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Safety - page 25 • First aid - page 33 • Resistance management - page 41
Herbicides
under hot and humid conditions, some crop injury and delay in maturity may result. Spraying in the evening and/or
increased volumes of water (40 or more litres per acre) may reduce the risk of flax injury.
How it Works
A systemic, absorbed by leaf and stem surfaces and translocated to the actively growing regions. MCPA disrupts cell
division, causing abnormal growth response, thereby affecting respiration and food reserves.
Expected Results
Weeds start to twist between 2 - 20 days after spraying, depending on weather conditions, formulation and nature
of weeds. Following the twisting and bending, plants will turn brown, and then die. Only emerged weeds will be
controlled.
Restrictions
Effect of Rainfall:
Rain within 6 hrs of MCPA Na salt, or MCPA K-salt, 4 hrs of MCPA amine, and 2 hrs of MCPA
ester application will decrease weed control.
Grazing:
Do not graze or cut for green feed until 7 days after spraying.
Re-cropping:
No restrictions the year after application.
Environmental Precautions
MCPA is toxic to aquatic organisms and non-target terrestrial plants.
Leaching:
MCPA can readily leach from soil, resulting in contamination of groundwater particularly in areas where
soils are permeable (e.g. sand, loamy sand and sand loam soils) and/or the depth to the water table is shallow.
Toxicity
Moderate acute mammalian toxicity. May cause burning upon contact with skin and eyes, and it can be absorbed
through the skin.
Storage
If frozen, warm to 5°C and mix well before using.
Mecoprop
Group 4
Formulation
Product
Company
Active ingredient
Formulation
Container size
Mecoprop - P (PCP# 27891)
Loveland Products Canada
Mecoprop: 150 g/L
Liquid
10
L
Crops and Staging
Crop
Staging
Remarks
Barley, oats and wheat
3-
leaf expanded stage until the early flag
leaf (shot-blade)
Apply under good growing conditions. Do not spray on
grain underseeded with legumes.
Weeds and Staging
In barley, oats and wheat
Rate
:
small weeds (seedlings) - 2.2 L/acre. Mature weeds: 3.4 L/acre.
Apply to weeds from 2 - 4 leaf stage
black medick
Canada thistle (top growth only)
chickweed
cleavers
corn spurry
lamb’s quarters
plantain
plantain
volunteer clover
wild mustard
MCPA (cont’d)