Bracken Control Group

Lowna Research

The Lowna trials took place during the period 2021- 2024 at Lowna on the North York Moors to further investigate efficacy of bracken treatment, non-target species effects and comparisons of herbicides in 5 different trial groups.

A report can be found on each trial grouping:

• Aerial Application
• Relative safety of control efficacy of ground (hand-boom) comparisons of applied actives
• Ground-based trials with adjuvants
• Ground-based canopy penetration of Asulox
• Ground-based trials, efficacy and comparisons.

A range of different herbicides (active ingredient) were tested including Asulox (asulam), Squire Ultra (amidosulfuron), Genoxone (triclopyr / 2,4-D) and the adjuvant / drift retardant Validate. In some cases, these trials were the first of their kind: e.g. assessing the efficacy of Squire Ultra aerially and the use of Genoxone as a systemic herbicide, which was trialled for the first time in bracken control.

When applied aerially, Asulox (either with an adjuvant or without)  exhibited excellent levels of control with a positive impact on non-target species. Squire Ultra was not effective and had a very poor level of control. Ground-based application also saw Asulox ranked first, followed by Genoxone and again, Squire Ultra was the worst performer over the 3 year evaluation. 

In one trial, a higher volume, lower concentration of Asulox, was applied and compared to a lower volume, higher concentration application. Unexpectedly, an analysis of the efficacy and impact on NTS showed a significant difference in favour of the higher volume treatment.

In another trial, Asulox, at half the maximum label rate, and Squire Ultra were applied with a range of adjuvants as a mix. For Asulox, this improved the level of control on the bracken and reduced the impact on non-target species, especially when paired with Validate. This combination also appears to have resulted in an accelerated litter degeneration, which has the positive effect of providing better re-colonisation conditions for NTS and reducing the amount of litter available to support the Sheep Tick Ixodes ricinus life cycle.  In this trial, Squire Ultra once again proved to be a poor performer and was not considered to be viable for use in extensive bracken control treatment.

Genoxone is currently the only formulated and approved product that might have potential for bracken control and here, its ability to be effective in application has been confirmed but further research is needed.

For more information, see Bracken Briefing No.33, and the reports from each group of trials below.

Final Reports