Post on 11-Aug-2020
transcript
Managing Herbicide Resistance
Franck E. Dayan
Bioagricultural Sciences and Pest Management
Colorado State University
• Evolution of herbicide resistance
• Different types of mechanisms of resistance
• Resistance to glyphosate, PPO inhibitors, ALS inhibitors and PGR
• Multiple herbicide resistance
• Managing herbicide resistance
Outline
Darwin focused on the change resulting from a Competitive Struggle for Existence
Mr. Herbert Spencer was influenced by Darwin’s The Origin of Species and coined the term ‘Survival of the Fittest’
Darwin later adopted the term to mean ‘better designed for an immediate, local environment’
Evolution
Individuals able to survive a herbicide dose that normally provides effective control of that species
Evolution of herbicide resistance
"better designed for an immediate, local environment“
Délye et al. 2013 DNA Analysis of herbarium specimens of the grass weed Alopecurus myosuroides reveals herbicide resistance pre-dated herbicides. PLoS ONE 8(10): e75117. doi:10.1371/journal.pone.0075117
Old herbarium collections
Between 1788 and 1975 • Before any ACCase (Group 1) herbicides
Mutation for resistance to both FOPs and DIMs found in a sample from 1888
Blackgrass from France
Resistance exists before any herbicides are used
Left to Right: • Rice • Barnyard grass Mimics rice • Barnyard grass Normal • Genetic trait
Resistance will evolve to any persistent selection pressure
Avoids hand weeding
Emergence to Flowering (days)
20 40 60 80
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Fo
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% o
f p
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0
20
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60
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Slide by M. Walsh Harrington Seed
Destructor
Resistance will evolve to any persistent selection pressure
Intercepts and destroys weed seeds during grain crop harvest. The interception and destruction of weed seeds occurs during grain crop harvest on the chaff fraction exiting the grain harvester
Adaptive capacity of wild radish to halve its time to flowering following five generations
Avoids seed destruction
Chronological increase in unique (species and
MOA) cases of evolved herbicide-resistant weeds worldwide
History of herbicide resistance
1st reports of ALS & ACCase resistance
- mid 80’s
RR™ introduced US in 1996
Roundup resistance
1st report of triazine resistance - 1968
Duke, S. O.; Dayan, F. E., Herbicides. In eLS, John Wiley & Sons, Ltd: Chichester, UK, 2018; p 11
Herbicide Resistance by MOA
History of herbicide resistance
Busi et al 2018 Weed resistance to synthetic auxin herbicides. Pest Manag. Sci. 2018, 74, 2265-2276
ALS inhibitors (1979)
Accase inhibitors (1974)
Glyphosate (1974)
Synthetic auxins (1945)
History of herbicide resistance
History of herbicide resistance
History of herbicide resistance
Weed biology
1. Outcrosser/self-infertility
2. High level of genetic diversity
3. High seed production
4. Some seed dormancy
5. Highly competitive
Characteristics associated with resistance
1. MOA involves a primary gene product 2. Nuclear-encoded, semi-dominant or
dominant gene 3. Herbicide is a non-competitive
inhibitor 4. No fitness penalty for resistance 5. Herbicide is extremely effective 6. Has some persistence in the soil
Characteristics associated with resistance
Herbicide chemistry
1. Frequent use of herbicides with a similar mechanism of action – this is the most important of all factors
2. Monocultures and crop rotations that rely on the same herbicide mechanism of action for weed control
3. Lack of non-chemical weed control practices such as cultivation, stubble burning, stale seedbeds and competitive and cover crops
Characteristics associated with resistance
Resistance linked to farming practices
Any trait which slows/prevents herbicide reaching the site of action, or reduces toxic effect at site of action
Target Site
Mutation Increased expression/ Gene amplification
Potential Herbicide Resistance Mechanisms
Non-Target Site
Metabolism Altered translocation & sequestration
Reduced foliar uptake
General oxidative stress response
Resistance mechanisms
Resistance to glyphosate
Glyphosate-resistant species Year Populations Situation
