The Hawaiian star. [volume] (Honolulu [Oahu]) 1893-1912, 1911-06-07

growth.
Experiments are also under way
with a number of legumes and other
crops, some of which were recently
imported from Japan, to be used in
rotation with rice in order to main
tain the high yield which has hitherto
prevailed in Hawaii.
Pineapples.
J. In connection with the study of
manganese in. the soil as affecting
the growth of pineapples, expert
ments have been made with a num-
Der of crops which could possibly be
grown in rotation with pineapples or
to replace pineapples in the mangan-
ferrous Soils For this purpose corn,
rice and various other cereals, tobac-
CO, cotton, legumes, garden vege-
tables, and fruit trees were used. 1t
has been found that manganese in
variably causes a following of all
the leaves and a premature falling
OF the lower leaves on all plants with
which experiments have been made.
The plants may subsequently become
green, just before the fruiting period,
at which time vigorous growth may
be observed for a short period. The
ultimate outcome, however, is in all
instances a decidedly stunted growth
and small yield. The root system in
manganiferous soils is peculiar in
the length and fineness Of the small
roots. The ultimate outcome in pot
experiments is root system strik-
ingly different from that in ordinary
garden soils. Apparently the ex-
treme ineness of the roots is due TO
the lack of resistance which they
meet in penetrating manganiferous
soils These soils invariably remain
loose like ashes, no matter how fire.
quently or heavily they may be irri-
gated.
In the fertilizer experiments with
pineapples, which are being contin-
ued by the chemist, it has been found
that phosphates, particularly acid and
reverted phosphates, have a bene-
fetal effect upon the growth of the
pineapple plants, probably for the
reason that these materials tend to
render the manganiferous salts in
the soil less soluble. Lime, on the
other hand, is decidedly injurious on
manganiferous soils, as shown by the
experiments of the station and by
tests which have been tried by grow
ers on commercial scale. The in
furious effect of lime is possibly due
to the fact that it helps to furnish
conditions favorable for the forma-
ton of the higher oxids of mangan-
ese, which are the most injurious
salts of this mineral.
A study of the ripening of pine
apples has disclosed the fact that the
sugar content of the fruit is derived
exclusively from the leaves of the
plant and does not increase after the
fruit has been removed from the
plant. If pineapples are picked green
and allowed to ripen the sugar con-
tent at complete ripeness is the same
as it was when the fruit was re-
moved from the plants. An analysis
of the fruit shows that they contain
no substance which can be changed
into sugar during the ripening pros
ess Fruits picked too green and al
lowed to ripen, therefore, lack
greatly in sugar content and in
flavor.
Horticultural Investigations.
Satisfactory progress has been
made in propagating avocados, espe-
cially by budding. The method re-
ported in the last annual report has
been put into operation on other
trees, and the results thus far OBJ
tanned are very promising. A MUIR
Der of difficulties, particularly the
drying of the bud, have been success
Iully overcome.
Attention has been given to the
varieties of avocados to be found in
the Territory. There appear to be
quite a number of recognizable varie-
ties, but most of them have not been
definitely named. Four varieties of
special merit have received attention
on account of their being especially
adapted to shipping, extra late, ex.
ira early, or of exceptional quality.
Similarly with mangoes, the meth
DDS of propagation reported in the
last report and in Bulletin 20 of this
station, have continued to give good
results. In one case fruit was borne
upon graft within eighteen months
after insertion. Continued tests of