Potato seed treatment Monceren is being withdrawn immediately after UK regulators announced an end to the use of the active pencycuron, which was used to control rhizoctonia.

According to Farmers Weekly, the UK Chemicals Regulation Directorate (CRD) announced an end to the use of Monceren, manufactured by Bayer, as of 25 March 2020, and growers are advised to look at alternatives.

The product is a dry powder formulation applied to seed tubers at planting to control Rhizoctonia solani, a pathogen that causes symptoms such as tuber black scurf and stem canker.

An EU proposal to cut the maximum residue limit (MRL) for pencycuron earlier in March meant it was still possible that it could be applied to seed planted this spring, but now, the CRD’s announcement means it is no longer possible to apply Monceren for any purpose. Bayer has already advised all users to consider an alternative treatment, such as its own product Emesto Prime (penflufen).