Resistance Management and Sustainable Use of Agricultural Biotechnology

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Resistance Management and Sustainable Use of
Agricultural Biotechnology
George Frisvold Department of Agricultural
Resource Economics University of Arizona
4th Annual Berkeley Bioeconomy Conference in
conjunction with the NC-1034 Research Conference
University of California, Berkeley March 24-6,
2011
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Problem Statement

• Transgenic crop varieties with insect resistant
  (IR) and herbicide resistant (HR) traits can
  provide significant economic and environmental
  benefits
• Benefits will be short-lived if resistance not
  delayed

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Problem Statement

• Despite 3 documented cases of field-evolved
  resistance, there have been no economically
  significant field control problems for IR Bt
  crops
• Glyphosate-resistant weeds have become an
  economically significant problem in the SE US
• What accounts for the difference?

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Whats at Stake?

• Loss of economic benefits
• Loss of environmental benefits
• Negative demonstration effect for biotechnology

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Adoption of genetically modified (GM) crop
varieties (as a share of world hectares and as a
share of hectares in approving countries)
Cotton Maize Canola Soybeans
Total World Hectares Planted to GM Varieties () 49 23 27 66
Hectares Planted to GM Varieties in Countries Where GM Varieties of Crop Have Been Approved () 78 60 72 90
Crop Hectares in Countries where GM Varieties of Crop Have Been Approved ( of total) 63 39 37 74
Crop Hectares in Countries where GM Varieties of Crop Have Not Been Approved ( of total) 37 61 63 26
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Difference in Resistance

• Depends on attributes of Bt and HR crop
  technologies
• Consistency with IPM principles
• Diversification vs. concentration in pest control
• And on regulatory and institutional setting
• This also depends on attributes of technology

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Properties of IR and HR Crops
IR Crops HR crops
Spectrum Narrow Broad
Target pest mobility High Lower
Externalities Bt microbial sprays / organic agriculture Initially none / Potential loss of conservation tillage
Management intensity High Low
Compatibility with IPM or IWM High Low thus far
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Properties of IR and HR Crops
IR Crops HR crops
Availability of substitutes No close substitutes for Bt Price signals suggest no scarcity
Resistance management Federally regulated Decentralized, voluntary
Scientific understanding of RM strategies Relatively high Lower
Costs of RM Low for many growers Prevention costs similar to ex post mitigation costs
Ability to monitor RM Higher Low
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Organization of Resistance Management

• Miranowski Carlson, National Academy book
  chapter (1986)
• Predicts organizational form of RM
• Useful starting point
• One would expect voluntary, monopolist led RM for
  HR crops
• Expect more regulatory approach for IR crops

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3 Documented cases of field-evolved resistance to
Bt crops

• Spodoptera frugiperda (fall armyworm) to Cry1F
  toxin in Bt corn in Puerto Rico
• Busseola fusca (maize stalk borer) to Cry1Ab in
  Bt corn in South Africa
• Helicoverpa zea (cotton bollworm) to Cry1Ac and
  Cry2Ab in Bt cotton in the U.S. Southeast
• Possible 4th case (pink bollworm) in India

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Bt crop resistance susceptibility

• 5 studies from China and India with ambiguous
  evidence of resistance of Helicoverpa armigera to
  Cry1Ac in Bt cotton.
• No increase in resistance for 7 pests
• H. zea and H. armigera still susceptible across
  many areas

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Resistance has not led to field level control
failures

• Chemical control of target pests still effective
  
• Introduction of crops with multiple Bt toxins
• But . . . 2010 saw increase in bollworm / budworm
  spraying and damages in MS Delta

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Acres treated trending up in LA MS
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Applications up in all 3 states
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Greater losses per acre in 2010
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Weed species with glyphosate resistant
populations states with glyphosate-resistant weed
populations
Populations, blue States, red
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Costs of HR weeds

• Weed management cost estimates in US range from
  30-160 per hectare
• Severe cases have led to crop abandonment
• Regarding Palmer amaranth
  there are no economical programs to manage this
  pest in cotton (Culpepper and Kichler, 2009)
  

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Rise in Glyphosate, Loss of Diversity of Mode of
Action
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Corn Reliant on Glyphosate and Triazine Herbicides
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Price Indices for Agricultural Inputs in the US
Herbicides Herbicides Herbicides Insecticides Insecticides Fertilizer Fertilizer Fuels Fuels Labor Labor Tractors Production Items
1997 100 100 100 100 100 100 100 100 100 100 100 100 100
1999 97 97 108 108 87 87 89 89 110 110 106 106 93
2001 96 96 111 111 102 102 114 114 119 119 110 110 101
2003 96 96 112 112 102 102 132 132 128 128 113 113 104
2005 99 99 111 111 136 136 204 204 134 134 123 123 118
2007 104 104 114 114 179 179 249 249 144 144 133 133 134
2009 121 121 124 124 227 227 215 215 152 152 148 148 153
2010 115 115 126 126 203 203 267 267 151 151 154 154 157

Percent Change Percent Change Percent Change
1997-07 1997-07 4 14 14 79 79 149 149 44 44 33 33 34
2007-10 2007-10 10 11 11 14 14 7 7 7 7 14 14 17
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Herbicide Prices Have Fallen Relative to Other
Inputs
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Special Issue Herbicide Resistant Crops
Diffusion, Benefits, Pricing, and Resistance
Management
Volume 12 // Number 3 4 // 2009
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Percent of growers often or always adopting
resistance management practice
US Cotton
Source Frisvold, Hurley, and Mitchell, 2009
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Percent of growers often or always adopting
resistance management practice
Corn
Cotton
Soybeans
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Plant Breeders to the Rescue?

• Pyramiding multiple Bt toxins in single crop
  varieties
• Stacking traits Crops that are resistant to
  multiple herbicides
• Allows rotating herbicides with different modes
  of action
• Homogeneous blends mixtures with different
  modes of action
• Quick registration of blends anticipated

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Top-Down vs. Bottom Up Approaches to RM

• Top-Down
• Less management intensive
• Relies on a small number of traits (are these
  enough given resistance to individual traits?)
• Growers passively selecting products off the
  shelf
• Relies on technology to keep one step ahead of
  resistance
• Treadmill continues in different form?

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Top-Down vs. Bottom Up Approaches to RM

• Bottom Up
• Active grower involvement in cooperative RM
• Education to combat common pool externalities
• Two way flow of information between growers and
  scientists / regulators

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Lessons from Arizona

• Bt cotton introduced into mature area-wide IPM
  program
• Heavy reliance on scientific information
• Insecticide use on target pest (PBW) and for all
  pests has declined
• No increase in resistance
• PBW Eradication under way with Bt cotton as a
  centerpiece

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Total AZ Cotton Insecticide Applications Trending
Down
Source Frisvold, 2009
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Trend Continues
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Summing Up

• Failure to develop successful RM strategies will
  deprive current adopters of the benefit of crop
  biotechnology have a negative demonstration
  effect
• Key factors determining RM success are technology
  attributes and institutional capacity
• Public and private plant breeding can play a
  critical role in developing stacked traits that
  reduce over-reliance on single chemical compounds
• IR and HR crops will be more sustainably deployed
  if embedded in IPM / IWM programs with strong,
  outward extension linkages to farmers and
  backward linkages to research institutions
• Role of Extension
• Information provision
• Can facilitate farmer collective action for
  area-wide RM
• Provide government agencies with information
  needed to increase the flexibility and
  cost-effectiveness of resistance management
  regulations