Rhizoctonia control is set to become much more difficult for potato growers with news of a second seed treatment being withdrawn, just weeks after the loss of Monceren.

EU regulators have recommended the withdrawal of penflufen, a fungicide contained in the powder seed tuber treatment product Emesto Prime DS.

See also: Monceren potato seed treatment to be withdrawn immediately

It is used to control Rhizoctonia solani, which causes stem and stolon canker and black scurf in potatoes.

The revocation – which has yet to be formally adopted by the EU Commission – follows work carried out by regulatory authorities in Poland, the rapporteur state for penflufen’s recent reassessment.

Outcomes led to the active ingredient’s “reclassification” and consequently Bayer Crop Science’s marketing authorisation for penflufen-containing products is set to be withdrawn.

The anticipated revocation will not affect the marketability of crops treated this season.

The news comes just weeks after Monceren (pencycuron), another powder seed treatment formulation also used for rhizoctonia control, was lost.

One option left

Once any grace period ends, it will leave potato growers with just one on-planter powder seed treatment option in RhiNo DS (flutolanil).

In a statement to Farmers Weekly, Julian Little, Bayer’s head of communications and public affairs for the UK, expressed his sympathy for growers concerned about control of the disease.

“Emesto Prime DS has set the standard in black scurf control since it was introduced in 2018 and we are hopeful that the UK authorities will permit its use for another season to enable growers to make a managed transition to an alternative means of protection,” he said.

“Once we have received end-of-sales and use-up dates from the regulator, we will communicate these to the industry.”