NEW INFORMATION, GENETICS AND STRATEGIES

TO CONTROL HERBICIDE RESISTANCE

Peter Smith

University of Guelph

Herbicide Resistance

• Its seemingly on everyone’s radar now …no panic though

• CWSS (Edmonton Nov 2015)

• WSSA (San Juan Feb 2016)

www.weedsummit.ca

suspect screening

24 hrs

Unique worldwide

*

WorldwiDE

GlyphosaTE

34 currently known spp.

CanadA

Ontario

Horseweed (Conyza canadensis) aka Mare’s tail or Canada fleabane

COMMON RAGWEED

• Summer annual

• Competitive

• Male vs female parts leads to pollen shed and huge genetic diversity

• Large and heavy seed

• Dormant seed

Canada fleabane

• Winter annual or summer annual

• Competitive

• Self pollinating: limited genetic diversity within a population

• Light seed with pappus (parachute) therefore highly mobile

• Limited seed dormancy

Resistant fleabane

Glyphosate Resistant

Multiple Resistant

Image compliments of Chris Budd

Independent points of selection: Eric Page

HERBICIDES WORK

BIOTECH MAKES IT ‘EASIER’

Bromoxynil Tolerant Canola

POAST Protected

Corn

mid 1990 ‘s

Bromoxynil Tolerant Canola

POAST Protected

Corn

mid 1990 ‘s

Most widely used

herbicide EVER

Broad spectrum

Systemic Low cost

Efficacious

Advantages of glyphosate

‘Bad’ things do happen

So what’s ‘bad’ in 2016?

Getting the word out

Nufarm

World’s largest manufacturer of 2,4-D New active ingredients in development with excellent fleabane control New tank mix combinations Corn, soybeans, cereals

valent

Flumioxazin heavy use preemergence in USA soys for: waterhemp and palmer amaranth Group 2 and 5 biotypes of lamb’s-quarters and pigweed Fierce (flumioxazin plus pyroxasulfone) Corn, soybeans, cereals

Syngenta / bayer

MGI

Mesotrione Glufosinate Isoxaflutole

Seed traits in soybeans

FMC

New active ingredients in development New tank mix combinations Burndown and residual in corn, soybeans, cereals

Bayer cropscience

Liberty Link corn, soybeans and canola Broad spectrum Non systemic Non residual Balance GT Beans Tolerant to ‘Converge’ herbicide and glyphosate Broad sectrum Residual PRE applications 2017 or 2018 launch

Bayer cropscience

Leading edge in safener technology Developing safened dicamba Allows greater crop safety with soys and corn Application window extended from 5 lf to 8 leaf corn Problem weeds too… VICCR, MEDLU, ERICA etc.

basf

STEWARDSHIP driven

Banvel owners

Grow the best crops possible

Alternative methods of weed control

Be mindful of weed spectrum

Multiple modes of effective action (MMOEA)

MMOEA in a single year are far better at delaying resistance than herbicide rotation

* University of Illinois

dupont

Sulfonylurea Tolerant Soybeans BOLT herbicide in USA More tolerance, better weed control Way out there… 2020?

• Resistance to 2,4-D in corn and soybeans, 2017?

Banvel 2,4-D MCPA Estaprop Distinct

Assure Excel Poast

• Resistance to the ‘fops’ but not the ‘dims’

Stacked with glyphosate Volunteer corn control

Dow agrosciences

So what’s available now?

New for the 2016 growing season…

monsanto

• Registered Feb 3, 2016

• Gene from a bacteria causing ONLY dicamba tolerance in DT soybeans

Banvel 2,4-D MCPA Lontrel Distinct

The dicamba molecule…

Banvel II, Distinct, Hawkeye Power, XtendiMax Strengths: Excellent control on most broadleaf weeds including: GR Canada fleabane (emerged) GR ragweeds – common and giant (emerged) GR waterhemp (PRE and POST) Pre and POST emergence applications Limited resistance worldwide Minimal grass activity though

The dicamba molecule…

Dicamba alone will control some weeds that are

naturally tolerant to glyphosate!

Hmmmm…

Problem weeds…

Black medick Related to alfalfa Summer annual Low growing

Problem weeds…

Wild buckwheat Summer annual Low growing

Problem weeds…

Tufted vetch Perennial Vine like

Problem weeds…

Perennial Sowthistle Late emerging

Problem weeds…

Canada thistle Perennial Late emerging

Problem weeds…

Waterhemp Pigweed species Summer annual Male or female plants Limited presence in ON

Some data then…

0 20 40 60 80 100

glyphosate

gly + dicamba 300

gly + dicamba 600

Control (%) 4 WAA

Preplant Postemergence Preplant fb POST

Xtend vs GR ragweed

Sikemma

GR Giant ragweed

weedy check glyphosate (1X)

glyphosate + dicamba Joe Vink

ab

abc

cde

abc

bcd

f

0 20 40 60 80 100

glyph + dicamba (600); glyph + dicamba(300)

glyph + dicamba (300); glyph + dicamba(300)

glyphosate; glyph + dicamba (300)

glyph + dicamba (600); glyphosate

glyph + dicamba (300); glyphosate

glyphosate; glyphosate

Trea

tmen

t

% control 56 DAAn=2

Xtend vs GR fleabane

Particle drift vs vapour drift

Droplet size (tactile variables)

Wind @ spray

New Formulations Heat even 1-2 DAT

so what of drift?

Novel crops and herbicides will help out some

Sprayer cleanout

Photo source Monsanto demo plots: Chatham, Ontario

• Even trace amounts have big impacts

• These are rinses with water, sprayed over conventional soybeans

• Soybeans? No problem

• Volunteer Enlist corn is resistant to ‘FOP’ herbicides …need ‘DIM’ herbicide for control

• Antagonism issues for corn control

And volunteers?

Will New HR Crops Succumb to Resistance?

They say there won’t be

glyphosate resistance,

Doc…

Hindsight Marty…

back in 1990

Dicamba, 2,4-D suite, MCPA, 2,4-DB etc

(30 species worldwide as of 2016)

• Wild carrot (Ontario) 1957

• Wild mustard (Manitoba) 1990

• Common hempnettle (Alberta) 1998

• False cleavers (Alberta) 1998

auxinic resistance exists

• Xtend soybeans are now available

• More options are coming

• Need to use very sensibly

In summary…

François Tardif

Allan Kaastra Jamshid Ashigh

Joe Vink Julie Schipper James Ferrier

Chris Budd Rob Miller

Mike Cowbrough

thanks