Herbicides
67
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Safety - page 25 • First aid - page 33 • Resistance management - page 41
Weeds, Rates and Staging
Prior to seeding
:
Dandelion and annual weeds - apply 1.7 L/acre to actively growing weeds less than 10 cm tall.
Do not cultivate for 10 - 14 days.
Post-harvest
:
Canada thistle, perennial sow-thistle - apply when thistles have 10 - 15 cm of new growth. Do not
cultivate for 2 weeks after application. Do not replant any crops in the treated areas except soybean, corn, white bean,
wheat, barley, canola, and field peas.
Apple orchards
:
Annual weeds, Canada thistle, dandelions, field horsetail, hoary cress, poison ivy, poison oak,
perennial sow-thistle, quackgrass (suppression).
Shelterbelts
:
Annual weeds, Canada thistle, dandelions, poison ivy, poison oak, perennial sow-thistle, quackgrass
(
suppression).
Pasture and non-cropland (roadsides, fencerows, ditch banks)
:
Weeds
Rate
Application directions
Canada thistle,
perennial sow-thistle
5.0 - 11.3
L/acre Apply when most thistles are in the early bud to bloom stage. Do not cultivate for
3
weeks. Do not till infested areas during the fall or spring before treatments
cattails
15 - 18.5
L/acre Apply after catkins are fully formed and up to frost. Do not disturb sprayed plant.
Do not apply where water will be used for irrigating, drinking or other domestic uses.
Do not apply where water is not wholly confined to users property.
dandelions
1.7 - 5.0
L/acre
Treat when dandelions are young and actively growing. Tillage can occur 3 weeks after
treatment but is not necessary.
field horsetail
5 - 6.6
L/acre
Spray when horsetail is growing vigorously. Usually when 10-15 cm in height.
hoary cress
7.5 - 11.0
L/acre Spray during advanced rosette and bud stages. Treated area should not be mowed. If
necessary re-treat with one half the original rate when re-sprouts are 10 to 15 cm tall.
leafy spurge
15 - 18.5
L/acre Spray between the advanced flowering and early seed development stage. Treated
areas should not be mowed but may be plowed after top growth is bleached. Spot
treat regrowth the following year.
milkweed
7.5 - 11.0
L/acre Treat in early summer when a majority of shoots have emerged. Spot treat any
regrowth the following year.
poison ivy,
poison oaks
3.7
L/acre
Apply in 200 to 400 litres of water per acre as an overall spray or as a spot treatment.
Apply anytime after foliage is fully developed in spring until plant begins to turn colour
in the fall. Spray thoroughly, wet leaves, stems and suckers to ground line.
quackgrass
5.0 - 11.3
L/acre Apply when quackgrass is 10 - 15 cm tall. For best results, cultivate 3 weeks
after treatment.
toadflax
7.5 - 11.0
L/acre Treat during advanced rosette to prebud stage. Till 3 weeks after treatment, when top
growth is bleached. Spot treat any regrowth the following year.
Application Information
How to Apply
:
Ground applications only.
Do not apply by air.
Water Volume
:
Non-crop areas:
40 - 120
L/acre,
Crop areas:
20 - 80
L/acre,
Shelterbelts:
40 - 120
L/acre.
Application tips
Avoid using rates greater than 8 L/acre during preplant application on light soils with low organic matter. Spray to
point of runoff, complete coverage of weeds essential. For good control, complete coverage of weeds is essential.
Under or around desirable plants or trees, avoid contact with foliage, green stems or fruit as severe injury or
destruction may result. Use a hooded sprayer if necessary. Do not disturb or mow treated plants for 3 weeks after
treatment. If no tillage is possible, then spot treat weed regrowth or respray at 1/2 original rate. Do not contaminate
any body of water. Do not apply where water will be used for irrigating, drinking or other domestic use. Do not spray
near sparks or open flame For best results, apply Amitrol 240 in the early morning or evening when the humidity is
higher. Avoid application when daytime temperatures exceed 25°C or when air conditions are very dry.
How it Works
Systemic herbicide that inhibits chlorophyll production. Moves through foliar and root system.
Amitrol 240 (cont’d)