The Pest Management Regulatory Agency (PMRA) has published its re-evaluation decision regarding the active ingredient linuron, allowing future use of the herbicide with some risk mitigation measures.

Linuron can continue to be used on carrots, parsnips, potatoes, asparagus and shelterbelts. Herbicides containing linuron include Lorox and Afolan F. 

To protect human health from exposure, the following risk-reduction measures are required.  

Revised maximum application rates:

-  Limit pre-emergent and postemergent applications to carrots to a maximum annual application rate of 1.68 kg a.i./ha.

-  Limit pre-emergent and postemergent applications to parsnips to a maximum annual rate of 1.50 kg a.i./ha.

-  Limit pre-emergent application to potatoes to a maximum annual rate of 1.78 kg a.i/ha.

-  Limit pre-emergent or postemergent application to asparagus to a maximum annual application rate of 1.63 kg a.i./ha.

-  Limit dormant stage application to shelterbelts to a maximum annual application rate.of 2.16 kg a.i./ha. 

Cancelled uses include:  

-  Tree fruit (apple, peach, pear, plum/prune, cherry), corn (field and sweet), wheat, barley, oats, soybean, celery, Saskatoon berries, chokecherries, dill, coriander, caraway, sweet white lupins, and pre-emergent combined with postharvest application to asparagus. 

-  Airblast and right-of way application equipment. 

Source:  Pest Management Regulatory Agency March 29, 2021 news release