How resistant is Northern
Europe?
Fredericia
August 18, 2011
Hans G. Drobny
Resistance in Northern/Central Europe
•
•
•
•
What is resistance?
How is it organized?
Status of resistance
How to select and to establish
resistance?
• Some rules
• Outlook
What is Resistance?
The naturally occuring, inheritable ability
of individual biotypes within a pest
population, to survive pesticide
treatments which under normal
circumstances would control these
populations
This ability is genetically based (mutation),
will be selected by the respective
pesticide, and is passed onto the next
generation
Characteristics of metabolic and target-site resistance
Target-site
Metabolic
Target enzym mutation / binding
increased metabolic activity
Qualitative (practical): yes/no
Mode of action
Quantitative: decreasing efficacy
Resistant individuals practically
completely resistant
Varying degrees of resistance
Weeds: “nests” in field
Gradual shift of whole populations
Fitness good
Other MoA works
dominant heredity
chemical structure/ mechanism of
degradation
Fitness good
Other MoA molecules can be affected
the same time
Resistance: further definitions
• Cross resistance:
– A single mutation results in resistance against
several a.i.‘s, mostly from the same MoA group
• Multiple Resistance
– 2 or more mutations or mechanisms result in
resistance against same/different a.i.‘s or MoA
groups
• Target-Site Mutations
– Different locations of mutations on the enzym
can result in resistance (mostly „typical“
locations on each enzym)
– Subgroups of MoA groups can be affected in
different ways: FOP/DIM, SU/TAP/IMI, strob‘s
F129L
ALS Target Site Mutations
Resistance to sulfonylurea and triazolopyrimidine
Proline 197 to Ile, Ala, His - Raphanus
Resistance to imidazolinone
Alanine 122 to Thr - Xanthium
Ser 653 to Thr - Amaranthus spp.
Resistance to sulfonylureas
Proline 197 to Arg,Gln,Ser - Kochia, Papaver
Resistance to all ALS Inhibitors
Proline 197 to Leu - Amaranthus spp.
Alanine 205 to Val - Xanthium
Resistance to SU + IMI + TP
Trp 574 to Leu - Sisymbrium, Ambrosia
The ALS enzyme show its major mutations on the following
amino acids: ALA 122, PRO 197, ALA 205, TRP 574, SER 653
Metabolic Resistance ALOMY
schematic illustration of its development (UK, D)
% individuals/
population
metsulfuron
tribenuron
 thifensulfuron
amidosulfuron
FOP‘s

9 g/ha
mesosulfuron
.
.
flurpyrsulfuron
mesosulfuron 15 g/ha
propoxycarbazone
.
Ureas
.
P450 Potenz
0
6-8
8-12
today
years
HRAC guide line metabolic resistance
• In cases where metabolic resistance is
already present, the mode of action of the
herbicide is not always the key criterion.
In these cases, the mechanism of
degradation can be very important and
cross mode of action groups and
chemistries. No classification of herbicides
relating to degradation is available and
such examples need to be handled on a
case by case basis.
Who cares about resistance?
• Industry
– RAC‘s: Resistance Action Committee
– HRAC, IRAC, FRAC
• Registration authorities
– Notification and precautionary statements
– Action Groups („RAG‘s“): NORBARAG
• Official and private advisors
• Competition….
Resistance is „sexy“!
How is resistance organized?
• RAC‘s: Resistance Action Committees
–
–
–
–
–
Industry representatives, global scope
HRAC, FRAC, IRAC
Public / Internet
Specialized working groups
Classification of a.i.‘s into „mode of action“
groups, and cross resistance
– Guidelines for preventing/managing resistant
populations
– Development of test methods
– Establishment base lines
How is resistance organized -2?
