Potatoes in Canada

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Mancozeb fungicide use only permitted for potatoes

The Pest Management Regulatory Agency (PMRA) completed its re-evaluation of mancozeb and found the continued registration of products containing mancozeb acceptable for foliar application to potatoes in Canada.

June 25, 2018
By Potatoes in Canada


According to PMRA, all other uses of mancozeb are being cancelled due to unacceptable risks to human health and will be removed from the labels.

After an evaluation of available scientific information, PMRA found that foliar application of mancozeb to potatoes meets current standards for protection of human health and the environment. However, mancozeb met these standards when used according to the conditions of registration. Within this re-evaluation, PMRA made amendments to label directions.

The following lists of required measures have been sourced from PMRA’s re-evaluation of mancozeb decision document.

In order to protect the general population, PMRA requires the following measures:

  • Cancel all Canadian uses of mancozeb with the exception of foliar application on potatoes.
  • Permit a maximum of 10 applications per year on potatoes at a maximum application rate of 1.69 kg a.i./ha with seven-day application intervals and a one-day pre-harvest interval using aerial or ground spray only.

To protect the environment, PMRA requires the following risk-reduction measures:

  • Spray buffer zones to protect non-target habitats from pesticide spray drift.
  • Limiting aerial application to once per season.
  • Standard runoff reduction statement on product labels.
  • Hazard statements on product labels warning of the potential to contaminate groundwater through leaching.
  • Warnings on product labels regarding toxicity of mancozeb to aquatic organisms; birds; small, wild mammals; and certain beneficial insects.

In order to protect mixer, loader and applicators, PMRA requires the following measures:

  • Engineering controls: Closed mixing and loading for wettable powder products (water soluble packaging). Closed-cab groundboom tractor or respirator for custom applicators applying dry flowable formulations.
  • Personal protective equipment (PPE): Respirator when mixing/loading dry flowable products.

To reduce potential exposure to ethylene thiourea (ETU) from use of multiple ethylene bisdithiocarbamate (EBDC) pesticides, PMRA requires the following measures:

  • Limit applications of both mancozeb and metiram on potatoes during the same growing season.
  • Mancozeb does not present unacceptable risk to human health when used according to the revised conditions of registration, which include additional mitigation measures and label amendments.

Mancozeb is a broad spectrum contact fungicide used on a wide variety of food and feed crops. PMRA has a list of all currently registered products containing mancozeb in an attached appendix.

PMRA regularly re-evaluates registered pesticides to ensure they continue to meeting current health and environmental safety standards. PMRA considers data and information from pesticide manufacturers, published scientific reports and other regulatory agencies.

To read more, PMRA has published a summary of the decision online