understanding pesticide resistance fred fishel and j.a. ferrell, uf/ifas dept. of agronomy p.g....
TRANSCRIPT
Understanding Pesticide Understanding Pesticide ResistanceResistance
Fred Fishel and J.A. Ferrell, Fred Fishel and J.A. Ferrell, UF/IFAS Dept. of AgronomyUF/IFAS Dept. of Agronomy
P.G. Koehler and J.L. Castner, UF/IFAS Doc. SP121
When Pesticides Don’t Work
• Improper pest identification
• Incorrect pesticide dosage
• Improper application timing
• Pesticide doesn’t reach target pest
• Unfavorable environmental conditions
• State of poor pesticide conditions
• Pesticide resistance
F.A. Johnson, D.E. Short, and J.L. Castner, UF/IFAS Doc. SP93
When Pesticides Don’t WorkImproper pest identification
F.M. Fishel, UF/IFAS Pesticide Information Office
Crabgrass Bermudagrass
When Pesticides Don’t WorkImproper pest identification
F.A. Johnson, D.E. Short, and J.L. Castner, UF/IFAS Doc. SP93
When Pesticides Don’t WorkIncorrect pesticide dosage
F.M. Fishel, UF/IFAS Pesticide Information Office
When Pesticides Don’t WorkImproper application timing
CDMS
When Pesticides Don’t Work• Pesticide doesn’t reach target pest
F.A. Johnson, D.E. Short, and J.L. Castner, UF/IFAS Doc. SP91
When Pesticides Don’t Work• Unfavorable environmental conditions
CDMS
When Pesticides Don’t Work• State of poor pesticide conditions
F.M. Fishel, UF/IFAS Pesticide Information Office
Pesticide Resistance
F.M. Fishel, UF/IFAS Pesticide Information Office
Definitions: Resistance
An inheritable change in the sensitivity of a pest population that is reflected in the repeated failure of a product to achieve the expected level of control when used according to the label recommendation for that pest species.
F.M. Fishel, UF/IFAS Pesticide Information Office
Definitions: Tolerance
The inherent ability of a species to survive following a pesticide treatment.
F.M. Fishel, UF/IFAS Pesticide Information Office
Definitions: Cross vs. Multiple Resistance
Cross resistance: resistance to 2 or more pesticides that share the same mode of action.
Multiple resistance: resistance to 2 or more pesticides with different modes of action.
F.M. Fishel, UF/IFAS Pesticide Information Office
Resistance in General
• Kills susceptible pests, leaves resistant members of the population
• Resistant populations are usually resistant to all members of a chemical family
• Favored by continual use of a pesticide
D.E. Short and J.L. Castner, UF/IFAS Doc. SP 126
Resistance in General
C.R. Rainbolt et.al., UF/IFAS Doc. SS-AGR-243
“The Pesticide Treadmill”
1. Pest population rises2. Apply pesticides3. Pests become resistant4. Apply more pesticides5. Resistance becomes more prevalent6. Switch to new pesticide
Resistance Action Committees
• IRAC– http://www.irac-online.org/
• FRAC– http://www.frac.info/frac/index.htm
• HRAC– http://hracglobal.com/
Resistance: History
Insecticides
F.A. Johnson, D.E. Short, and J.L. Castner, UF/IFAS Doc. SP93
Insecticide Resistance is Costly
• Colorado potato beetle
• Budworm/bollworm complex
R.L. Jacques and T.R. Fasulo, UF/IFAS Doc. EENY146
J.L. Capinera, UF/IFAS Doc. EENY219
Causes of Insecticide Resistance
• Natural detoxification
• Binding site has become genetically modified
• Slower absorption by the insect
• Behavioral resistance
E.A. Buss, UF/IFAS Doc. EENY326
Causes of Insecticide Resistance
• Natural detoxification (metabolic resistance)
J.F. Butler, UF/IFAS Doc. EENY222
Causes of Insecticide Resistance
• Altered target-site resistance
Colorado Potato Beetle Larva Colorado Potato Beetle Adult
J.L. Jacques and T.R. Fasulo, UF/IFAS Doc. EENY146
Causes of Insecticide Resistance
• Penetration resistance
J.F. Butler, UF/IFAS Doc. EENY48
Causes of Insecticide Resistance
• Behavioral resistance
J.L. Castner, UF/IFAS Doc. EENY25
Practical Insecticide Resistance Management
• Consult a professional
• Select early-maturing varieties
• Select insecticides with care
S.E. Webb, UF/IFAS Doc. EENY802
Practical Insecticide Resistance Management
• Monitor the population
• Remove crop residues
S.E. Webb, UF/IFAS Doc. EENY802
Practical Insecticide Resistance Management
• Prevention
• IPM, IPM, IPM
S.E. Webb, UF/IFAS Doc. EENY802
Resistance: History
Fungicides
F.M. Fishel, UF/IFAS Pesticide Information Office