• RAG‘s: Resistance Action Groups
–
–
–
–
–
–
Regulatory bodies, official advisors, industry
NORBARAG: Nordic and Baltic states
Germany: Fachausschuss PSM-Resistenz (3)
Austria: AGES „Runder Tisch Resistenz“
Monitoring resistant populations in territory
Guidelines for preventing/managing resistant
populations under local conditions
– Label statements
– Interface with the RAC‘s
NORBARAG Objectives
• to provide a forum for information exchange between people
actively involved in research into pesticide resistance and
efficacy evaluation of pesticides
• to ensure that cases of resistance in the Nordic-Baltic region is
verified and listed
• to discuss strategies to avoid resistance and to manage
resistant populations
• to define research needs, discuss test methodologies and
agree on standards
• to promote collaboration on resistance screening and other
research topics related to pesticide resistance
• to promote awareness on pesticide resistance issues e.g. by
producing educational material
• to maintain contacts to similar groups in other countries
Activities of German RAG‘s
– Reports/sharing of new findings/results
• Partly joint monitoring programs
– Connection to RAC‘s – local implementation
– Recommendations for practical management
under German/local conditions
• Crops and crop rotations
• Pests
• Available tools
– Fact finding for special approvals of products to
manage resistance issues
– External communication via Internet
Carbamate
OP-Ester
Pyrethroide
Häutungsbeschleuniger
Oxadiazine
Neonicotinoide
Diamide
Metamorphosehemmer
Example monitoring:
Blumeria graminis/proquinazid
Routine monitoring since 2006
Characterisation of less sensitive isolates with full dose response
Cross-resistance with metrafenone and cyflufenamid
 480 airborne isolates collected in 6 European countries
 Study carried out by EpiLogic
 Regular reporting/discussion of results at FRAC working group
“Azanaphthalenes”
 Presentation at German FRAG group
Example: Methodology development for monitoring M. aeneus
adults susceptibility to indoxacarb
Vial test
BTL
(a) pooter
(b) roller mixer
(c) glass tube
a
b
These are the proper glass vials
used for 2008 – 2009 bioassays
c
International survey resistant weeds
Characterization of Herbicide resistant Weeds
Example: Evaluation Methods at the whole
plant level
• Greenhouse test on pots :
Harvest Seeds or Plants
Planting seeds or
transplanting plants
From seeds 15 days are need
to reach stage 2-3leaves
Evaluation at
21 DAT
Plants at
3 leaves GS
Control
Resistant
Growth and
Evaluation
Susceptible
Treatment
Greenhouse set up
Example: Results molecular genetic analysis
Mutated Allel Position 197 in bold.
Mutation CCA zu ACA oder ACC : Prolin to Threonin.
Example: Resistance factor
Comparison dose-response curves of sensitive reference population
(MRS) and the suspect sample (SH 1)
Resistance factor calculated from ED50-values: RF = 59,6
Relevant Weed Resistance Issues
Northern Europe
• Triazin-resistant Weeds
– New: Chenopodium against Metamitron
• ALOMY
– Quantitative metabolic resistance against different a.i.‘s:
ureas, FOP‘s (not DIM‘s!), SU‘s, inh. of cell division
– ACCase target site resistance (FOP‘s/DEN and DIM‘s)
– ALS target site resistance
– multiple resistances: metabolic combined with ACCase- and
ALS-target-site resistance
• APESV
– Quantitative resistance against IPU and ALS-Inh.
– Target-site resistance against ALS-Inh. and ACCAse-Inh.(?)
• STEME, PAPRH, MATCH, MATIN, SONAR, CHYSE,…
– Target-site resistance against ALS-Inh.
– Nordic and UK; Germany: only MATSPX
Relevant Fungicide Resistance Cases
Germany and Northern Europe
• Strobilurines (QoI‘s)
– Target-site resistance Septoria tritici, Powdery Mildew
wheat, Erysiphe necator (grapes), Pyrenophora teres
(F129L)
– NORDIC: S.tritici, M.nivale, DTR, Ramularia, P.teres
• Triazoles
– „Shifting“ with several cereal diseases;
– NORDIC: Septoria tritici
• Phenylamides
– Downy mildew grapes and potatoes
• The „Resistance Trio“: Botrytis, Scab, Mildew
– Recent reports on metrafenone/cereals/Blumeria graminis
• Special laboratory used by most organisations:
Epilogic
Relevant Insecticide Resistance Cases
Germany and Northern Europe
• Pyrethroides
–
–
–
–
Meligethes
Other rape pests: Ceutorhynchus, Psylloides
Colorado Potatoe Beetle
Aphids
• Carbamates and OP-Esters
–
–
Several sucking and chewing insects
Only few actives remaining
• Neonicotinoides
–
–
–
–
First reports aphids (Phorodon humili) and White flies
increasing market shares/strong exposure (start seed dressing)
X-resistant to pymetrozyn (different chemistry, IRAC group 9)
Not X-resistant to flonicamid (similar chemistry, IRAC group 9)
• Some crops with only pyrethroids (widespread resistance) and
neonics: Rape, potatoes, beets
How come resistant populations?
