Enhanced grass-weed control seen in forage maize

With encouraging results already seen in replicated field trials, Agrii agronomist Todd Jex set up a tramline trial to assess the weed control benefits of adjuvant Sorrento in a continuous maize crop in Dorset.

The Fraser family have built up their farming enterprise (A & R Fraser) near Shaftesbury in Dorset to over 1200ha in recent years, with contract farming forming a large percentage of the business alongside their beef and arable mixed farm.

George Fraser doesn’t grow forage maize on his own farm but is responsible for maize ground preparation and spraying operations under the business’ contact farming agreements. It was on one of these that a tramline trial was set up to assess weed control with and without the addition of Interagro’s adjuvant, Sorrento, with the help of Agrii agronomist Todd Jex.

“The weed profile in the field was mostly broadleaf weeds, including black bindweed and field speedwell, with annual meadow grass, wild oats and barnyard grass also present,” explains Todd.

The trial was set up to include an area of the field where barnyard grass was most prolific. A pre-em was applied and followed by 0.75l/ha Samson Extra plus 0.5 l/ha Callisto at around the six-leaf stage of the maize crop. Sorrento was added to the tank at a 0.1% inclusion rate in the treated tramline.

“There was very little difference to be seen on the broadleaf weeds where Sorrento was or wasn’t added to the mix. What was noticeable was an increased speed of effect on the barnyard grass. At four weeks post-application this difference was significant.”

George notes that the barnyard grass was the worst he’d seen it in the continuous maize field last year, so the additional level of control achieved with the Sorrento was very valuable.


Significant improvement in control with inclusion of Sorrento

Barnyard grass control with and without Sorrento

Significant reduction in Barnyard grass from inclusion of Sorrento

Samson Extra + Callisto + Sorrento

High barnyard grass population without Sorrento

Samson Extra + Callisto

Source: Todd Jex

From one trial in one season, what was Todd able to conclude from the results? “I believe the adjuvant could be useful where difficult to control grassweeds are present, particularly barnyard and bristle grasses. In this trial there were no real effects on the broadleaf weeds present,” he says.

The trial has led Todd to wonder whether Sorrento could be useful to help control grassweeds suck as brome in the spring when using Broadway Star (pyroxsulam+ florasulam).

Previous work carried out by Interagro and Agrii have found Sorrento enhances the speed of kill of other grassweeds, such as ryegrass and wild oats when used in tank-mix with Axial Pro (pinoxaden) and also work well with ALS-chemistry, with positive outcomes in 51 of 52 replicated field trials.