Potato growers have more flexibility in when they use the potato desiccant Reglone (diquat) this season, following new recommendations from Syngenta.

The product can now be used at a low (1.0 litre/ha max) initial application rate where the result of the in-field Soil Moisture Assessment for Reglone Treatment (SMART) is a fail or borderline (i.e. dry soil).

Previously growers were advised to avoid using Reglone if the result was a fail (the soil around the tubers is too dry to be squeezed into a ball that retains its shape).

This initial low rate will be enough to trigger crop senescence, stop tuber bulking and initiate skin set, said the firm’s technical manager, Jon Ogborn. “Growers can safely follow up the initial application with up to 3.0 litres/ha of Reglone – five to seven days later – to complete the desiccation process.”

Where soil passes the SMART test, Syngenta advises using an initial dose of up to 2.0 litres/ha, depending on crop vigour, followed by a subsequent application, up to a total of 4 litres/ha per crop. Mr Ogborn estimates a typical split dose programme costs around £45/ha.