• Naturally occurring mutations
– The more individuals there are, the higher is the probability of
mutated individuals/field
PLUS
• Selection of these mutants via a specific selection agent
– Pesticides are powerful and mostly specific selection agents
– Continuous application of the same selection agent leads to
propagation of the mutated individuals to a population
• Worst case example:
– Provide optimum conditions for growth and propagation of a weed
via cultural practices
PLUS
– Continuous application of the same MoA herbicides
– Blackgrass in the Northern German marsh areas
General Risk Faktors
• Changes in agronomic pratices: favour specific weeds
– Narrow crop rotations
– No-till systems
• Little (chemical) Renewal
– Cost rel. to market potential
• Glyphosate/Glufosinate tolerant crops
– High entry barriers (f.e. SU‘s)
• Regulatory authorities favour potentially „higher risk“ MoA
classes
– One-site Inhibitors (no/little side effects)
– Metabolically instable (fast degradation environment)
• Cancellations/limitations „robust“ (multi-site) a.i.‘s
– IPU, Trifluralin, …
• Revision 91/414/EEC into EU 1107/2009
– RAC‘s and RAG‘s do lobbying work to include/consider resistance
Task: establishment of a resistant
weed population
1.
Generate high population density of target weed
1.
- crop rotation: only winter or summer crops,
•
2.
- reduced/one-sided agricultural means:
•
3.
2.
No plough, very early seeding times
- allow/accept imperfect efficacy: many new seeds
One-sided application of herbicides
1.
2.
3.
4.
3.
Best for grasses: only wi-cereals
- 1 mode-of-action solo
- only post-em spring
- no change (MoA) in the whole crop rotation
- no mechanical or other field hygene
Protract seeds from affected fields to other fields
Task: establishment of a resistant
weed population– it works!
• Blackgrass (ALOMY) in England
–
–
–
Wi-cereals, mono culture, no plough for many years
IPU/CTU (m), FOP‘s (m), DIM+FOP (t-s), Lexus®/Attribut (m und t-s), „soil
herbicides“ (m?), Atlantis (m und t-s)
Marsh areas in Schleswig-Holstein follow closely…
• Several weed species Norway
–
–
–
–
Spring cereal mono culture
Almost exclusive use of ALS-inhibitors for many years: populations of several weed
species with ALS t-s resistance : MATIN, PAPRH, STEME, SPEAR…
Other MoA groups with higher taxes
Denmark: winter and spring cereals, mixtures different MoA common: much less
–
–
–
Winter cereals mono culture
Only product registered for several years: Ralon (fenoxaprop-e)
ACCase target-site (and metabolic) resistance
problems
• APESV in Sweden
• APESV in Poland und CZ
–
–
–
–
WWheat mono culture
25 years application ALS-Hemmers solo (Glean®) in autumn
Last 10 years specific ALS-inhibitors post-em spring: resistance against ALS-inh.
last 3-5 years application FOP‘s: resistance against fenoxaprop-e (and others?)
Resistance to ALS Inhibitor Herbicides
ALS Target Site Mutation:
Stellaria media case
Years
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
Crops
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Spring Barley
Herbicide Treatments
Chlorsulfuron + HBN
Chlorsulfuron + HBN
Metsulfuron-methyl + MCPP
Metsulfuron-methyl + MCPP
Metsulfuron-methyl + MCPP
Metsulfuron-methyl + MCPP
Metsulfuron-methyl + MCPP
Metsulfuron-methyl + MCPP
Metsulfuron-methyl + MCPP
Metsulfuron-methyl + MCPP
Metsulfuron-methyl
Metsulfuron-methyl
Confirmed resistance
Two important characteristics for the development of herbicide resistance were put
together in this field : crop monoculture and use of the same herbicide (9 years of
sulfonylurea treatments (chlorsulfuron and metsulfuron-methyl)).
Population
metsulfuron-methyl
sulfosulfuron
tribenuron-methyl
flupyrsulfuron-methyl
florasulam
fluroxypyr
bentazone
Ref
S
S
S
S
S
S
S
A
R
R
R
R
S
S
S
B
R
R
R
R
S
S
S
C
R
R
R
R
R
S
S
D
R
R
R
R
R
S
S
E
R
R
R
R
R
S
S
F
R
R
R
R
S
S
S
Cross resistant profile
Resistance ALOMY – practical findings
LWA (agricultural office) Ilshofen (G.Federolf)
• Resistance against IPU: since 1993
• against Ralon S (fenoxaprop-e): 1998
• against Atlantis (mesosulfuron+iodosulfuron): 2005
• against FOP‘s (not selective in cereala): 2002
• against DIM‘s: 2007
Black Grass Management
• If possible, remove occasional black-grass plants
before seeds shed, or spray off patches in June.
