Pulse growers have another herbicide option for tackling grounsel and blackgrass in vining peas and spring beans this coming season.

An EAMU (Extension of Authorisation for Minor Use) has been granted for the use of Dual Gold (S-metolachlor) in vining and edible podded peas (for example, sugarsnap) and for use in spring beans.

It is a pre-emergence herbicide which is currently approved for use in forage and grain maize and has activity on several grasses, including blackgrass and broad-leaved weeds such as red deadnettle, mayweed, sow thistle, field speedwell and fat hen.

“There is also useful control of groundsel which can be a problem to control with some currently available products such as Nirvana (imazamox + pendimethalin) and straight pendimethalin formulations,” says Jim Scrimshaw, principal technical officer, Processors and Growers Research Organisation (PGRO).

The EAMU permits the pre-emergence use of Dual Gold at 1 litre/ha between 1 March and 31 May. Bearing in mind the limited spectrum of broad-leaved weeds controlled, an appropriate partner product will be required and PGRO is carrying out work in 2014 to help determine the efficacy of different tank mix options with Dual Gold.

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“We are seeing increasing incidences of blackgrass resistance, particularly to ALS and ACCase herbicides. However, Dual Gold has a different mode of action which should prove useful in this respect when used in conjunction with other chemical and cultural means of control,” he says.

There are no following crop restrictions and, from PGRO work carried out in 2013, spring beans currently on the Recommended List appear highly tolerant to the product.

As with all EAMUs, the efficacy and toxicity of the product for which it has been granted has not been assessed and, as such, the user bears the risk in respect of failures concerning efficacy or toxicity. Growers should be in possession of a copy of the EAMU before use which can be downloaded from the HSE web site via their Pesticides Register Database (www.pesticides.gov.uk).