Seed bank obsession Why?

Peter Newman, AHRI

Benefits of low seed bank

Profitable crops.

Fewer weeds.

Benefits of low seed bank

Farmer calls the shots, not

the weeds.

Benefits of low seed bank

Herbicide longevity

Population size X

genetic diversity

Weed Seed Bank

Weed Seed Bank

TGOD

Weed Seed Bank

TGOD

Weed Seed Bank

TGOD

Weed Seed Bank

TGOD

Low Seed Bank

Obsession

Roberto Busi, AHRI

Creating a cross resistant monster

Sakura – year 1

Susceptible ryegrass (VLR 1) – 90% control Multiple resistant ryegrass (SLR31) – 62% control

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Dose Label rate

Her

bic

ide

do

se (

%)

Sakura low dose research

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Year 1 Year 2 Year 3 Year 4

Her

bic

ide

do

se (

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Label rate

Sakura resistant ryegrass

The result?

Cross resistance

Sakura

Cross resistance

Sakura Boxer Gold

Cross resistance

Sakura Boxer Gold Avadex

Sakura 50g

Boxer 1000g

Trifluralin

480g

Susceptible SLR31 SLR31

4 selections with Sakura

It works both ways

Boxer Sakura

M2 W.A. wheatbelt 3 selections with

Boxer Gold

Sakura dose response

What does it all mean?

1. Likely – metabolic resistance from Group A / B 1980’s

Metabolic resistance to Sakura / Boxer in low dose work

------------- Metabolic resistance level

1975 1995 2010 ?

SU’s Fops

Trifluralin Clethodim

Sakura Boxer Gold

Avadex

Some herbicides more prone to metabolism based resistance than others

No metabolic resistance so far

Glyphosate Clethodim Atrazine* Trifluralin

Propyzamide

Some herbicides more prone to metabolism based resistance than others

Metabolic resistance confirmed

Fops SU’s Imi’s

Sakura Boxer Gold

Avadex

No metabolic resistance so far

Glyphosate Clethodim Atrazine* Trifluralin

Propyzamide Lab

Qin Yu, AHRI 33 group A (Fop) resistant populations

Target site 91%

of resistant populations

Metabolic 80%

of resistant populations

70%

2. Low dose selection for resistance worked both ways

Low dose Sakura Boxer resist

Low dose Boxer Sakura resist

3. Trifluralin resistance mechanism.

???

4. No cross-resistance between the boxes

Trifluralin (D)

Sakura (K) Boxer Gold

(J,K) Avadex (J)

Propyzamide (D)

1. Herbicide rotation

Trifluralin

Sakura

Propyzamide Boxer Gold

Avadex

2. Seed bank management

Because new herbicides, from novel groups,

may fail from the word go

Due to metabolic resistance

------------- Metabolic resistance level

1975 1995 2010 ?

SU’s Fops

Trifluralin Clethodim

Sakura Boxer Gold

Avadex

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Brome grass

self pollinating

HWSC

Michael Walsh, AHRI – 9 trials 2008

HWSC complements herbicides

Walsh et al. Weed Tech. 2013 0

5

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30

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

An

nu

al ryeg

rass (

pla

nts

/m

2)

Plus HWSC

Minus HWSC

Peter Newman and Michael Walsh

Bale Direct Chaff cart Narrow windrow burning

Harrington Seed Destructor

5 Options

Chaff Deck

$10K - $35K

$78K

$12K - $14K

Chaff lining Mic Fels, Esperance

Chaff dump from last harvest

Winter burning??

Ryegrass

100%

3-6%

Ryegrass

100%

15-20%

Two year old rotting

chaff

Two year old chaff dump

- competition + competition

40 kg/ha Wheat seed rate

160 kg/ha Wheat seed rate

Binnu trial 2012 – Peter Newman (DAFWA trial, GRDC funded)

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Rye

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eed

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Seeding rate

Newman (DAFWA) 2012 - Ryegrass seed set /m2 Nil pre-em

Glen Riethmuller 27 year trial – stubble retained

0.7

0.4

19

77.5

0 10 20 30 40 50 60 70 80 90

90 mm

180 mm

270 mm

360 mm

2013 - ryegrass seed set /m2

90 180 27

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50100

200400 Row Spacing mm

Rye

gras

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eads

/m2

Seeding rate kg/ha

David Minkey

7" Rows

14" Rows0

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30 kg/ha60 kg/ha

90 kg/ha120 kg/ha

Panicles /m2

1999 - Brome / ryegrass seed heads /m2

7" Rows

14" Rows

More yield

1% / inch

More crop, less weeds

Win Win

Crop Orientation 50% reduction in weeds for free

Catherine Borger Department of Agriculture & Food WA

East-west

51% less ryegrass seed by sowing east-west

North-south

Wyalkatchem UA40

Competitive cultivars Eradu 2011

More cost effective to achieve high crop competition through row spacing and

row orientation than through just increasing seeding rate

We are no-till farmers, but…

Treatments 2007

Untreated

Surface lime 2 t/ha

Mouldboard plough

2t Lime + MBP

MBP + 2t Lime

1t Lime + MBP + 1t Lime

Dr. Steve Davies

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2014 Dr. Steve Davies

Barley

grain

yield

2014

Dr. Steve Davies

Ryegrass biomass 2014

Dr. Steve Davies

More crop, less weeds

Wild Radish

@peterdnewman

On-line learning from AHRI

Thank you

The art of narrow windrow burning

1. Harvest

Low

2. Harvest

Low

3. Harvest

Low

Grass fire index 2 to 10

Light cross wind

Light up every 200 to 400m

Massive windrows? Be patient – wait til 11th hour