The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1894-10-18
NEW DISEASE OF PINEAPPLES,
Commissioner Marsden Gives a
Statement About II.
NJ any OF the Pines Brought Here From
Australia a re Found to Have the Dis
ease. They VIII Be Condemned.
OFFICE OF THE BUREAU or
AGRICULTURE AND FoREsTRYl


Nh. 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 ali per-
sons who intend TO import pine
apple plants from Australia, 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 all 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. III. Tryon 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 APP
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
young roots are discolored at the tips,
and collapse on pressure. In the
third stage, the root tips have turned
brown and are very soft. In the
of the woody roots are brown and
granular, very brittle, and soon die
and decay. The cause of the disease
is q fungus which Is parasitic within |
the root tissue. This colorless fungus |
consists essentially of an intricate net |
work of mycelium supporting conidia, |
composed OF two rounded elements |
having q 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 |
ton 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 |
through 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 |
beneficial, and in all cases +. 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
appearances 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
Enraafrv