michael walsh - plant health summit
TRANSCRIPT
Harvest weed seed control Developed in response to
herbicide resistance Because of potential to target
weed seeds
Target seed production at harvest
Weed species Retained seed* (%)
Lolium rigidum 88
Raphanus raphanistrum 99
Bromus spp. 73
Avena spp. 85
* Seed above harvester cutting height (15cm)
Weed seed retention during wheat crop harvest
Time post wheat crop maturity (d)0 7 14 21 28
Seed
rete
ntio
n (%
)
0
20
40
60
80
100
Lolium rigidumBromus spp.Raphanus raphanistrum Avena spp.
Lot feeding Autumn burning
Chaff carts
Up to 85% of annual ryegrass and wild radish seed removed
Grazing
Chaff collection Lance Turner
Developed conveyor belt chaff transfer system - Easy attachment
- Shorter burning times
Estimated 200 new chaff carts in WA since 2013
Glenvar Bale Direct System Up to 95% of annual ryegrass seed removed in baled
harvest residues Financial opportunity where residue is a problem and
there is a market for straw
Chaff lining - Confine chaff on a tramline or in a row
- Hostile environment for weed seeds
- Leave undisturbed
Annual ryegrass seed survival Seed packets placed under chaff at harvest then retrieved prior to seeding
Survival
(%) Chaff (t/
ha)
Canola 2 31
Wheat 74 19
Barley 3 18
Survival
(%) Chaff (t/
ha)
Canola 6.5 14
Wheat 36 16
Chaff on tramline Chaff in narrow row
Cagemill results >90% kill of annual ryegrass seed
No effect of chaff type
0
20
40
60
80
100
700 900 1100 1300
Seed
sur
viva
l (%
)
Cagemill speed (rpm)
Comparison of HWSC systems Narrow Windrow Burning, Chaff Carts and HSD
Replicated treatments at 25 sites
Lolium emergence in autumn
Treatment Reduc-on in Lolium emergence
(%) HSD 57 Chaff cart 56
Narrow windrow burn 57
LSD (P=0.05) 9
Weed species SE
Annual ryegrass 93 0.7 Wild radish 99.8 0.2 Wild oats 99.9 0.1
Brome grass 99 0.2
Efficacy of iHSD
0
5
10
15
20
25
30
35
40
45
50
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Annu
al ryegrass (plann
ts/m
2 )Focus paddocks -‐ surviving ryegrass in spring
Plus HWSC
Minus HWSC
The value of HWSC
0
500
1000
1500
2000
2500
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Ryegrass se
ed pr
oductio
n (seed/m
2 )Focus paddocks -‐ Estimated ryegrass seed set
Plus HWSC
Minus HWSC
The value of HWSC
HWSC is an accepted practice Adopted by approx. 40% Australian crop producers
Cumulative adoption curves for narrow windrow burning by agro-‐ecological zones 100
90
80
70
60
50
40
30
20
10
0 2000 2002 2004 2006 2008 2010 2012
NSW Central NSWNW/Qld SW Qld Central SA Vic Bordertown -‐ Wimmera Vichigh rainfall and Tas grain WA Eastern WA Northern
NSWNE/Qld SE NSWVic Slopes SA Midnorth -‐ Lower Yorke Eyre SA Vic Mallee WA Central WA Sandplain -‐ Mallee
% of gr
owers