Annual ryegrass (Lolium rigidum) 1996 678# everywhere gly is used
Awnless Barnyard grass (Echinochloa colona) 2007 102 herbicide fallow
Liverseed grass (Urochloa panicoides) 2008 4 herbicide fallow
Flaxleaf fleabane (Conyza bonariensis) 2010 65 roadsides
Windmill grass (Chloris truncata) 2010 11 herbicide fallow; roadsides
Wild radish (Raphanus raphanistrum) 2010 3 herbicide fallow
Great brome (Bromus diandrus) 2011 5 fence lines
Tall fleabane (Conyza sumatrensis) 2012 8 roadsides
Sowthistle (Sonchus oleraceus) 2014 5 herbicide fallow
Red brome (Bromus rubens) 2014 1 herbicide fallow
Sweet summer grass (Moorochloa eruciformis) 2014 1 herbicide fallow
Prickly lettuce (Lactuca serriola) 2014 1 herbicide fallow
Feathertop Rhodes grass (Chloris virgata) 2015 4 herbicide fallow; roadsides
Tridax daisy (Tridax procumbens) 2016 1 (Ord Irrig) herbicide fallow; channels
Winter grass (Poa annua) 2017 3* golf courses
Wild / willow-leaved lettuce (Lactuca saligna) 2017 2 vegetables
Northern barley grass (Hordeum glaucum) 2018 1 fences, buildings
# stopped counting; * Multiple Resistance 2,3,5,9,25
Increase in GR in 7 years
Country Number of species Country Number of species
2011 2018 2011 2018
USA 11 17 Australia 5 17
Canada 1 6 Czech
Republic
1 1
Brazil 5 8 Israel 2 2
Argentina 3 11 South
Africa
3 3
Chile 1 1 China 2 2
Spain 5 5 Malaysia 2 2
France 2 3 Italy 1 3
Resistance to glyphosate
Palmer amaranth 3x of glyphosate at 32 oz/ac
Glyphosate-resistant Palmer
1. High level of resistance
2. Trait that is nuclear encoded
3. Transferred through pollen flow
4. Potential for transfer to other amaranth species
5. Few alternative modes of action
Why is glyphosate resistant Palmer amaranth a big deal?
Glyphosate-resistant Palmer
Tranel, UI
10X copy number = Survived 4X label rate
3200 g a.e./ha
88 oz/ac
Glyphosate-resistant Kochia
M. VanGessel, UD
Resistant and susceptible horseweed following glyphosate application.
Glyphosate-resistant horseweed
Video by C Vanhorn Traps herbicide in dead leaves
Glyphosate-resistant giant ragweed
Species Country Mechanism First Year
Acalypha australis Asian Copperleaf
China 2011
Amaranthus quitensis Pigweed (quitensis)
Bolivia 2005
Amaranthus tuberculatus Common Waterhemp
United States Target and multiple SOA
2001
Ambrosia artemisiifolia Common Ragweed
United States Target and multiple SOA
2001
Descurainia sophia Flixweed
China 2011
Euphorbia heterohylla Wild Poinsettia
Brazil Multiple SOA 2004
Resistance to PPO inhibitors Group 14 herbicides
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illi
on p
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19
92
1
99
3
19
94
1
99
5
19
96
1
99
7
19
98
1
99
9
20
00
2
00
1
20
02
2
00
3
20
04
2
00
5
20
06
2
00
7
20
08
2
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9
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1
20
12
2
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3
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14
2
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20
16
Agricultural use
Roundup ready crop
Glyphosate resistance
0
420 g
4.2 g 0.42 g
42 g
Front row: Sensitive Back row: Resistant
Resistance to PPO inhibitors
Cobra (ai ha-1) dose response
M Normal PPX2
Gly
Resistant PPX2 has a codon deletion of glycine at position 210
With extra 90 bp at the 5’ end provide for dual targeting
M Dual targeted resistant PPX2 M
Origin of Resistance is in Mitochondria
PPO protein transport
acetolactate synthase
Acetolactate synthase (ALS) is involved in the biosynthesis of the branch-chain amino acids (valine, leucine, and isoleucine)
ALS is the target site of many herbicides that provide broad spectrum weed control at extremely low concentrations
Plants tend to evolve resistance to ALS inhibitors very rapidly
Symptoms include malformation, stunting, and reduced seed production
Effect of cloransulam-methyl on wild-type and resistance giant ragweed
pyruvate
valine isoleucine
2-ketobutyrate
leucine
2-aceto-2-hydroxybutyrate
2,3-dihydroxy-3-methylvalerate
NADPH
pyruvate
2-acetolactate
2,3-dihydroxy-3-isovalerate
NADPH
pyruvate
Resistance to ALS inhibitors
Area (×106 ha) treated with specific synthetic auxin herbicide active ingredients reported in 2014 (Dow AgroSciences proprietary sources, 2014).
