A dictionary of modern gardening - University Library

AMB 29 AMB
usually attains the size of a large hen's I
egg, has a rugged, ichorous, and even
mouldy surface, smelling strong and offensively.
The fibrous roots, besides
being generally thickened, are distorted
and monstrous from swellings, which
appear throughout their length, apparently
arising from an elTort of nature to
Another general result of experience
is, that the ambury is most frequently
observed in dry seasons. This is also
what might be anticipated, for insects
that inhabit the earth just beneath
its surfice, are always restricted and
checked in their movements by its
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abounding in moisture. Moreover, the
form receptacles for the sap, deprived plants actually affected by the ambury,
as it is of its natural spissation in the are more able to contend against the inleaves.
These swellings do not seem jury inflicted by the larva of tlie weevil,
to arise immediatp|y I'rom the attacks by the same copious supply.
of the weevil, for I have never observ- In wet seasons, I have, in a very few
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ed them containing its larva.
instances, known an infected cabbage
Mr. Marshall very correctly describes plant produce fresh healthy roots above
the form which this disease assumes the swelling of the ambury. Mr. Smith,
^^hen it attacks the turnip. It is a large gardener to M. Bell, Esq., of Woolsing-
excrescence appearing below the bulb, ton, in Northumberland, expresses his
growing to the size of both hands, and, conviction, after several years' expe-
as soon as the hard weather sets in, or rience, that charcoal-dust spread about
it is, by its own nature, brought to ma- half an inch deep upon the surface,
turity, becoming putrid and smelling and just mixed with it by the point of a
very offensively.
spade, effectually prevents the occur-
These distortions manifest themselves rence of this disease. That this would
very early in the turnip's growth, even be the case we might have surmised
before the rough leaf is much developed. from analogy, for charcoal-dust is offen-
Observation seems to have ascertained. sive to many insects, and is one of the
that if the bulbs have attained the size of most powerful preventives of piitrefaca
walnut unaffected, they do not subse- tion known. Soot, I have reason to
quently become diseased. The maggot believe, from a slight experience, is
found in the turnip ambury is the larva as effectual as charcoal-dust. Judging
ofa weevil called Curculiopleurostigma. from theoretical reasons, we might con-
" I have bred this species of weevil," elude that it would be more specifical
says Mr. Kirhy, " from the knob-like for, in addition to its being, like char-
palls on turnips called the ambury, and coal, finely divided carbon, it contains
I have little doubt that the same in- sulphur, to which insects also have an
sects, or a species allied to them, cause antipathy.
the clubbing of the roots of cabbages." I have a strong opinion that a slight
Marsham describes the parent as a dressing of the surface soil with a little
coleopterous
colour, with
insect of a dusky black of the dry hydro-sulphuret of lime, that
' the breast spotted with may now be obtained so readily from
white, and the length of the body one the gas-works, would prevent the oc-
currence of the disease by driving the
weevils from the soil. It would probably
as effectually banish the turnip fly or
flea, if sprinkled over the surface immediately
after the seed is sown, I
entertain this opinion of its efficacy io
preventing the occurrence of the ambury,
from an instance when it was applied
to some brocoli,ignorantly endeavoured
to be produced in successive
crops on the same plot. These had invariably
failed from the occurrence of
the amburv, but the brocoli was now
uninfected. The only cause for this
escape that I could trace was, that, just
previously to planting, a little of the
hydro-sulphuret of lime had been dug
in. This is a very fetid powerful com-
line and two-thirds. The general ex
perience of all the farmers and gardeners
with whom I have conversed upon
the subject, testifies that the ambury
of the turnip and cabbage usually attacks
these crops when grown for successive
years on the same soil. This
19 precisely what might be expected,
for where the parent insect always deposits
her eggs, some of these embryo
ravagers are to be expected. That they
never attack the plants upon a fresh
site is not asserted ; Mr. Marshall's
etatement is evidence to the contrary ;
but it is advanced that the obnoxious
weevil is most frequently to be observed
in soils where the turnip or cabbage has
recently and repeatedly been cultivated.
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