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SAKURA pre-emergent herbicide:
Registered for use in wheat (not durum wheat) and triticale at 118 g/ha.
Registered for control or annual ryegrass, barley grass, silver grass, annual phalaris, and toad rush.
Registered for suppression of brome grass (great brome only) and wild oats.
Sakura is a Group K herbicide containing the active ingredient pyroxasulfone.
Sakura can be applied up to 3 days before incorporation.
Sakura provides prolonged residual soil activity under good soil moisture conditions.
Sakura works primarily through root uptake.
Sakura® is a Registered Trademark of Kumiai Chemical Industries Co. Limited
http: www.sakuraherbicide.com.au
Sakura at a glance:
SAKURA - the positives in a patchy start:
• Sakura applied prior to dry sowing generally performed well. i.e. pre 7th May 2013 seeding.
• Sakura applied from late May onward activated in July with the germinating weeds providing good control. i.e. Mukinbudin
• Sakura activated after July rainfall and controlled later emerging grass weeds, even where some of the early weeds had escaped.
• Sakura + trifluralin mixtures worked well under a drying top soil (“The Grey Zone”) 10-20th May.
http: www.sakuraherbicide.com.au
Understanding stubble & soil binding of pre-emergent herbicides used for ryegrass control in winter cropsToday’s presenter is: Dale Shaner, USDA (retired)GRDC Webinar 13/12/13
Release of herbicide from surface residue with rainfall:• Trifluralin and prosulfocarb are not washed from residue surface with rainfall.• Metolachlor, dimethenamid and pyroxasulfone can be washed from surface
residue.
5 mm 10 mm 15 mm0
10
20
30
40
50
60
70
80
90
% pyroxasulfone (Sakura) washed from residue after rainfall
% w
ash
ed o
ff
The impacts of stubble without following rain are an issue for ALL pre-emergent herbicides
Use high water rates if the stubble cover is likely to be problematic
Prostrate stubble
Standing stubble/
furrow concentration
Pasture - compacted
SAKURA: Importance of rainfall after sowing
Dry soil – awaiting activation
Dry top soil,
moist below
Sakura – effective application video
Moist soil and incorporated
http: www.sakuraherbicide.com.au
Actively growing weeds but inactive herbicide = reduced performance
The impacts of stubble without following rain are an issue for ALL pre-emergent herbicides
Use higher water rates if the stubble cover is likely to be problematic
Prostrate stubble Standing stubble/
furrow concentration
Pasture - compacted
2013 Key factors influencing performance:
Seed bank (high density), especially coming out of pasture in 2012. Stock pulverising stubble and pushing weed seeds into soil profile.
Following a germination event 2-10 days after spray application & seeding. “The Grey Zone”
Stubble (not washing through) in time to be active in the soil where weeds are germinating.
Insufficient rainfall within 7-10 days after application to facilitate movement of Sakura into the weed seed zone ( top 2.5 to 3 cm).
http: www.sakuraherbicide.com.au
Sakura needs to be “Present for the Germination event”
SAKURA: GETTING THE BEST POSSIBLE RESULTS
The checklist:
Use Sakura in rotation with other chemical and non-chemical control options
Mix Sakura in the tank first (pour slowly) and ensure it is fully dispersed before adding other productsMaintain good agitation before and during spraying.
Apply Sakura at full label rates
Apply Sakura evenly to uncultivated soil that isn’t too ridged or cloddyCultivation before Sakura application (including “tickle”) will bury weed seeds, or stimulate increased emergence.
Use high water rates if the stubble cover is likely to be problematicStubble cover or other plant residues of greater than 50% can reduce the effectiveness of Sakura.Pulverised pasture stubble ‘blanketing’ the paddock or only partially burned windrows will be more problematic than crop stubble, even if it’s prostrate.
Ensure emerged weeds are controlled by an effective knockdown herbicide before planting the crop
Sakura needs to be present when weeds germinate for most effective uptake Sakura works well for dry seeding, but control will be compromised if Sakura is applied onto moist soil without follow-up rain. For application after a weed germination event with minimal rain forecast, tank-mixing with trifluralin may improve control.
Incorporate Sakura by sowing (IBS) using either knife points and press wheels or narrow points and harrows within 3 days of application
http: www.sakuraherbicide.com.au
Things we know about sclerotinia in canola
What do we face?• Canada typically flower for 4-5 weeks, Australia 6-8+ depending on
variety.• All canola varieties are susceptible and bigger healthier canopies
can increase the risk.• Liquid N fertiliser applications during flowering may increase severity
of the disease (increasing canopy bulk).• Main stem infections cause greater yield loss than lateral ones.The disease:• Sclerotes survive for long periods in the soil (~6 years).• When the soil temperature is ~15°C and soil becomes saturated
apothecia will emerge in 7-10 days and will keep emerging while conditions are favourable (high humidity).
