Herbicides
189
• 
Safety - page 25 • First aid - page 33 • Resistance management - page 41
Crops, Rates and Staging
General non-selective weed control - annual and perennial grasses and broadleaf weed seedlings
Crop
Rate
Timing and specific comments
Non-crop areas
Initial Treatment
Sandy or sandy loam: 5.8 - 11 kg/acre
Clay or high organic soils: 16 - 22 kg/acre
Re-treatment: 2.0 kg/acre
Apply at any time, except when ground is
frozen, providing adequate moisture is received
by rainfall or artificial means. Best results are
obtained when applied shortly before weed
growth begins. Dense growth should be
removed.
Observe a minimum interval of 90 days between
the first application and re-treatment.
A maximum of 2 applications per season is
permitted to a maximum seasonal use rate of
6.6
kg/acre per year.
Spot treatment and
small areas
Initial Treatment: 0.11 kg per 100 m
2
or 4.5 kg/acre
Re-treatment: 0.165 kg per 100 m
2
Restricted uses (requires authorization by provincial permit)
Irrigation and
drainage ditches
Initial treatment: 0.11 kg per 100 m
2
or 4.5 kg/acre in
100 - 200
L solution/acre
Re-treatment: 0.165 kg per 100 m
2
Apply during the non-crop season and when
ditch is not in use.
Weed control in crop
Asparagus
(
established)
Light sandy soils or soils in low organic matter:
0.45 - 0.9
kg/acre
High clay soils or soils with high organic matter:
0.9 - 1.8
kg/acre
No earlier than 4 weeks before spear emergence
or later than early cutting.
Application Information
Diuron or Karmex XP may be applied with ground sprayer, backpack sprayer or watering can.
Water Volume
:
Use sufficient water (100 - 160 L per acre) to provide thorough and uniform coverage.
Application Tips
Non-crop Areas
:
Do not use on sand, loam sand or gravelly soils with less than 1% organic matter. Do not apply to
slopes as soil erosion may occur.
Irrigation and Drainage Ditches
:
To minimize movement of Karmex XP/Diuron with irrigation water and avoid
crop injury, it is essential that the herbicides be fixed in the treated soil by moisture. Apply before expected seasonal
rainfall, if possible when soil in the ditch is still moist. If rainfall has not totaled at least 10 cm following treatment
and before intended use of irrigation ditch, fill with water and allow to stand for 72 hours; drain off waste and
remaining water before using ditch.
How it Works
Diuron is readily absorbed through the root system and less readily absorbed through stem and foliage.
Expected Results
Susceptible plants become chlorotic soon after treatment and then die. Degree of control and duration of effect will
vary with the amount of chemical applied, soil type, rainfall and other conditions. Regrowth of plantain, thistle, or
wild carrot will indicate that retreatment is necessary. Poor control may be expected if inadequate rate or weeds too
old or insufficient rainfall.
Restrictions
Rainfall
:
Rainfall needed to activate the chemical, carrying it into the root zone.
Grazing
:
Do not graze the treated crops or cut for hay; sufficient data are not available to support such use.
Re-cropping
:
Do not replant treated areas to any crop within 2 years after last treatment as injury to subsequent
crops may result.
Environmental Precautions
Diuron is toxic to aquatic organisms. Do not apply directly to aquatic habitats, irrigation or drinking water supplies or
aquatic habitats by cleaning of equipment or disposal of wastes.
Karmex XP/Diurex 80 W (cont’d)