Update on Mancozeb Re-Evaluations

On November 19, 2020, the Pest Management Regulatory Agency (PMRA) released the long-anticipated final re-evaluation decision for mancozeb products (ie., Manzate Pro-Stick, Penncozeb 75 Raincoat, Dithane Rainshield). For the full report, see RVD2020-12, Mancozeb and Its Associated End-use Products.

The new risk-reduction measures come into effect November 19, 2022 and include:

New rate
4.5 kg a.i. / ha
Minimum interval between applications
7 days
Maximum applications per year
Restricted entry interval
12 hours – general re-entry 35 days – hand thinning
Preharvest interval
77 days

Growers may notice updated labels on new product purchases over the next year as registrants make the required amendments. For instance, the updated Manzate Pro-Stick label is now available on the PMRA label search. While PMRA encourages growers to follow updated labels immediately, the previously approved labels are valid until November 2022. Growers will be responsible for acquiring the previously approved label for documentation. This can be provided by emailing PMRA at hc.pmra.info-arla.sc@canada.ca. In your email, be sure to include the product name and registration number of the label you are requesting.

In the last Orchard Network Newsletter article on the recent re-evaluation decisions, Considerations for the Future of Apple Scab Management (April 2021), I mentioned it was still a moving target for how half rates would be accounted for. This is beginning to become more clear (though not ideal for apple growers) after the release of the updated Manzate Pro-Stick label. While the label does state “Do not apply more than 24 kg/ha/year (18 kg a.i./ha/year)”, it also includes “Do not make more than 4 applications/ha/year”. This means regardless of whether the application was a full or half rate, growers in Canada will be legally restricted to a maximum of 4 applications per year.

The updated Dithane Rainshield and Penncozeb 75 Raincoat labels have not been released as of writing this article.

Kristy Grigg-McGuffin
Kristy Grigg-McGuffin

Horticulture IPM Specialist, OMAFRA