Murray Scholz 2008 Nuffield Australia Scholar

To my wonderful family Emma, Ben, Tara and Georgia for their love patience, support and understanding while I spent 2008 travelling.

1640 haCulcairn SW NSWNo-till & Continuous croppingWeeds are one of our largest management issues

Weeds cost Australian farmers $1.5 billion a year in weed control activities & $2.5 billion in lost production

Weeds CRC 2004

Grown in North America since 1996Canola, soybeans, corn, cotton,

alfalfa & sugar beetsIn 2006 approximately 100 million

hectares of GM crops were grown in 22 countries, of which 70% herbicide resistant

95% of herbicide resistant GM crops are Roundup Ready

Western CanadaRapid uptake of herbicide resistant GM Canola Grown in a rotation with wheat barley & peasHybrid varieties have delivered higher yields and profits

Herbicide Weed biomass (kg/ha)

Net return ($/ha)

Glyphosate x 1 296 $354

Glyphosate x 2 136 $321

Ethalfluralin (E)* 1393 $286

Sethoxydim (S) + Ethametsulfuron (Eth)

1182 $245

E + S + Eth + Clopyralid

410 $165

*Ethalfluralin was applied to the soil surface in the fall. Adapted from O’Donovan et al. (2006)

In the corn belt rotation of soybeans/corn95% of soybeans herbicide resistant GMIncreasing amounts of continuous Roundup ready crops

“Roundup Ready technology made ordinary farmers into good farmers........but only for a while”

Phil StahlmanWeed scientist Kansas State University

CONVENTIONAL HERBICIDES

12 years continuous trialConventional herbicides only½ rate of glyphosate onlyFull rate of glyphosate onlyAll no-tillWeed shift has happened Resistance is close

GLYPHOSATE FULL RATE GLYPHOSATE HALF RATE

ConventionalFull tillage, pre-emergent herbicide incorporated, 3-5 herbicides applied at least 3 times in crop ; 2-3 in crop cultivations

Glyphosate - Resistant CultivarNo-till, glyphosate knock down, up to 4 post emergence glyphosate applications

Increase complexity and costs of weed management in cotton and soybeanCompromise conservation tillage in the short term and possibly the long-termMay precipitate a cascade of resistance in post emergence broad-leaf herbicides

Total reliance on glyphosate for weed controlLack of rotationThe US farm bill Monsanto’s insistence of selling new GM technologies with the Roundup Ready system

1940 1950 1960 1970 1980 1990 2000 2010

Phen

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Din

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Gly

phos

ate

Glu

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Fops

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SUs

Imis

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PPO

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Changing from a risk based to hazard based systemPossibility that 85% of pesticides will be removed from the marketPotential to massively reduce production

Lower productionWeeds resistant to cultivationAddicted to diesel

Moral of the story, choose your technology and don’t throw stones because nothing is perfect

Roundup ready canola doesn’t replace Integrated Weed Management, it is another toolMaintain the accreditation processGrow canola only once every 3-4 yearsBudget to use glyphosate twice in cropMonitor crops for glyphosateresistance

“Tell Australian farmers to rotate their crops and their herbicides”

Herb Matson, Farmer Colby Ks