With the benefit of hindsight: a bioeconomic analysis … 11...biosecurity built on science With the...

Science Exchange 2015 | Conference Handbook 89

With the benefit of hindsight: a bioeconomic analysis of past pest incursions (1033)Dr m. Chalak1,2, Assoc Prof B. White1,2 and Miss C. Day1,2 1Plant Biosecurity Cooperative Research Centre, 2University of Western Australia

The potato cyst nematode (PCN) (Globodera rostochiensis) is a serious pest of potatoes that causes significant crop damage in Australia and worldwide. PCN was discovered in Wandin Victoria in 1991 and then spread slowly to other regions in the state up to the present day. The aim of this study is to analyse the costs and benefits of past policy and management decisions in response to the incursion of PCN in Victoria. To do this we first estimate the probability of spread for different control strategies using information about the location and the date of spread of PCN in Victoria as well as the location of PCN-free potato farms. We use Monte Carlo simulation to compare the Net

Present Value for the cost of different decisions. Our analysis shows that the lowest economic costs are achieved if PCN is eradicated from the state and PCN infested farms were converted to other enterprises. This decision minimises the soil movement and spread of PCN. However, the decision by the Victorian Government was to contain PCN within infestation zones and allow potato production to continue at PCN infested farms. Containment has relatively higher economic costs because it results in a higher spread rate for PCN and has larger containment and transaction costs due to requirements for surveillance and movement licences.

Presenting authors biography

Morteza Chalak is a Research Assistant Professor at the University of Western Australia, School of Agricultural and Resource Economics. His research interests include bioeconomic analysis of biosecurity issues, economic modelling and optimisation for the control of pest and disease in Australia. He has been working at the University of Western Australia since 2009. In 2009 he graduated from his PhD from Wageningen University, the Netherlands. The title of his PhD

thesis was Economics of controlling invasive species.

Dr Morteza Chalak 08 6488 5508 [email protected]

Assoc Prof Ben White Project leader 08 6488 3409 [email protected]

More information

www.pbcrc.com.au/research/project/1033

biosecurity built on science

With the benefit of hindsight: a bioeconomic analysis of past pest

incursions

Morteza ChalakResearch Assistant Professor

Plant Biosecurity Cooperative Research Centre


Problem being addressed

Potato Cyst Nematode (PCN) (Globodera rostochiensis) is a serious pest of potatoes that has caused significant crop damage in Australia and worldwide



Low levels of infestation are difficult to detect PCN can survive in soil in the absence of a host plant for 20-30

years



PCN can be dispersed through movement of soil by human The maximum loss of potato production has ranged from 60%

to 97%



PCN was found in Victoria in 1991



Potato industry in Victoria Fresh potato: 99,584 tons Potato processing: 137,135 tons Seed production: 39,919 tons



Policies optionsPolicy 1: Current (containment while allowing potato production on infested farms)

Policy 2: Containment and not allowing potato production on infested farms

Policy 3: Early eradication attempt

Policy 4: No control and not allowing potato production on infested farms

Policy 5: No control and allowing potato production on PCN infested farms



Institutional costs

Fumigation costs

Market restrictions

Surveillances Yield loss

Containment costs

Early Eradication

No control



Question: is the current policy cost-effective compared to alternative policies?

Containment

PCN


Spread of PCN

PCN was discovered in Victoria in 1991 in Wandin and then spread slowly to other regions in the state up to the present day.


Spread of PCN

We estimate the location of potato farms using Australian Bureau of Statistics (2011), Basemaps aerial photos, soil and slope maps.


