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Safety - page 25 • First aid - page 33 • Resistance management - page 41
Herbicides
Crop
Timing
Summerfallow
Apply for control of labelled weeds.
Fall stubble applications
Apply in the fall to control annual broadleaf weeds and grasses prior to spring seeding of wheat
(
including durum), barley and oats.
Weeds, Rates and Staging
Rate: PrePass XC A: 40 ml/acre. PrePass XC B: 375 m/L/acre.
Grasses controlled at 2 - 4 leaf stage
downy brome
giant foxtail
green foxtail
Persian darnel
volunteer barley
volunteer wheat
wild oats
Broadleaf weeds controlled at 2 - 4 leaf stage
annual sow-thistle*
Canada fleabane**
cleavers
common chickweed
common ragweed**
dandelion: seedlings and overwintered
rosettes, mature plant up to 30 cm
flixweed
hemp nettle
kochia
lady’s-thumb
lamb’s-quarters
narrow-leaved hawk’s beard**
perennial sow-thistle*
redroot pigweed
Russian thistle
scentless chamomile
shepherd’s purse
smartweed
stinkweed
volunteer canola, including Roundup Ready
and CLEARFIELD
volunteer flax
wild buckwheat (1 - 5 leaf)
wild mustard
*
Suppression with PrePass
**
Up to 8 cm in height
Application Information:
With
:
Apply with ground equipment only. Do not apply by air.
Water volume
: 20 - 40
L/acre.
Application Tips
Pre-seed weed burndown/summerfallow: PrePass must be applied to emerged, actively growing weeds. Warm, moist
growing conditions promote active weed growth and enhance the activity of PrePass by allowing maximum foliar
uptake and contact activity. Weeds hardened off by cold weather or drought stress may not be adequately controlled
or suppressed and re-growth may occur. For best results, ensure thorough spray coverage of target weeds. Reduced
control may also occur when applied to weeds heavily covered in dust.
Fall stubble
:
Prepass can be applied until late October, but active weed growth must be present.
How it Works
PrePass A is taken up by leaves and stops growth of susceptible weeds rapidly via inhibition of the ALS enzyme.
PrePass B is a non-selective systemic herbicide that moves through foliage into the roots, resulting in plant mortality.
Expected Results
Weeds susceptible to PrePass A will stop growing almost immediately. Newer leaves start to yellow and wilt,
followed by a loss of green colour. Symptoms will spread to the rest of the plant with some weeds showing purpling
or reddening. Under good growing conditions, complete control may occur within 7 - 10 days after application.
Annual weeds susceptible to PrePass B will wilt and yellow within 2 - 4 days. Perennials will show similar
symptoms within 5 - 10 days after application.
Restrictions
Rainfall
:
Heavy rainfall immediately after application may wash the chemical off the foliage, reducing effectiveness.
Do not apply if rainfall is imminent at time of application.
Grazing
:
Do not graze treated areas within 7 days of application.
Re-cropping
:
Pre-seed burn-down application - Fields treated with PrePass herbicide tank mix can be seeded to
barley, oats or wheat in the year of application.
Summerfallow application
:
Fields treated with PrePass herbicide tank mix can be seeded to barley, canola, durum
wheat, peas, wheat the following spring. Canola and Peas can be grown if fallow application occurred prior to
August 1 in the fallow year.
PrePass XC (cont’d)