Fungicide Apps for reducing DON and FHB: Do It

Fungicide Apps for reducing
DON and FHB:
Do It Right (or not at all)!
Dr. Dave Hooker, U of G Ridgetown Campus
dhooker@uoguelph.ca
Twitter: cropdoc2
Dr. Art Schaafsma (UGRC)
Helmut Spieser (OMAFRA)
Albert Tenuta (OMAFRA)
Peter Johnson (OMAFRA)
Sprayer Rodeo – June 2002
UTC
Caramba
Prosaro
Both Prosaro and Caramba are
excellent fungicides, but they only
suppress FHB and reduce DON by
about 50% with the BEST application.
If coverage could be 100%, then
research shows efficacy may be close
to 100%. Next to timing, application
technology is the limiting factor for
greater suppression!
~50% suppression
@ Best application
@ Optimal timing
Back-Fwd
Turbo FF TeeJet
TwinJet
Conventional
Turbo FF TeeJet
Conventional
Turbo FF TeeJet
Sprayed 2x – Opposite Directions
Most of our application
technology work started in the
late 1990s with dye and UV
light. In 2002, we devised a
replicated expt to compare
airplane and helicopter rigs
Figure 2.
with ground applicators
We used water sensitive
papers to evaluate applicator
performance. These were
orientated around vials in the
field to mimic a wheat head.
4 reps x 45 papers per sprayer.
Spray Coverage vs Application Method
Aerial apps volume = 4 GPA, vs. 20
GPA for ground sprayers. We used
copper sulphate at the same per-acre
rate in each sprayer and analyzed the
papers for copper.
BEST: Back-Fwd design;
FAIR: Aerial=rest
Airplane
Chopper
Airplane
Chopper
XR11002
Sprayed 2x
XR11002
Sprayed 2x
XR11004
XR11004
TwinJet
Nozzles
TwinJet
Nozzles
Backward
Forward
Nozzles
Backward
Forward
Nozzles
The butted edges always faced the rear of
the sprayer. Blue dots represent coverage.
Yellow represents no coverage. Spikelets on
a wheat
Figure
4. head would not be protected here.
0
20
% Average Coverage
40
Rodeos in the 2004-2006
tested other sprayer
Back-Fwd
configurations
Turbo TeeJet
Back-Fwd
Air-Induction
Fwd Only
Turbo TeeJet
Back Only
Turbo TeeJet
Fwd Only
Turbo FloodJet
Back Only
Turbo FloodJet
Twin Cap
Cone
TwinJet
2004 and 2005 Rodeos
Alternating
Turbo Flood
Alternating
Turbo Flood
TeeJet Duo
Nozzle Configurations Compared
Spray Distribution on “Heads” vs Nozzle, 2004
Front
Left
Back
Right
Cone 12 mph
Forward Only FF 12 mph
FWD-BACK TT11004
12 mph
TurboFlood
Alternate on Boom
12 mph
TwinJet
12 mph
Note the
variability of
coverage on
each “side” of
the wheat
head
Backward Only FF 12 mph
Back-Fwd AI tips 12 mph
□
□
TwinJet 12 mph
Backward-Forward FF 12 mph
Alternating Turbo FloodJet 12 mph
Back-Fwd and the Alternating
Turbo FloodJet™ nozzles
resulted in the best coverage
TwinJet nozzles approx 50%
less coverage than the 2 on the
left. 50% less control?
0
All tmts applied at 20 GPA
NDSU Recommendations
10
20
30
40
50
% actual coverage
NDSU Recommendations
Barley
Wheat
Fwd Only
Turbo TeeJet
cut and pasted
NDSU, Halley et al. (2004)
US recommendation shows poor
coverage on one side of the fwd-only
design, similar to our data, but they still
recommend.
Increasing boom heights over canopy reduces coverage, but the “best” nozzles at
high boom height are Boom
still better
than theAffects
TeeJet Duo
or TwinJet at optimal heights.
Height
Coverage!!
top view
side view
30
Back-Fwd 30
Flat Fan
20
20
Alternating 30
Turbo
Flood
20
10
10
10
0
0
Ideal High
8”
16”
Ideal High
8”
16”
Source: Tom Robinson, Syngenta. UK
30
TeeJet
Duo
20
10
0
0
Ideal High
8”
16”
30
Back-Fwd
AirInduction
20
TeeJet Duo
0
Ideal High
16”
32”
TwinJet
Lower boom height = less wind effects. Winds >10
kph result in painting one side of heads. Maintain
water volumes ~20 GPA for less wind effects.
Ideal boom height for B-F nozzles and TurboFlood
= 8-12” above canopy
10
Ideal High
16”
32”
Even wash the outside of the sprayer!!!
Résidue d’herbicide dans
les
Injured
Wheat
cuves
Clean
End
Caps!
Injured
Wheat
• Le champ de Nappierville montrait des
symptomes de contamination par
l’atrazine (par friction sur les roues et
chassis du tracteur)
Healthy
Wheat
Photo: Luc Bourgeois (Bayer CropScience)
Photo: Luc Bourgeois (Bayer CropScience)
Sprayer Check List
□
□
□
□
□ Ground (best) vs aerial (good)
□ Sprayer cleanout (critical!)
Backward-Forward Nozzles or Turbo FloodJet™
alternating along boom
Keep the 2 nozzle configurations 30 cm (8-12”)
above canopy
Backward-Fwd nozzles 15 degrees from horizontal
Maximize water volume (20 GPA) improves coverage
Fungicide Efficacy on DON vs. Level
DON (ppm)
OCCC Belmont AND Nairn 2013
These cultivars are
highly susceptible to
DON accumulation;
50% suppression of
DON still feed grade!
Moderately tolerant
cultivars + fungicide =
Quality wheat in
“epidemic conditions”
***
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*
□ What’s your custom applicator doing?
Cultivar Ranks from Highest to Lowest DON in Untreated Checks (UTC)