The key potato desiccant spray, diquat, has been granted a derogation for use in Ireland this autumn.

Diquat is mainly used to destroy tops and induce skin-set in potato crops, but lost authorisation in the EU in February 2020. A derogation for its use was granted in autumn of 2020.

It has been confirmed that the Minister for Agriculture has approved a derogation application for the use of diquat on potatoes as of Monday 6 September 2021.

The details emerged in a recent IFA note to growers.


The derogation was granted to allow for the completion of the transition away from diquat and to enable growers to trial alternative desiccation methods.

The derogation allows diquat to be used at a reduced maximum rate of 0.75l/ha and is to be applied in one single application. Growers should also note the new PCS numbers with this year’s products (Reglone, PCS 06845).

All safety precautions for users and bystanders must be used which includes wearing full personal protection equipment (PPE) and using low drift nozzles.

Welcome announcement

While many will welcome this announcement, growers should be aware that this derogation applies for this year only, the IFA has warned.

Gorwers should use diquat with alternative chemistry (Spotlight Plus and Gozai) and/or haulm topping to establish which system works best for their situation.

This will allow growers to plan their desiccation strategies for 2022 and beyond.