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Mancozeb remains registered for foliar applications

The Pest Management Regulatory Agency (PMRA) has returned its decision for the re-evaluation of mancozeb. Under the authority of the Pest Control Products Act, the PMRA has determined that continued registration of products containing mancozeb is acceptable, with some exceptions and additional risk mitigation measures.

Supported uses of mancozeb products, including ground and aerial foliar application to potatoes, meet current standards for human health and environment protection, and have value when used according to the revised conditions of registration.

Use of mancozeb as a potato seed piece treatment has been cancelled due to lack of support from the manufacturers.

Mancozeb belongs to the group of fungicides commonly known as ethylene bis (dithiocarbamates) (EBDCs). These EBDCs decompose to ethylene thiourea (ETU), which has been classified as a probable human carcinogen by the U.S. Environmental Protection Agency (EPA). There are also concerns that ETU causes birth defects and genetic mutations.

The proposed final re-evaluation decision for mancozeb was published on Oct. 5, 2018, which suggested cancelling all uses of mancozeb – except on tobacco – due to unacceptable risks to human health and the environment. This proposed decision removed the original exception from PMRA’s June 2018 re-evaluation that allowed for foliar application of mancozeb on potatoes.

Keeping aerial applications of mancozeb is particularly good news for Prairie potato growers, as producers often use aerial applications for fungicides because of the nature of the landscape and the lower population.

For the full decision breakdown and list of additional mitigation measures, visit the PMRA website.