Fungicide Resistance
P.F. Harmon, UF/IFAS Doc. PP198
Fungicide Resistance Types
• Single gene
• Polygenic
• Cross- vs. multiple-resistance
P.F. Harmon, UF/IFAS Doc. PP203
Fungicide Resistance Factors
• Type of fungicide
• Frequency of use
• If used or alone or in combination
• Pathogen
• Viability of resistant biotypes
P.D. Roberts, UF/IFAS Doc. PP236
Fungicide Resistance Strategies
• Resistant varieties
• Crop rotation
• Dispose/destroy crop debris
• Soil sterilization
• Alternate fungicide groups
A.J. Gevens, UF/IFAS Doc. SP159
Resistance: History
Herbicides
F.M. Fishel, UF/IFAS Pesticide Information Office
Herbicide Resistance
• >300 resistant biotypes
• 183 species– 110 dicots– 73 monocots
• >270,000 field sites
F.M. Fishel, UF/IFAS Pesticide Information Office
I. Heap, International Survey of Herbicide Resistant Weeds
Herbicide Factors for Resistance
• Act on a single site of action
• Applied multiple times during a growing season
• Have long residual
• Used for several consecutive seasons
• Used as “stand-alones”
A.C. York, N.C. State University
Mechanism of Herbicide Resistance
• Exclusionary resistance– Differential uptake– Differential translocation– Compartmentalization– Metabolic detoxification
• Site of action resistance– Altered site
F.M. Fishel, UF/IFAS Pesticide Information Office
Weed Factors for Resistance
• Weed reproductive capability
• Weed seed dispersal mechanisms
F.M. Fishel, UF/IFAS Pesticide Information Office
Management Strategies
• Use herbicides only when necessary
• Rotate herbicides
• Use tank-mix or sequential mixtures
• Rotate crops
• Use caution if planting herbicide resistant crop varieties
F.M. Fishel, UF/IFAS Pesticide Information Office
Management Strategies
• Combine with mechanical control
• Where soil erosion is minimal, use primary tillage as a management component
• Scout fields regularly
• Clean equipment before moving
F.M. Fishel, UF/IFAS Pesticide Information Office
Glyphosate Technologies
• Glyphosate-resistant crops
• in-season glyphosate useBenefits Broad spectrum weed
control Crop safety Rotational crop flexibility Environmentally favorable
University of Wisconsin
Most Heavily Applied Pesticides - 1997• Atrazine (H): 75 – 82 million pounds• Metolachlor (H): 63 – 69• Metam sodium (F, H, I, N, Fm): 53 – 58• Methyl bromide (Fm): 38 – 45• Glyphosate (H): 34 – 38• Dichloropropene (N, Fm): 32 – 37• Acetochlor (H): 31 – 36• 2,4-D (H): 29 – 33• Pendimethalin (H): 24 – 28• Trifluralin (H): 21 - 25
Most Heavily Applied Pesticides - 1999• Atrazine (H): 74 – 80 million pounds• Glyphosate (H): 67 – 73• Metam sodium (F, H, I, N, Fm): 60 – 64• Acetochor (H): 3 – 35• Methyl bromide (Fm): 28 – 33• 2,4-D (H): 28 – 33• Malathion (I): 28 – 32• Metolachlor (H): 26 – 30• Trifluralin (H): 18 – 23• Pendimethalin (H): 17 - 22
Confirmed Glyphosate Resistant Weeds in the U.S. (2006)
Palmer AmaranthCommon WaterhempGiant RagweedHairy Fleabane
University of Wisconsin
Horseweed (Marestail)Common RagweedItalian RyegrassRigid Ryegrass
Glyphosate Resistant Weeds: U.S.
0
1
2
3
4
5
6
7
8
1996 1998 2000 2002 2004 2006
No
. of
sp
ec
ies
Rigid ryegrass
Horseweed
Italian ryegrass
Common ragweed
Waterhemp
Palmer amaranth
Giant ragweed
University of Wisconsin
Herbicide Costs Needed To Manage Palmer Amaranth in Georgia and North Carolina
Cotton
Soybean
Corn
Sensitive
Palmer
$18
$8
$10
Resistant
Palmer
$42
$24
$14
University of Georgia
"Stupidity is doing the same thing over and over again expecting different results"
~ A. Einstein
Resources
http://www.frac.info/frac/index.htm
http://www.irac-online.org/
http://hracglobal.com/
Photo/Diagram CreditsPhoto/Diagram Credits• University of Florida/IFAS• University of Georgia• N.C. State University• University of Tennessee• University of Wisconsin• CDMS
Fred Fishel, Ph.D.Department of AgronomyUniversity of Florida/IFASCopyright 2008 University of Florida
Mention of trade names in this presentation is solely for providing specific information. It is not a guarantee or warranty of the products named, and does not signify that they are approved to the exclusion of others of suitable composition. Use pesticides safely. Read and follow directions on the manufacturer’s label.