| Bracken
is now a menace, because over the last century it has hugely
increased its coverage of heather and pasture, and because it
continues its increase exponentially. A hundred years ago, many
villagers were pig owners or small scale stockmen, who cut bracken
for animal bedding, and for whom access to choice bracken beds
was competetive. The areas nearest to the villages may well
have been cut twice (annually), and it is thought that this
cutting once kept it under control. Other reasons for its most
recent spreading could be the ability of the plant to fix nitrogen
from a polluted atmosphere, or its use of higher fertility levels
(from larger sheep flocks).
All
manner of mechanical means have been tried to tame it during
the last 50 years, and yet there still remain areas of disagreement.
Some scientists advocate crushing the fronds in late July,
others advocate 2 cuts each year, while still others, suggest
only one late cut. The truth is that large, long-term experiments
with machinery are rare, and that most land-owners use the
chemical Asulox to control it. This practice seems likely
to continue, despite the expense, and despite the lack of
research into many aspects of chemicals short/long term effects
(see report of E.P.A.). Of course, bracken itself contains
noxious chemicals, and releases carcinogenic spores in August,
which means that destroying it by hand or mechanical means,
is not always a safe option, and that masks are worth wearing.
On
our sheep-stray area of moorland, bracken has been contained
by the use of Azulox (in the past). Our current non-chemical
strategy mainly involves blade-strimming in late June/July,
and repeated hand chiselling in isolated beds. Deep chisel
hoeing and hoiking, is much more damaging than cutting (and
decreases the shoot numbers), but it needs determined labour
& lots of time. Chiselling in long heather can be awkward,
so we sometimes resort to pulling the young ferns by hand.
Generally
speaking, mechanical mowing or crushing is slow and difficult,
and in some awkward areas of terrain, even small-scale crushers
are limited to where they can go. The effect of this mechanical
work is mostly to contain the problem. If it is relentless,
then less foliage is produced, and spreading can be controlled.
If the foliage of any rhisome plants is damaged often enough,
energy levels are weakened, so that repeated attacks in the
same season must be more damaging than a single one, in late
July. With bracken, this is an opinion that is well supported
by other peoples research.
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