Pardey et al -turkey bgri stripe rust (4-28-2014)
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The Global Occurrence and Economic Consequences of Stripe Rust in Wheat Philip Pardey, Yuan Chai, Jason Beddow, Terry Hurley, Darren Kriticos and Hans Joachim-Braun University of Minnesota, CSIRO, and CIMMYT Second International Wheat Stripe Rust Symposium Regional Cereal Rust Research Center, Izmir, Turkey April 28, 2014
Transcript of Pardey et al -turkey bgri stripe rust (4-28-2014)
The Global Occurrence and Economic Consequences of Stripe Rust in Wheat
Philip Pardey, Yuan Chai, Jason Beddow,
Terry Hurley, Darren Kriticos and Hans Joachim-Braun
University of Minnesota, CSIRO, and CIMMYT
Second International Wheat Stripe Rust Symposium
Regional Cereal Rust Research Center, Izmir, Turkey
April 28, 2014
Stripe Rust: Bio-economic cum Policy Questions
What is the global extent of this disease?
• Where is it likely to occur and persist?
What share of global wheat area and production is susceptible to the disease?
What is the likely global losses in wheat production associated with this disease?
What are the global research investment implications of this disease?
Losses Attributed to Wheat Rust
Will Stem Rust Destroy the World’s Wheat Crop?
“…it is unlikely that stem rust race Ug99 or its descendants will destroy the world’s wheat crop”
Singh et al. (2008, p.305)
“This *stem rust+ is a time bomb…Ug99 is going to lie there, and then all of the sudden its going to go boom.”
Quote attributed to Borlaug (Science 2009, p. 721.)
Implied losses in 2009/10 attributed to wheat stem rust: 43.2 to 302.4 MMT
Fisher et al. (Nature 2012, Table s1)
“*Stripe rust+ losses can be severe (50%) due to shriveled grain and damaged tillers. In extreme situations, stripe rust can cause 100% losses.”
Roelfs et al. (CIMMYT 2002, p.2)
Stem Rust – Global Assessment Summary
Climate suitabilityof stem rust
Suitable
Persists
Reported Occurrence
Source: Pardey et al. (2013) from USDA (various years)
Average 2.5% per year
Stem Rust – Global Assessment SummaryStochastic Structure of U.S. Losses Attributed to Stem Rust
Average 0.29% per year
Stem Rust – Global Assessment Summary
Climate suitabilityof stem rust
Suitable
Persists
A sustained investment of $51.1 million per year (2010 prices) in stem rust research could be justified economically
Historical and Current Stripe Rust Threats
• Historically, stripe rust has mainly beenendemic only in cool climate regions
• In recent decades, stripe rust has spreadrapidly to areas previously unaffected
Before 2000 After 2000
0 Not recorded, or no response
1 Rare
2 Localized in some seasons
3 Localized in most seasons
4 Widespread in some seasons
5 Widespread in most seasons
N = 29
U.S. Wheat Yield Losses Attributed to Stripe Rust
U.S. Wheat Yield Losses Attributed to Stripe Rust
1960
2012
Global Stripe Rust Occurrence
Modeling Pests and Diseases- A Spatial Approach
CLIMEX Modeled Suitability for Stripe Rust (Beta)
Suitable
Persists
Observed and Modeled Occurrence of Stripe Rust
Observed and Modeled Occurrence of Stripe Rust
Observed and Modeled Occurrence of Stripe Rust
Observed and Modeled Occurrence of Stripe Rust
Observed and Modeled Occurrence of Stripe Rust
Area Production
Region Suitable Persists Suitable Persists
(percent)
North America 59.9 16.9 63.1 18.6
sub-Saharan Africa 82.6 81.2 83.0 82.0
LAC 85.0 83.0 89.7 88.5
Asia 59.1 32.9 69.4 39.2
FSU 66.2 9.7 78.9 15.7
Australasia 53.3 45.9 55.6 48.0
World 72.0 42.0 79.4 51.2
Stochastic Structure of U.S. Losses Attributed to Stripe Rust
The changing structure of stripe rust epidemics
1961-1984: significant yield losses
1985-1999: use of resistant cultivars and fungicide
Since 2000: new stripe rust pathotypes
0
0.5
1
1.5
2
2.5
3
3.5
4
4.51
96
1
19
64
19
67
19
70
19
73
19
76
19
79
19
82
19
85
19
88
19
91
19
94
19
97
20
00
20
03
20
06
20
09
20
12
Pe
rce
nt
Loss Average 0.54% per year
Average 0.15% per year
Average 1.5% per year
Global Stripe Rust Losses Estimates
Reference
Period
Counterfactual
Loss
Average annual losses
(million metric tons)
Value of the annual losses
(million U.S. $ per year)*
1961-84 none 1.04 $186
1985-99 none 0.53 $95
2000-12 none 5.77 $1,032
Reference
Period
Counterfactual
Period
Losses Averted
(million metric tons)
Value of the benefits
(million U.S. $ per year)*
1961-84 1985-99 0.74 $132
1985-99 1985-99 0 0
2000-12 1985-99 5.15 $922
* 2010 average US wheat prices
No Loss Counterfactual
Low Loss (1985-1999) Counterfactual
Approach
Estimate of annual investments to avert projected losses (costs) attributable to
stripe rust through to 2048
Ninety five percent chance of realizing a modified internal rate of return of at
least 10 percent per year
Economically Justified R&D Spending (2010 prices)
$36.8 million per year, or 17.1 cents per hectare (with a no loss counterfactual)
$32.9 million per year, or 15.3 cents per hectare (with a low loss counterfactual)
Comparative (Stem rust) Information
• Economically justified investment in stem rust was $51.1 million per year
• U.S. wheat farmers spent $15.75 per hectare on seed
Economically Justifiable R&D Investment
Summing Up
Earlier assessment suggests that around $50 million per year on average be invested in research to avert prospective global losses from stem rust, double what is being spent of late
Evidence suggests a change in the spatial pattern and magnitude of wheat yield losses attributable to stripe rust
• Around 72 percent of the world’s wheat area is susceptible to this disease
Beta assessment suggests that around $35 million per year (about two-thirds the corresponding stem rust research investment) be spent to alleviate global losses from stripe rust, substantially more than would have been justified several decades ago
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