Busi et al 2018 Weed resistance to synthetic auxin herbicides. Pest Manag. Sci. 2018, 74, 2265-2276
Resistance to PGR
– MOA does not result from interactions with a single gene product
– Multiple sites of action
– Resistance develops as a quantitative trait
– Multiple genes must be stacked together in order to develop resistance
– Very difficult to maintain resistance because of influx of susceptible pollen
– Multiple gene mutations could result in reduce fitness
RESISTANCE SLOW TO DEVELOP
Resistance to PGR
Multiple herbicide resistance
• Illinois waterhemp population has 4-way
resistance: Glyphosate, ALS, PPO, atrazine
• Kansas Kochia has glyphosate, ALS, atrazine,
Dicamba
• Other waterhemp populations resistant to HPPD
and 2,4-D
• No new modes of action in near future
• Have to sustain available herbicide resources
PSII Resistance
ALS Resistance PGR susceptible
Multiple resistance kochia
PRE • Scoparia – HPPD, 27 • Authority MTZ – PPO + PSII,
14 + 5 • Fierce – PPO + VLCFAE, 14 +
15 • Spartan – PPO, 14 • Clarity – auxin*, 4 • Atrazine – PSII, 5 • Linex – PSII, 7 • Corvus – ALS + HPPD, 2 + 27 • Zidua – VLCFAE, 15
Post • Clarity – auxin*, 4 • Starane – auxin, 4 (no R yet in CO • Sharpen – PPO, 14 • Impact – HPPD, 27 • Laudis – HPPD, 27 • Roundup* - EPSPS, 9 • Liberty – GS, 10 • Diflexx* – dicamba, 4 • Gramoxone – PSI, 22
Kochia can be resistant to Group 2; 5, 6, 7; 9; and 4
Kochia herbicides
MANAGEMENT OPTION LOW RISK MODERATE RISK HIGH RISK
Herbicide mix or rotation in cropping system
> 2 modes of action 2 modes of action 1 mode of action
Weed control in cropping system
Cultural*, mechanical and chemical
Cultural and chemical Chemical only
Use of same mode of action per season
Once More than once Many times
Cropping system Full rotation Limited rotation No rotation
Resistance status to mode of action
Unknown Limited Common
Weed infestation Low Moderate High
Control in last three years Good Declining Poor
Resistance risk assessment
https://hracglobal.com/
1- Has the same herbicide or herbicides with the same mechanism of action been used for several years? 2- Has the uncontrolled weed been successfully controlled by the same herbicide in previous years? 3- Are there live weeds beside dead weeds of the same species following a herbicide application? 4- Has a decline in control been noticed in recent years? 5- Are there resistant weeds in local fields, roadsides, farms, etc.? 6- Are other species in the same location being adequately controlled by your herbicide application?
Resistance risk assessment
With a number of ‘yes’ answers and other factors ruled out, resistance may be strongly suspected. At this point, leave a small area of weeds to collect whole plant or seed samples to test so resistance can be determined.
https://hracglobal.com/
Integrated Weed Management Chemical Applying herbicides to a crop
Mechanical Cultivation or ploughing to control emerged plants and bury non-germinated seed. It also includes harvest weed seed destruction such as stubble burning and cutting for hay or silage to prevent the weeds from setting seed.
Cultural Altering the crop planting date, row spacing and harvest timing to disrupt the weed cycle. It also includes planting crops that can out-compete weeds, buying certified seed that’s free of weeds and using a diverse crop rotation. Growers should also sanitize farm equipment when moving between fields.
https://hracglobal.com/
Biological Introduce insects and pathogens that control target weed species and introducing post-harvest grazing of growing weeds. Using a diversified crop rotation allows farmers to use these different weed techniques. Avoid successive crops that use herbicides with the same mechanism of action to control the same weed species in the same field.
Herbicide rotation and mixture
Use mixtures or sequential treatments of herbicides - Herbicide in the mixture should have different MOA, but target the same weed species - Consider all chemical control options before planting, in-crop and after harvest
Herbicide mixtures and herbicide rotations alone are not enough to prevent resistance. They must be used in a diversified plan than also incorporates mechanical, cultural and biological practices.
Avoid continued use of the same herbicides -That includes different herbicides with the same site of action, unless integrated with other weed control practices -Limit the number of applications of a single herbicide or herbicides with the same site of action in a single growing season
https://hracglobal.com/
1. High seeding rate
2. Narrow row spacing
3. E-W orientation
4. Competitive cultivar
Crop competition/agronomy
Barley
‘Stacking’ effective agronomic practices for sustainable weed management
Crop competition/agronomy
Northern Great Plains 10: Maintaining a database: invaluable reference
9: Strategic tillage: if, where, or when needed
8: Field & site-specific weed mgmt: 1 size may not fit all
7: Weed sanitation: border control and slowing HR dispersal
6: In-crop wheat-selective herbicide rotation: combating NTSR
5: Herbicide gp rotation: avoid back-to-back in-crop gp A or B
4: Herbicide mixtures/sequences: better than rotations
3: Pre- and post-herbicide scouting: know your enemy
2: Competitive crops & practices that promote competitiveness:
natural biological control
1: Crop diversity
Top 10 HRWM practices
Beckie and Harker 2017 Our top 10 herbicide-resistant weed management practices. Pest Manag. Sci.73, 1045-1052
Questions