Cereals: Wheat: Powdery
Mildew (Erysiphe graminis f. sp. tritici)
Pub 812: Field Crop Protection
Guide >
Chapter
4: Cereals > Wheat: Powdery Mildew
Field Crop Protection Guide 2011-2012, Order
2011-2012 publication
Table of Contents
- Integrated Pest Management Options
- Foliar Treatment
- pyraclostrobin – Headline EC
- propiconazole – Tilt 250 E, Bumper 418 EC
- tebuconazole – Folicur 250 EW, Folicur 432 F
- trifloxystrobin + propiconazole – Stratego 250 EC
- prothioconazole + tebuconazole - Prosaro 250 EC
- Related links...
Integrated Pest Management Options
Seed Treatment
The fungus is very susceptible to weather conditions that promote
drying of the crop environment, such as hot, dry sunny weather.
Management includes the use of tolerant varieties, crop rotation,
tillage, and fungicides. Consult with your seed company and the
Ontario Cereal Crops Committee Variety Trials Results at www.gocereals.ca
for variety profiles.
See OMAFRA Publication 811, Agronomy Guide for Field Crops,
for thresholds and more information
| Active ingredient |
triadimenol |
| Trade name |
Baytan 30 |
| Rate (product) |
50-100 mL per 100 kg seed |
| Comments |
Use higher rate for winter wheat. Must be diluted with water
prior to treatment of seed to ensure uniform coverage. Treated
seed will sometimes emerge more slowly than untreated seed.
Avoid late seeding of winter cereals. Do not graze or feed livestock
on treated areas for 40 days after planting. |
Foliar Treatment
Foliar fungicide applications may be necessary if disease levels
will result in yield losses and/or a susceptible variety has been
used. Consult with your seed company and the Ontario Cereal Crops
Committee Variety Trials Results at www.gocereals.ca
for variety profiles. Thresholds for fungicide applications differ,
depending on the age of the crop. If 5%-10% of the lower leaves
are infested early in the season, control is warranted. This may
limit later infection. Later in the season, powdery mildew symptoms
on the flag leaf (1% of leaf) and the second leaf (3%-5% of the
leaf) require immediate attention, especially if prolonged wet,
humid weather is forecast.
See Appendix J,
Cereal Growth Stages, on page 136.
| 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* |
Do not apply at boot stage and beyond. |
| Comments |
Ground and aerial application. Apply only up to flag leaf
fully emerged stage (Zadoks 39). Do not apply at boot stage
(Zadoks 47) and beyond. Maximum 2 applications/yr. 12-hr re-entry
period. |
| Active ingredient |
propiconazole |
| Trade name |
Tilt 250 E |
| Rate per hectare (product) |
500 mL per ha |
| Rate per acre (product) |
200 mL per ac |
| PHI* |
45 |
| Comments |
Ground and aerial application. Apply at early signs of disease
from the beginning of stem elongation (Zadok's 29-37). If conditions
favourable to disease continue, apply a second spray before
the head is half emerged (Zadok's 49-55). Can be tank-mixed
with several cereal herbicides. Maximum 2 applications/yr. |
| Active ingredient |
propiconazole |
| Trade name |
Bumper 418 EC |
| Rate per hectare (product) |
300 mL per ha |
| Rate per acre (product) |
121 mL per ac |
| PHI* |
45 |
| Comments |
Ground and aerial application. Apply at early signs of disease
from the beginning of stem elongation (Zadok's 29-37). If conditions
favourable to disease continue, apply a second spray before
the head is half emerged (Zadok's 49-55). Can be tank-mixed
with several cereal herbicides. Maximum 2 applications/yr. |
| Active ingredient |
tebuconazole |
| Trade name |
Folicur 250 EW |
| Rate per hectare (product) |
500 mL per ha |
| Rate per acre (product) |
200 mL per ac |
| PHI* |
36 |
| Comments |
Ground and aerial application. Apply to leaf foliage at the
first sign or very early stage of disease, especially if weather
conditions are conducive to disease development, up to the
end of the flowering stage. The use of a non-ionic surfactant
(Agral 90 or Agsurf) is NOT required as it is built into the
formulation. Use a minimum of 100 L/ha of water for ground
application, 47 L/ha of water for aerial application. Maximum
1 appplication/yr. 12-hr re-entry period.
Before using Folicur for control of wheat leaf diseases,
consider that Folicur can only be applied once per year
and has been traditionally used for Fusarium control,
where applications are targeted at head emergence.
|
| Active ingredient |
tebuconazole |
| Trade name |
Folicur 432 F |
| Rate per hectare (product) |
292 mL per ha |
| Rate per acre (product) |
118 mL per ac |
| PHI* |
36 |
| Comments |
Ground and aerial application. Apply to leaf foliage at the
first sign or very early stage of disease, especially if weather
conditions are conducive to disease development, up to the
end of the flowering stage. Use the higher rate when weather
conditions are conducive to heavy disease development. Use
non-ionic surfactant such as Agral 90 or Agsurf at 0.125%
vol/vol. Use a minimum of 100 L/ha of water for ground application,
47 L/ha of water for aerial application. Maximum 1 application.yr.
12-hr re-entry period.
Before using Folicur for control of wheat leaf diseases,
consider that Folicur can only be applied once per year
and has been traditionally used for Fusarium control,
where applications are targeted at head emergence.
|
| 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* |
Do not apply at boot stage. |
| Comments |
Ground and aerial application. Do not apply the second application
within 14 days of the first. Apply only up to the flag leaf
fully emerged stage (Zadok's 39). Do not apply at boot stage
(Zadok's 47) and beyond. Can be tank-mixed with Buctril M
in wheat. Maximum 2 applications/yr. 12-hr re-entry period
|
| Active ingredient |
prothioconazole + tebuconazole |
| Trade name |
Prosaro 250 EC |
| Rate per hectare (product) |
800 mL per ha |
| Rate per acre (product) |
324 mL per ac |
| PHI* |
36 |
| Comments |
Ground and aerial application. Use a minimum of 100 L/ha
of water for ground application, 50 L/ha of water for aerial
application. Maximum 1 appplication/yr. 12-hr re-entry period.
|
Related links...