Spread of PCNProbability of spread

PS: probability that an uninfested potato farm is infested by an infested farm

d: the distance of the uninfested potato farm from the infested farm

a: spread coefficient

+

=i

ii da

dPC 1

+=

dad

PS 1


Spread of PCN

a (spread coefficient)Mean

2.376

Average for 1.046 and 2.376

1.7065

Minimum value for 95% confidence interval

1.046

Maximum value for 95% confidence interval

5.556


6.24

Mean

2.376


1.7065


1.046


5.556


6.24


Spread of PCN

a (spread coefficient assumptions)Mean

Policy: Current (containment while allowing potato production)

2.376


Policy: Containment and not allowing potato production on infested farms

1.7065


Policy: Early eradication attempt

1.046


Policy: No control and not allowing potato production on infested farms

5.556


Policy: No control and allowing potato production on infested farms

6.24


Spread of PCN

0

10

20

30

40

50

60

0 10 20 30

num

ber

of in

fest

ed f

arm

s

Years

6.24

5.556

2.376

1.7065

1.046

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 10 20 30

New

infe

stat

ions

Years

6.24

5.556

2.376

1.7065

1.046


Model We use the earliest infestation (Wandin in 1991) as the

initial condition and simulated the spread of PCN for different policy scenarios for 24 years (T, 1991 to 2015).

Monte Carlo simulation using 1000 random draws from a binomial distribution.

+

=i

ii da

dPC 1


Results Policy cost

Policy 1: Current (containment while allowing potato production)

Benefit loss per farm= $137,000, a=2.376, NPV loss for all farms=$2.9m

Containment cost=$4.7m. SD: 1,075,373.

$7.6m

Policy 2: Containment and no potato production on infested farm


Containment cost=$4.7m. SD: 1,260,438.

$8.6m

Policy 3: Early eradication attempt


Eradication cost=$0.8m. SD: 882,583.

$4.5m

Policy 4: No control and no potato production on infested farms


Control cost=0. SD: 5,737,055.

$5.7m

Policy 5: No control and allowing potato production on PCN infested farms


Control cost=0. SD: 5,880,363.

$4.6m


Results

0

200

400

600

800

1000

7.2

8.1

8.7

9.9

10.8

11.1

12.3

15.4

Mor

e13

.215

.1

Num

ber o

f sim

ulat

ions

Present value of economic costs ($million

0

200

400

600

800

1000

4.3

6.6

7.3

6.4

7.5

5.9

8.2

8.9

10.8

10.1

11.0

Num

ber o

f sim

ulat

ions

Present value of economic costs ($million)

0

200

400

600

2.4

7.4

15.7

17.3

22.3

30.7

37.3

35.6

50.6

44.0

49.0

Num

ber o

f sim

ulat

ions

Present value of economic costs ($million)

Containment

No control

Early eradication attempt


Who will directly benefit from the research?

Government organisations including Departments of Environment and Primary Industries

Potato growers


Challenges and issues arising from the research

General challenges dealing with new incursions: Availability of recorded data to estimate spread model. Short time frames for quick policy responses.


Impact delivery plan

State departments of agricultureare advised to consider a rapid eradication response if PCN is detected in new regions.


The End-User Advocates perspective

The director of Plant Biosecurity for the Department of Agriculture and Food, John van Schagen. General support with the project Interest in the results found Applicability of the results with the new incursion of similar

pests


Thank you

For more information, please email [email protected]

Thanks to Ben White (UWA), Michael Renton (UWA), Cheryl Day (UWA), Maggie Triska (UWA), Sarah Collins (DAFWA), Jacque Edwards (DEDJTR, Victoria), John Van Shagen (DAFWA), Jacquie Edwards (DEPI Victoria), Mike Hodda (CSIRO), David Cook (DAFWA).

mailto:[email protected]

With the benefit of hindsight: a bioeconomic analysis of past pest incursionsProblem being addressedProblem being addressedProblem being addressedProblem being addressedProblem being addressedProblem being addressedProblem being addressedProblem being addressedSpread of PCNSpread of PCNSpread of PCNSpread of PCNSpread of PCNSpread of PCNModelResultsResultsWho will directly benefit from the research?Challenges and issues arising from the researchImpact delivery planThe End-User Advocates perspectiveThank you

With the benefit of hindsight: a bioeconomic analysis … 11...biosecurity built on science With the...

Documents

Transcript of With the benefit of hindsight: a bioeconomic analysis … 11...biosecurity built on science With the...