The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1904-04-04
JARED SMITH ON PLANT
DISEASES IN HAWAII
United States Experiment Station at Work on
Two Pests for Which Remedies Have
Already Been Discovered.

! This fungus disease can readily be
! kept in check:
l. By selecting for seed, cane that is
| perfectly sound and healthy;
2. BY carefully gathering up and
burning the stalks left on infected fields
after the cane has been harvested
| AS before stated this fungus usually
! proves serious only to young plant cane
or to older cane, the growth of which
has first been checked by attacks of
!; injurious insects, in which case infection
of the cane with the fungus occurs
through the wounds made by the insects
Whenever young plant cane looks yell
low and sIckly, or when seed cane fails
to terminate. or when growing cane
shows retarded growth and has its
leaves and stalks streaked with red
patches, or when dead cane either stand
ing in the fields or that which is left
on the field after the crop has been
harvested appears light and spongy- and
is covered with small pustu1es or bis
, tiers, the patches of cane exhibiting any
or all of these symptoms should be look
ed on with suspicion. Under no cir
cumstances, should seed cane be taken
from such fields.
THE .BROWN-EYED DISEASE OF
COFFEE
A fungus disease of coffee, causing
spotting of the leaves and injury to the
berry, is widely prevalent, although
rarely destructive, in the Hawaiian
coffee plantations. This fungus has
been identified by Mrs F. w. Patter-
son, Mycologist of the U. S. Depart
ment of Agriculture at Washington, D.
C., as Cercospora coffeicola B. & c. Its
presence In Hawaii was noted as early
as 1896 or 1897 by Prof A. Koebele, the
well known entpnlologist In January,
1899, Prof. Koebele reported this fun
gus as causing some losses in Puma and
Olaa. He says: In the wet or cooler
parts of Puma and Olaa the disease
seems TO spread. As yet it is only se-
rious to weak trees or nursery plants
where exposed, but is hardly noticeable
on healthy and vigorous trees" Its
presence on coffee trees has been noted
during the past three years in all the
coffee districts which the writer has visit
ed. As Professor Koebele points out in
his letter in which he first drew the
attention of our Department to the oc-
curence of this fungus disease in Ha-
waii, it is most prevalent on weak trees,
such as those in neglected and uneared
for plantations, or on isolated trees
growing in unfavorable localities, such
as door-yards, washed ridges, barren
hillsides and rocky, shallow Soils
The Brown-eyed disease has been re-
ported from Jamaica, Guatemala, Gaude-
loupe and from Brazil, in the latter coun-
try being widely distributed through all
of the cofee-growing provinces. Noack,
who has studied the life history of this
fungus in Brazil, describes it as follows
The disease produced by this fungus is
called the Brown-eyed disease on ac-
count of the brown spots formed on the
leaves. As rule these are round or
oval, on the lower surface clear brown,
on the upper surface dark brown. In
the center the spots are Tighter and
grayish.. The margin is sharply defined
on the upper surface, dark brown or red
dish, generally slightly raised, the sur
face often marked by fine concentric
strlae Frequently several spots unite
The nerves of the leaves do not prevent
their spreading. The average diameter
of the spots at the center of the leaf is
one-hfth of an inch. The ia. gest are
about one-third of an inch If a leaf is
badly affected 1t appears more or less
brown. The formation of the. spots be-
gins on the upper surface of the leaves.
The spots are at first without a sharp
marginal line and are scarcely visible on
the under surface. / he fungus not only
occurs on the leaves but on the half
formed cherry. On these, little dark
spots appear, which multiply ard spread
until finally about half the cherry be-
comes brown and dried
Many of the cherries which are in
fected with this disease drop off Those
which remain on the tree do not ripen
we'll and the beans become black, besides
being incompletely developed. Even in
milder attacks where the above serious
condition does not prevail and the bean
remains uninjured great difficulty is met
in properly hulling the infected berries.
The minute spores of the fungus may
be blown about by the wind or carried
from one plant TO another on the bodies
OF insects. Infection has been shown to
occur only when the epidermis of the
leaf IS punctured by insects such as the
aphis and torpedo fly (Siphanta acuta)
treatment to prevent serious losses |
from this fungus disease would naturally
come under two heads, first, improving
the general condition of the coffee by
better tillage of the soil and the use of !
the proper fertilizers; second, where