Herbicides
75
• 
Safety - page 25 • First aid - page 33 • Resistance management - page 41
Application Tips
Do not apply to crops underseeded to legumes. Apply Assert FL early post-emergence to the main flush of weeds.
Warm, moist conditions that promote active weed growth, small weed size, competitive crop and good growing
conditions after application will optimize the weed control. Weeds hardened off by cold weather or drought stress
may not be adequately controlled or suppressed, and regrowth may occur. For best results, ensure adequate spray
coverage of the target weeds. Only weeds that have emerged at time of application will be controlled. If the foliage
of the weed is wet at the time of application, control may be reduced.
Note
:
the additive effect of soil residues from
the use of Assert 300SC herbicide and Ally, Curtail M, Odyssey, Pursuit or Prestige herbicides on the same land has
not been determined.
How it Works
Assert is absorbed by foliage and roots and translocated to the growing points in the plants. Disrupts plant
metabolism causing growth to stop in susceptible plants. Frontline tank mix is readily absorbed by the weed foliage.
The florasulam inhibits the ALS enzyme in plants, resulting in a rapid halt in growth followed by yellowing and
reddening of the foliage, followed by death of susceptible weeds. The MCPA portions of Frontline mimic the
naturally occurring plant hormones and control the weeds by disrupting normal plant growth patterns.
Expected Results
Wild oats:
Stop growing within 24 - 48 hours. Yellow striping and purplish discolouration of the leaf may occur.
Leaves begin to die in 3 - 10 days, starting with the youngest and moving to the older leaves. Death of the plant may
occur in 1 - 3 weeks. Symptoms may occur more slowly at lower temperatures and high rainfall.
Broadleaf weeds:
Weeds susceptible to the Frontline tank mix will stop growing almost immediately.
The weeds turn yellow or reddish. Symptoms such as yellowing and red colouration may not be noticeable for
1 - 2
weeks. Some twisting may also be observed on weeds. Warm, moist conditions, small weed size and
competitive crop will optimize weed control provided.
Restrictions
Effect of Rainfall
:
Heavy rainfall immediately after application may wash the chemical off the foliage, and a
repeat treatment may be required. Do not apply if rainfall is forecast for the time of application.
Grazing
:
Do not graze treated fields or cut treated forage for silage or hay; sufficient data are not available to
support such use. (Barley, wheat grain or straw from fields treated with Assert FL can be fed to livestock.)
Re-cropping
:
Rotation to the following crops can be made.
One-year after application:
Black and Grey Wooded soil zones:
spring wheat, durum wheat, barley, sunflower, canola, flax, peas.
Brown and Dark Brown soil zones:
spring wheat, durum wheat, barley, sunflower, and CLEARFIELD canola.
Two years after the application, following crops can be grown in all soil zones: spring wheat, durum wheat, barley,
sunflower, peas, canola, flax, oats, canary grass. Conduct a field bioassay before planting lentils and sugar beets.
Environmental Precautions
Avoid application of Assert FL within 15 metres of water bodies (lake, pond, slough, streams, rivers).
Toxicity
Low acute mammalian toxicity. Acute oral LD
50
(
rats) = 3,078 mg/kg. Non-toxic to fish, birds, and bees.
Frontline A: has extremely low acute toxicity. Acute LD
50
= >6,000 mg/kg. Frontline B: has moderate acute toxicity.
Acute LD
50
of technical = 700 - 800 mg/kg.
Storage
Store between 0° - 35° C. Do not freeze. Shake well before using.
Assert FL (cont’d)