Growers are being advised against using diquat to desiccate cereal crops following a reduction in its maximum residue level (MRL) which came into effect on July 14.
Diquat MRLs for barley have been reduced to 0.02mg/kg by the EU.
Syngenta head of technical, David King, said: “While it is not illegal to use Reglone (diquat) on oats or barley there is a strong possibility that if people did use it they could have an MRL exceedance on barley. We have stopped promoting the use of Reglone for oats and barley.
“For Reglone, these MRL changes just affect barley but we also took the decision to remove promotion of the product for oats.”
Exceedance of MRLs by growers potentially affects marketability of products, said Mr King.
About 300 active ingredients across the industry are having their MRL’s reviewed by the EU in the next 3-4 years, he said.
Agrii Kent-based agronomist, Neil Harper, said he has rarely used diquat on pre-harvested barley. “It is only used as a last resort. If we have to spray off, we’re moving to using glyphosate a bit earlier and sticking to the right harvesting intervals. One field is down [in my area]. We’ll put glyphosate on with a 14-day gap from now until harvest.”