The Hawaiian gazette. [volume] (Honolulu [Oahu, Hawaii]) 1865-1918, 1894-10-19
NEW DISEASE OF P|NEAPPLES,
Commissioner Marsden Gives a
Statement About It.
IL any of the Pines Brought Here From
ease. They VIII Be Condemned.
OFFICE OF THE BUREAU OF
AGRICULTURE AND FORESTRY

Mr.. EDITOR: | have received en-
account from Prof. Koebele, who
has lately visited Queensland, of a
disease that is killing the pineapple
plants in that country.
The disease is a fungus that pre-
vents the plant from fruiting, final
ly killing the plant.
Fungus diseases are the most
difficult to combat, and no remedy
has been found for the pest in
Queensland.
wish to give notice to all per-
sons who intend to import pine
apple plants from Australis, that
all such plants will be rigidly ex-
amined, and if any of the plants
are found to be affected, the whole
lot will be condemned and de-
stroyed. The introduction of
this disease among the pine
apple plantations on these ISL
ands would in ali probability
ruin the industry, and it would be
a wise plan for all pineapple grow
ers to refrain from importing pine
apple plants from Australia.
The following account taken from
the American Agriculturist clearly
sets forth the nature of the disease,
and the appearances by which it
may be detected.
A disease which prevents pineapples
from fruiting, and slowly kills the
plants, has appeared in Queensland,
Australia. 81. Tryen reports (R. 1881
that the dark green of the leaves is
changed to yellow and red, they wilt
and twist, grow slowly, and the sparse
fruit which sets soon turns yellow.
The plant lives for months on the
food stored in the stem, but finally
decays at the root and dies. In the
first stage the roots are normal in ap-
pearance, but the root hairs, instead
of being simple cylinders, now end
bluntly, are terminally twisted and
club-shaped. The expanded tips con-
tain granular matter. In the second
stage, the unwooded parts of the
y IOOlS arc ulSCOlOIcu dO IllO UPS
and collapse on pressure. In the
third stage, the root tips have turned
brown and are very soft. In the
fourth stage, all the young and many
of the woody roots are brown and
granular, very brittle, and soon die
and decay. The cause of the disease
is a fungus which is parasitic within
the root tissue. This c0lorless fungus
consists essentially of an intricate net
work of mycelium supporting conidia,
of two rounded elements
having double contour. The conidia
may be almost sessile upon the mycel-
ium, or may be supported on slender
pedicels of greater or less length.
They are readily detached, and are
generally found existing with the
mycelium isolated in the tissues and
vessels, either with two combined or
simple spores. The injurious opera
tion of the fungus is dependent upon |
the prevalence of favorable weather,
or upon the pineapple plants being |
grown on clay subsoils. The dis |
ease is probably not communicable |
the atmosphere by spores, |
but only by direct infection with the |
mycelium spawn. The character of |
the plants does not seem to influence |
the disease, nor previous or long crop
ping, nor the kind of fertilizer, nor
the method of cultivation. In the
case of clay subsoils, drainage will be
and in all cases e. NJ. Shell
ton advises the ploughing up of those
plots which are infected, and the
planting of other crops thereon for
several years.
Ifany plants now growing on these
islands should present any of the
described they should
at once be rooted up and burnt.
Any suspected plants sent to this
office will be examined without
charge.
J. MARsDEN.
Commissioner of Agriculture and