MD, 2008
Days after emergence
0 50 100 150
DE, 2006
0 50 100 150 200
2000
4000
6000
8000
10000DE, 2007
0 50 100 150 200
HybridMaize MaizSim AgMaize Obs
Wye 2006 4.9 4.1 4.0 4.1
Wye 2007 4.9 3.9 4.0 4.3
Wye 2008 4.3 3.2 3.6 3.5
Collins 2006 5.4 4.1 4.2 4.2
Collins 2007 5.1 4.2 4.2 4.7
Treatment
LAI
Model
AgMaize HybridM MaizSim
Normal 3.9 5.1 3.9
Normal Avg +3 3.8 5.0 3.7
Normal Avg +6 3.4 5.0 3.4
Treatment
Anthesis Date Maturity Date
Model Model
AgMaize HybridM MaizSim AgMaize HybridM MaizSim
Normal
188.2 193.2 193.6 238.2 242.0 244.4
Normal Avg
+3 178.4 181.0 185.8 222.4 221.6 226.2
Normal Avg
+6 172.0 171.8 180.2 211.4 207.4 214.4
Senescence Impact of stresses
Impact on photosynthesis Plant density effects
Reflects carbon vs. expansion linkage
Light quality relationship
Increasing density can be considered to cause light or carbon stress
VPD vs temperature as a driver for leaf expansion as proposed by Francois Trudeau.
Plant density affects both the quality and quantity of light absorbed by individual leaves
The ratio of shaded to sunlit leaves increases as population increases
There is a change in the ratio of red to far-red light and this impacts leaf growth and photosynthesis
Leaf expansion rate can be adjusted based on the ration of sunlit to shaded leaf fraction
Zhu et al., 2014. Early competition shapes maize whole-plant development in mixed stands. J Exp. Botany. 65:641-653 Here maize was intercropped with wheat. This appears to correspond to the sunlit/shaded leaf fractions and plant population.
Senescence is too slow
We presented three approaches to modeling leaf area in maize
Two models used actual temperatures and employed a non-linear function to calculate temperature effects on leaf addition and expansion
One model used a GDD approach, two models used temperature directly.
All three approaches were able to realistically simulate observed leaf addition rate and leaf area.
Leaf addition rate from growth chambers as a function of temperature seems stable over a wide variety of hybrids. Thus some factors may be general and not have to be calibrated for most situations.
Some calibration/fitting may be necessary to obtain optimal parameters for leaf area expansion for a particular variety. Size of largest leaf and location on the stem is one
of the most critical variables
Total number of juvenile leaves Methods to realistically estimate effects of
temperatures above the optimum are necessary but data for testing may be hard to find.
Role of carbon and leaf water potential Look at plant population effects (carbon effect) Light intensity from growth chambers Carbon interaction with temperature - SLA
Vapor pressure deficit effects on growth even under optimal nutrient and soil water.
Nitrogen effects. How to address interactions such as between
nitrogen and water, or temperature and nitrogen.
Application to tropical varieties.