predicting the benefits of banana bunchy top virus eradication in australia
DESCRIPTION
Benefit cost analysis is a tried and tested analytical framework that can clearly communicate the likelihood of net benefits or costs resulting from investment decisions to diverse stakeholder audiences. However, in a plant biosecurity context, it is often difficult to predict policy benefits over time due to complex biophysical interactions between invasive species and their hosts.TRANSCRIPT
biosecurity built on science
Predicting the Benefits of Banana Bunchy Top Virus Exclusion from
Commercial Plantations in Australia
Cooperative Research Centre for National Plant Biosecurity
David Cook Department of Agriculture and Food
Western Australia
biosecurity built on science
biosecurity built on science
biosecurity built on science
Outline
Banana Bunchy Top Virus (BBTV) □The issue □Impact and management of the virus
Estimating the benefits of an exclusion policy □Model in brief □Results
Conclusions
biosecurity built on science
The Issue Regional economic significance
□Australia contributes less than 0.5% of global production; □In 2010, Qld., NSW, NT and WA produced 301,450T of
bananas with a gross value of $492.2 million.
BBTV is one of the most economically significant diseases of bananas □Present in eastern Australia since the early 1900s; □In 1993, a five-year Banana Plant Health Improvement
Project was initiated by the industry aimed at eradicating BBTV from Australia;
□Substantial reductions in BBTV prevalence in commercial plantations was achieved, but not eradication due to externalities and incentive misalignment;
□Currently an exclusion management approach is being considered.
biosecurity built on science
BBTV Management Established throughout Southeast Asia, the Philippines,
Taiwan, most of the south Pacific Islands, and parts of India, Africa and Australia (NSW and Qld.);
The destructive effects of the virus were demonstrated in NSW in the 1920s when approximately 90% of the area under banana cropping was forced out of production.
The banana aphid (Pentalonia nigronervosa), established in most banana growing regions throughout the world, transmits BBTV;
Control within plantations involves insecticide treatments (2 × dimethoate applications, approx. $150/ha);
Since there are no known treatments against BBTV once infection has occurred, exclusion from commercial plantations involves destruction of affected plants and creation of a buffer zone (i.e. “cookie cutter” approach, approx. $15,000/ha);
biosecurity built on science
Conceptual Model
p
q
h(q)
g(q)
f(q)
q0 q1
p0
p1
BBBTV = ΔPS - c(s,a)
biosecurity built on science
New satellite
population
estP
Impact Simulation Model
rteNK
KN−
−
+
=11
min
APsat µ=
Established population
24 rtDA π=
Parameters: Pent - Entry probability
Pest - Establishment probability A - Area infected D - Diffusion coefficient r - Intrinsic rate of population & density increase N - Local population density Nmin - Initial population density K - Carrying capacity Psat - Satellite probability µ - Rate of new satellite generation t - Time period
entP
Parameters:
Detection probability = Binomial(1.0, 0.6)
Probability of eradication given an infected area, A = e-0.15×A
biosecurity built on science
Active Containment
Nil Management
0
2,000
4,000
6,000
8,000
10,000
12,000
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
Area
Affe
cted
by
BB
TV (H
a)
Year
95%
75%
Mean
25%
5%
BBTV Spread
biosecurity built on science
Benefits of Exclusion
biosecurity built on science
Conclusions
Biosecurity risk management decisions are highly uncertain □ Any model is a simplification of reality.
There appear to be substantial production benefits from adopting an active containment policy for BBTV □ $16-27 million per year.
The other component of CUBA – the spatial incursion management tool □ Recently showcased in a war games workshop in Melbourne
using the example fire blight; □ A model demonstration will be held at morning tea and lunch
time.
Thank you to all CUBA project team members, past and present! □ Jean-Philippe Aurambout, Art Diggle, Jacqueline Edwards,
Michael Hurley, Darren Kriticos, Shuang Liu, Kim Lowell, Abu-Baker Siddique and Oscar Villalta.
biosecurity built on science
Thank You
Dr David Cook
Senior Economist South West Agricultural Region Department of Agriculture and Food Western Australia PO Box 1231 BUNBURY WA 6231
T: +61 8 9780 6179 M: +61 477 302245 E: [email protected]
W: www.agric.wa.gov.au/
LONG LIVE CUBA!!