Bracken control in the first year is as good as it gets!

Bracken (Pteridium aquilinum (L.) Kuhn) can be problematic for various land-based sectors such as agriculture, forestry, recreation, shooting, as well as for catchment water quality. It can also have detrimental impacts on conservation sites, reducing biodiversity. The herbicide asulam has been shown to be an effective control method but herbicide use might be limited on some conservation sites. Various mechanical control methods are available, though some still require empirical evidence to assess their efficacy. A longterm field experiment was established in 2011 near Cirencester, Gloucestershire using a completely-randomised design, with 5 m × 5 m treatment plots replicated three times. The site had been routinely cut once yearly prior to the experiment to reduce bracken dominance. Three bracken management methods, deemed appropriate for small conservation sites with access issues, were considered: cutting once yearly; cutting twice yearly; and, hand pulling once yearly, each being compared to an untreated control. Frond heights and densities were used to assess plant performance and hence the efficacy of control treatments. In comparison to the control plots that received no management intervention, all three of the mechanical control methods were found to significantly reduce frond heights and densities, each by about half. Cutting twice yearly was more effective in reducing frond height than cutting once, with hand pulling being the least effective. All three performed equally well in reducing frond density, but none demonstrated a significant longer-term (6 years) reduction in plant performance. Hand pulling required considerable time and effort delivering the least favourable outcomes, whilst cutting twice was only marginally better than cutting once. It was therefore recommended that a single annual bracken cut would give the best cost benefit for small conservation sites, enabling acceptable levels of control, but not complete eradication