Clearfield Cereals - Risk of MRLs


Since its inception in the late 1990’s, Clearfield® technology has enabled growers  to control a range of grasses and broadleaves that were previously only managed through crop rotation, in barley, canola and wheat.

Intervix (imazapyr + imazamox), was originally the only chemical registered for use in Clearfield® technology, however it now resides on the shelf amongst other Clearfield® chemicals. A common ‘alternative’ has been the use of a home brew, that at the time was considered a cheaper, ‘alternative’ (imazapic + imazapyr); however, it should be noted that by no means is this an Intervix equivalent.

While utilising imazapic in the place of imazamox may seem harmless, imazapic is an entirely different chemical and most importantly, is not legally registered for use in barley/wheat. It is important to remember that registration of a chemical in a crop deems the product safe if used in a manner dictated by the label. Consequently, because imazapic is not registered for use in-crop in barley/wheat, no maximum residue limit (MRL) is set for it in certain countries.

If an unregistered chemical, (such as imazapic) is detected in a shipment of export malt barley, the MRL defaults to 0 mg/kg and automatic rejection occurs. One shipment rejection can quickly lead to market closure, undermine market access and tarnish the name of Australia’s agricultural products both immediately and in the future.

This year, one grain accumulator has reported that 21 of 24 receival sites in Northern Victoria have Clearfield® barley exceeding the MRL. The reckless activity of applying home brews to Clearfield® malting barley destined for export, will this season lead to all deliveries being tested. If a load is found to be exceeding the stated MRL; it will result in the grower fined, legal action pursued and liability for the grain stack affected. 

It is therefore imperative to practice good stewardship by double checking the chemicals you use, follow all directions on the label and consult your agronomist if you have queries or concerns.