Soybeans: Asian Soybean
Rust (Phakopsora pachyrhizi)
Pub 812: Field Crop Protection
Guide >
Pub 812:
Soybeans > Asian Soybean Rust
Field Crop Protection Guide 2011-2012, Order
2011-2012 publication
Table of Contents
- Integrated Pest Management Options
- Foliar Treatment
- pyraclostrobin – Headline EC
- azoxystrobin – Quadris
- propiconazole – Tilt 250 E
- azoxystrobin + propiconazole – Quilt
- prothioconazole - Proline 480 SC
- tebuconazole - Folicur 250 EW, Folicur 432 F
- trifloxystrobin + propiconazole - Stratego 250 EC
- Related links...
Integrated Pest Management Options
Foliar Treatment
Asian soybean rust is an invasive fungal disease. Scouting and
early detection are critical to managing this disease. The early
stages of the disease can be confused with other common foliar diseases
such as septoria brown spot, bacterial pustule, downy mildew, frog-eye
leaf spot and bacterial blight.
Numerous factors such as crop stage (R1-R6), yield potential, disease
risk or presence are critical components of the fungicide decision
process. Strobilurin fungicides such as Headline or Quadris are
protective products that stop spore germination and penetration
into the soybean leaf. The strobilurins have no effect on the fungus
once inside the leaf. Since the strobilurin group of fungicides
have no curative activity, do not make solo applications of a strobilurin
if any rust is present. The triazole fungicides such as Tilt and
Folicur have varying protective abilities and are usually considered
"early post-infection" fungicides. The post-infection
or curative abilities are limited, and the fungicides may not perform
well if 5%-10% disease is present in the lower crop canopy. Combination
products containing both a strobulurin and triazole fungicide such
as Quilt have preventative (pre-infection) and curative (post-infection)
properties.
Long periods of leaf wetness are needed for spore germination,
as well as temperatures between 15°C and 30°C and a high
relative humidity. Yield loss is very likely once rust can be found
in the mid-crop canopy. For these reasons, scouting, fungicide selection,
timing and application are critical to successful management of
soybean rust.
For further information on scouting techniques, sentinel plots,
thresholds, management options and emergency use registrations,
see OMAFRA Publication 811, Agronomy Guide for Field Crops,
as well as the Grain Farmers of Ontario website at www.gfo.ca.
| Active ingredient |
pyraclostrobin |
| Trade name |
Headline EC |
| Rate per hectare (product) |
400-600 mL per ha |
| Rate per acre (product) |
160-240 mL per ac |
| PHI* |
21 |
| Comments |
Ground and aerial application. Classified as a strobilurin
fungicide; use this product in a preventative fungicide program
(pre-infection). See label for resistance management strategy.
Maximum 2 applications/yr. |
| Active ingredient |
azoxystrobin |
| Trade name |
Quadris |
| Rate per hectare (product) |
500 mL per ha |
| Rate per acre (product) |
200 mL per ac |
| PHI* |
15 |
| Comments |
Ground and aerial application. Classified as a strobilurin
fungicide; use this product in a preventative fungicide program
(pre-infection). See label for resistance management strategy.
Maximum of 2 applications/yr. Re-entry possible once residues
have dried. |
| Active ingredient |
propiconazole |
| Trade name |
Tilt 250 E |
| Rate per hectare (product) |
500-750 mL per ha |
| Rate per acre (product) |
200-300 mL per ac |
| PHI* |
30 |
| Comments |
Ground and aerial application. First application should be
made at the first sign of disease, followed by a second application
14 days after the first application if environmental conditions
are favourable for disease development. Good spray coverage
and canopy penetration are important for best results. See label
for resistance management strategy. Maximum 2 applications/yr. |
| Active ingredient |
azoxystrobin + propiconazole |
| Trade name |
Quilt |
| Rate per hectare (product) |
1.0-1.5 L per ha |
| Rate per acre (product) |
400-600 mL per ac |
| PHI* |
30 |
| Comments |
Ground and aerial application. First application should be
made at the first sign of disease, followed by a second application
14 days after the first application if environmental conditions
are favourable for disease development. Good spray coverage
and canopy penetration are important for best results. See label
for resistance management strategy. Maximum 2 applications/yr. |
| Active ingredient |
prothioconazole |
| Trade name |
Proline 480 SC |
| Rate per hectare (product) |
210 mL per ha |
| Rate per acre (product) |
85 mL per ac |
| PHI* |
20 |
| Comments |
Ground application only. Apply when first
symptoms of disease can be found or the risk of infection is
imminent. Maximum 1 application/yr. 24-hr re-entry period. |
| Active ingredient |
tebuconazole |
| Trade name |
Folicur 250 EW |
| Rate per hectare (product) |
375-500 mL per ha |
| Rate per acre (product) |
152-200 mL per ac |
| PHI* |
20 |
| Comments |
Ground and aerial application. Apply when first symptoms of
disease can be found or the risk of infection is imminent. Use
the higher rate when disease pressure is severe. Use a minimum
of 100 L/ha water for ground application, 47 L of water for
aerial application. The use of non-ionic surfactant (Agral 90
or Agsurf) is NOT required as it is built into the formulation.
Maximum 1 application/yr. 12-hr re-entry period. |
| Active ingredient |
tebuconazole |
| Trade name |
Folicur 432 F |
| Rate per hectare (product) |
220-292 mL per ha |
| Rate per acre (product) |
90-118 mL per ac |
| PHI* |
20 |
| Comments |
Ground and aerial application. Apply when first symptoms of
disease can be found or the risk of infection is imminent. Use
the higher rate when disease pressure is severe. Use a minimum
of 100 L/ha water for ground application, 47 L of water for
aerial application. Always use a non-ionic surfactant such as
Agral 90 or Agsurf at 0.125% vol/vol. Maximum 1 application/yr.
12-hr re-entry period. |
| Active ingredient |
trifloxystrobin + propiconazole |
| Trade name |
Stratego 250 EC |
| Rate per hectare (product) |
500 mL per ha |
| Rate per acre (product) |
200 mL per ac |
| PHI* |
20 |
| Comments |
Ground and aerial application. Begin applications preventatively
from early flowering (R1) to complete pod fill (R5) when rish
of rust infection is high. Use 100-200 L/ha of water for ground
application, 50 L/ha for aerial application. Maximum 2 applications/yr.
12-hr re-entry period. |
Related links...