• Avoid spreading seeds to new fields in combines,
cultivators or in straw
• Place more emphasis on cultural control measures
(ploughing, crop rotation, spring cropping,
delayed autumn drilling, higher cereal seed rates)
• Don’t rely solely on ‘high risk’ chemistry e.g.
‘fop’/‘dims’ (e.g. fenoxaprop) or sulfonylurea
herbicides (e.g ‘Atlantis’)
• Remember that mixtures and sequences will slow,
but not stop resistance development
• If resistance is suspected, have a seed or plant
sample tested
Stephen Moss, Rothamsted, 2009
Risk evaluation Herbicides
positive
negative
Relatively broad spectrum of
MoA classes available
Not in Nordic
No new MoA classes in sight
Problems can be managed at
individual field level
GMO political tabu
Epidemiology „controlled“:
Rel. few individuals/ha
+/- localized
„Ideal“ MoA classes have
higher risk : ALS-Inh., ACCaseInh.
Changes in agronomic
practices can lead to favour
specific weed species
What can I do?
to prevent and manage problems….
Weeds – manage by field!
• Make sure no single species becomes predominant
in the crop rotation
– Agronomic practices: soil tillage, seeding date, rotation
– Effective use of herbicides in each season/crop
• When critical weed species becomes established
– Check/change crop rotation, practices
– Aim to reach levels of control as high as possible: mixtures,
sequences of herbicides; additives, optimum timing
– Intelligent rotation of a.i.‘s/MoA groups between the
rotational crops
– Integrate low(er) risk MoA: „soil herbicides“ in wi-cereals,
rape seed, sugar beets,…
What can I do?
when chemistry is vanishing….
Diseases and pests
• Hinder the outbreak of epidemics
– Crop rotation, agricultural means
– Crop varieties (resistance genes)
– application of fungicides/insecticides under optimal conditions ( prognosis
models, f.e. ProPlant)
• Preserve available actives as much as possible
– Aim for high efficacy: use rate, additives, weather
– Alternate or mix different MoA actives (include multi-site inhibitors) and
activity patterns (contact, systemic) in spray programs
– Specific integration of alternative MoA products in critical (= at risk for
resistance) segments: Pyrethroides and Neonicotinoides against Pollen
Beetle and Potatoe Beetle; Apple Codling Moth
News from the Chemical Industry?
• Fungicides
– Several Carboxamides (Succinat-Dehydrogenase-Inh.) for
horticultural and arable crops: Boscalid, Penthiopyrad
(Vertisan®), Bixafen, Isopyrazam,…
– Several novel a.i.‘s against powdery and downy mildews
• Insecticides
– Ryanodin-Receptor-Agonists: Diamides (IRAC Group 28)
• RYNAXYPYR®, CYAZYPYR®
– ACCase-Inh.: Ketoenoles (IRAC Group 23)
• Spirotetramat
• Herbicides
– Nothing new (MoA classes)
– Glyphosate/Glufosinate (in respective GMO crops)
– Multiple Tolerances: Glyphosate+ALS, +Dicamba (GMO)
Chemical renewal selective herbicides?
• Only 2 novel MoA-classes since 1980:
– ALS-inhibitors, 4-HPPD-inhibitors (triketones)
– Limited market potential due to crop selectivity
– Disappearance whole segments: Maize, Soya
• But the related alternative (Glyphosat tolerance) not
available in Nordic/EU
– The bar is set very high by the SU‘s!
• New actives from existing MoA-classes mostly
affected by both resistance mechanisms
– Pyroxulam, Pinoxaden
• Registerability in EU?
– Saflufenacil, Aminocyclopyrachlor, Aminopyralid
• No novel herbicidal MoA classes in sight until
2020, in the EU
ALS-inhibitors - outlook
• Relevance will increase further
–
–
–
–
Mid-term no new herbicidal groups available
New ALS-inh. enter same and new segments
Restrictions/withdrawel old herbicides (non-ALS)
Increase in generic product offerings
• Crops with modified ALS
– „conventional“ breeding
• „Clearfield“: Tolerance against Imidazolinones (imazamox)
• ExpressSun®: sunflowers tolerant against Tribenuron
– GMO-crops
• OptimumGAT® Stack: Glyphosate+ALS tolerance
Outlook and wishes
• Consider resistance management issues when
implementing EU 1107/2009 (revision of 91/414/EEC)
• End of the GMO tabu („Eco-imperialism“)
• Fast, reliable registration and approvals of alternative
actives
• Effective coordination of monitoring programs
• Effective communication and implementation of
preventative programs
– Who is ready/prepared to preventatively invest more
money/work?
• Plant breeding?
Thank you for your attention
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