• A single sclerote can produce up to 15 apothecia.• Optimal temperature for lesion development is 20-25°C with
primary infection generally from petals but secondary infection can occur from contact with infected leaves or stems.
• Sclerotinia needs 24-36 hours of continual leaf wetness to infect.
Assessment of flowering stages
Flowering stages should be assessed on the main stem:
10% = 10 flowers open20% = 14-16 flowers open30% = 20 or more flowers open40% = 30 or more flowers open50% = All flowers are open or have opened, crop is at its most intense yellow (full flower)60% = Flowering intensity is beginning to decline
http: www.bayercropscience.com.au or Think twice – Sclerotinia”
Mean
Henty
(NSW
)
Dookie (V
ic)
Wag
ga W
agga
Dookie (V
ic)
12 Chapman
Valley
(WA)
Howlong (Vic)
Howlong (Vic) Vic
Junee (N
SW)
Dookie (V
ic)
11 Rudd's Gully
(WA)
11 Chapman
Valley
(WA)
11 Chapman
Valley
(WA)
13 Geraldton (W
A)
13 Green Ran
ge (W
A)
11 Straw
berry (
WA)
Tarcu
tta (NSW
)
Boorowa (
NSW)
Cowra (N
SW)
13 Narngu
lu (WA)
Henty
(NSW
)
Holbrook (
NSW)
Dookie (V
ic)
Burrumbuttock
(NSW
)
Walb
undrie (N
SW)
90
100
110
120
130
140
150
160
170
180
118
100 102 102 103 104108 109 110
112 114 114 116 116118 119 120 121 122
126 127
136 138 139 139
172
% u
ntre
ated
yie
ld
2011-13 Prosaro control of sclerotinia in canolaAverage % yield increase over untreated (100% = 1.90 t/ha)
18% average yield increase (350 kg) over untreated across 25 commercial trials.
http: www.bayercropscience.com.au or “Think twice – Sclerotinia”
Economic return at ~$500 tonne
1st 5th 9th13th
17th21st
25th29th 2nd 6th
10th14th
18th22nd
26th30th 3rd 7th
11th15th
19th23rd
27th0
5
10
15
20
25
30Geraldton airport daily rainfall and max. daily temp.2013
rain
fall
mm
/ te
mpe
ratu
re °C
July August September
Spray timings – spray to the conditionsProsaro yield response in the Midwest13WE02: Control of Sclerotinia in Hyola 404RR, Narngulu, WAApplication (25/7) = 30% flower
Location Narngulu
Variety Hyola 404RR
Flowering length 6-8 weeks
Yield t/ha response
320 kg/ha$125.85 ROI
Key messages:• Apothecia found on 25th July• 30% spray resulted in 27% yield response• 2 spray strategy starting at 30% ~3 weeks
apart may have provided improved yield
Protection period~3 weeks
Apothecia
Treatment 03/10/2013
% Incidencet/ha
% untreated
Costs $/ha% Oil
gross $/ha
ROI $/ha % Sclerotes by weight
Untreated 53 a 1.19 100 45.2 $604.14 0.44
Prosaro 375 mL/ha 14 b 1.41 118 $26.25 45.4 $712.97 $76.58 0.08
Prosaro 450 mL/ha 7 b 1.51 127 $29.70 45.8 $764.70 $123.06 0.1
http: www.bayercropscience.com.au or “Think twice – Sclerotinia”
Prosaro significantly reduced disease severity and incidence to maintain yield potential.
Fungicides: Getting the best results for sclerotinia in canola
The checklist:
Single spray:If opting for a single spray don’t apply too early. The best timing is generally ~20-30% flowering dependent on conditions.Later application at 30-50% timings can be beneficial in longer seasons.
Other considerations:Air / soil temperature and rainfall are as important as flowering stage.Increased water rates are recommended – 100 L/ha is good.When plants are fast growing the window of protection will be shorter i.e. at 20% compared to 40% flowering.
Multiple Sprays:Longer flowering varieties may require 2 applications under high disease pressure.Spray timings should consider favorable conditions for disease development not just
crop stage.
Future developments: Bayer CropScience continues to evaluate new chemistry for sclerotinia control.
http: www.bayercropscience.com.au or “Think twice – Sclerotinia”
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