Using APSIM to Using APSIM to simulate crop-simulate crop-parasitic weed parasitic weed

interactionsinteractions

Plant Production and Plant Production and Agroecology of the Agroecology of the

Tropics and SubtropicsTropics and Subtropics

24.2.2005 – Dr. J. Grenz

contact: jangrenz@uni-hohenheim.de

Outline

•The Orobanche problem

•The Agricultural Production Systems Simulator

•Simulating Host-Parasite Interactions

•Applications of APSIM-Parasite

•Outlook

O. cumanaO. crenata

O. minorO. ramosa / O. aegyptiaca

Economically important Orobanche species

The Orobanche problem - 1

Orobanche crenata – crenate broomrape

• largest Orobanche species• common around the Mediterranean• mainly attacks Fabaceae, Apiaceae• yield losses from 5 to 100%

• individuals produce numerous highly persistent seeds

• yet no control method is sufficiently effective and practicableThe Orobanche problem -

2

•Specificity: only attaches to potential hosts

•Destructivity: grows fully at expense of the host

•Fecundity: individuals can produce more than 200,000 seeds

•Longevity: seeds can remain viable in the soil for more than 10 years

•Mobility: tiny seeds adhere to machinery, seeds, animals, …

Aspects of the Orobanche Problem

The Orobanche problem - 3

• Developed at the Agricultural Production Systems Research Unit, Toowoomba (Qld), Australia

APSIM simulates:• Growth and development of crops, pastures, trees, weeds• Key soil processes (water, N, P, carbon, pH)• Management options (tillage, sowing, irrigation,

fertilisation) • Surface residue dynamics• Soil erosion• Cropping systems• Rotations/fallowing/mixtures• Short or long term effects

The Agricultural Production Systems Simulator

APSIM - 1

more information @ www.apsru.gov.au

Crops

System Control

Soil

SWIM

ManagerReportClock

SoilWat

SoilN

SoilPH

SoilP

ResidueEconomics

Fertiliz

Irrigate

Canopy Met

Erosion

Maize

Sorg

Legume

Wheat

New Module

Manure

Management

ENGINEParasite

APSIM: plug-in-pull-out structure

APSIM - 2

•Key feature: effects of one crop on another passed on via the soil

Quantifying faba bean – O. crenata interactions

• Experiments in Syria (1993-95)...

... and Turkey (2000-02)

Host-Parasite Interactions - 1

DevelopmentGrowthFaba bean

Daily DM Production(PAR, Q, LUE, LAI)

DM Partitioning(Roots, Leaves, Stems,

Pods)

Senescence and Retranslocation

Rooting front, RLD, Senescence

Emergence

Pod setting

Seed filling

Physiological Maturity

Soil WaterDrainage, Evaporation,

Transpiration, Soil water content

Flowering

Leaves

Branches

Structure of the faba bean model

Host-Parasite Interactions - 2

DevelopmentGrowth O. crenata

Assimilatepool

Pods

StemsRoots

Leaves

Bud

Tubercle

Shoot emergence

Host maturity

Potential growth rate of an

O. crenata plant (Temp. sum)

Total number of attachments (RLD, O. crenata seed density)

DM O. crenata

Faba bean emergence

Appressorium

Structure of the parasite model

Host-Parasite Interactions - 3

The Cohorting Routine

11

Vegetative Crop Organs

Fruit Cohort Component

Physiological age

Parasite Module

Da

ily

pa

rasi

te c

oh

ort

s

Physiological age

1

2

3

34

PN = 8

. .

. .

. .

. .

. .

. .

. .

. .

. .

.

PN = 12

PN = 9

PN = 16

Da

ily f

ruit

co

ho

rts

1

2

12

. .. . . . . . . . .

FN = 60

FN = 28

FN = 12

CropModule

(biomasspool)

Physiological age

……

.

FN = 9

(I) (II)

(III)

(IV)

Leaf

Root

Stem

Host-Parasite Interactions - 4

•Seed production = f (parasite biomass)

•Seed survival = f (soil moisture)•Vertical distribution = f (tillage)

Cropping System

Crop

Crop Hos

tCr

op

HostCrop

Crop

Crop

CropOrobanche soil seed bank

The seedbank model

Host-Parasite Interactions - 5

Simulated (curves) and measured (points) leaf area index (LAI), shoot

(open circles) and pod biomass (closed circles) of faba bean grown

without Orobanche infestation in 1994-95; SD1 and SD2 indicate the

first (Nov. 7) and second (Dec. 12) sowing date, respectively.

Some calibration results

Host-Parasite Interactions - 6

Crop phenology

Crop biomass

Crop yield

Parasite biomass

Some evaluation results

Host-Parasite Interactions - 7

Single-season simulations

• faba bean cv. ILB 1814

• Weather records (1979-2000) from Adana and Tel Hadya

• 0 resp. 100 O. crenata seeds kg-1 soil (0-15 cm)

• 7 sowing windows:

Oktober January November December

22.10. 8.11. 22.11. 8.12. 22.12. 8.1. 22.1.

Optimal faba bean sowing windows

Model applications - 1

Results: Tel Hadya

17.6 °C 339 mm

200

400

600

800

1000

200

400

600

800

1000

0 0

pod

yie

ld (

g m

-

2) pod

yie

ld (

g m

-

2)

22-O

ct

8-Nov

22-N

ov

8-Dec

22-D

ec

22-Ja

n

8-Ja

n

22-O

ct

8-Nov

22-N

ov

8-Dec

22-D

ec

22-Ja

n

8-Ja

n

10

20

30

40

50

avera

ge t

em

pera

ture

(°

C)

tota

l rain

fall

(mm

)

20

40

60

80

100

non-infested

100 O. crenata seeds kg-1 soil

Model applications - 2

Results: Adana

18.8 °C 667 mm

200

400

600

800

1000

200

400

600

800

1000

0 0

pod

yie

ld (

g m

-

2)pod

yie

ld (

g m

-

2)

22-O

ct

8-Nov

22-N

ov

8-Dec

22-D

ec

22-Ja

n

8-Ja

n

22-O

ct

8-Nov

22-N

ov

8-Dec

22-D

ec

22-Ja

n

8-Ja

n

10

20

30

40

50

avera

ge t

em

pera

ture

(°

C)

tota

l rain

fall

(mm

)

20

40

60

80

100

non-infested

100 O. crenata seeds kg-1 soil

Model applications - 3

Multi-Season Simulations

year

1980 1985 1990 1995 2000

faba

bea

n po

d yi

eld

(g m

-2)

0

200

400

600

800

1000 broomrape seed bank (seeds m

-2)

0

1x106

2x106

3x106

4x106

year

1980 1985 1990 1995 2000

faba

bea

n po

d yi

eld

(g m

-2)

0

200

400

600

800

1000 broomrape seed bank (seeds m

-2)

0

1x106

2x106

3x106

4x106

200

400

600

800

1000

0

Tel Hadya

Adana

yield of non-infested cropyield of infested crop

seed bank (0-15 cm)

0

pod

yie

ld (

g m

-

2) pod

yie

ld (

g m

-

2)

200

400

600

800

1000

0

1

2

3

4

0

1

2

3

4

seed

ban

k (m

illion

seed

s

m-2)

seed

ban

k (m

illion

seed

s

m-2)

•5-course rotation unfeasible at both locations

•more rainfall more biomass more parasite seeds

•high soil moisture level rapid seed decay

1980

1985

1990

1995

2000

1980

1985

1990

1995

2000

Model applications - 4

• Evaluation of trap cropping, soil solarisation,

biological control and further measures

• Data collection for more mechanistic modeling of

seed bank decay

• Addition of a spatial component (cellular automaton)

• Application of the approach to further host-parasite

associations

• ... Your suggestions ?

Prospects for model improvement

• On the APSIM approach and framework:- McCown, Hammer, Hargreaves, Holzworth, Freebairn (1996). Agric.

Syst. 50, 255-271.

- Keating, Carberry, Hammer et al. (2003). Eur. J. Agron. 18, 267-288.

- Wang, Robertson, Hammer et al. (2003). Eur. J. Agron. 18, 121-140.

• On Host-Parasite Simulation:- Manschadi, Sauerborn, Stützel (2001). Weed Res. 41, 311-324.

- Manschadi, Wang, Robertson, Meinke, Sauerborn (2003).

www.regional.org.au/au/asa/2003/c/18/manschadi.htm

- Manschadi, Hargreaves, Grenz, DeVoil, Meinke (2004).

www.regional.org.au/cs/2004/poster/ 2/8/1218_manschadi.htm

- Grenz, Manschadi, DeVoil, Meinke, Sauerborn (2004).

www.regional.org.au/cs/2004/poster/2/4/1/1236_grenz.htm

Selected references