228 
THE TROPICAL AGRICULTURIST. fOcT. 1, 1901. 
the cake would be likely to keep away some types 
o£ carterpillar, and other pests which spread by 
creeping from bnsh to bush, or which make their 
home ill the ground duriag the day. A strip covered 
with the cake between the tea and the jangle 
would probably keep out many of the pests which 
creep the surrounding land into the tea. 
The utility of the cake itself as an efficient sub- 
stitute for soap is very doubtfu'. Though it lathers 
well, on account of its saponin content, yet this 
does not necessarily mean that it has (;reat clean- 
sin" properties. IMevertheless it has been used for 
many years in China instead of soap, and it would 
probably be of -tome value for this purpose. One 
more use is made of the cake in China. It is there 
stated to be very effective as a poison for fish. 
On the whole, therefore, while I think there would 
be a market for the oil if it could be obtained in 
quantity and fairly cheaply it must, for the present, 
be a local one, and the material could hardly com- 
pete with oils already in general commerce, unless 
it be for the production of superior soaps. As a 
lamp oil it has distinct advantages which should recom- 
mend it for local consumption. The press cake is 
useless for feeding, and forms an inferior manure, 
though one quite good enough to apply to the land 
and also to cart for some di.'^tance, provided the 
cost on the garden does not exceed 8 to 12 annas 
per maund. It would probably be useful as an 
insecticide — both as cake against certain caterpillars, 
and as decoction which might replace that of a wild 
fern now used in Dibrugarh against Red Spider. 
The analysis of tha cake suppliyd by Mr. Deane was 
as follows : — 
Moisture 
Oil 
*Albuminoids 
Carbohydrates, &c. 
Woody Fibre 
fPhosphoric Acid 
Lime 
Alkaline Salts, &c, 
Sand 
♦Containing nitrogen 
tPhosphate of Lime 
HAROLD 
Oalcutta, August 12(h, 1901. 
11-99 
10-48 
12 00 
58-8i) 
2-G6 
•58 
.11 
2-78 
•60 
lOO'OO 
1-92 
126 
H. MANNi 
CULTIVATION OF SWEET 
POTATOES. 
BY PERCY G. WICKBN. 
The Sweet Potato [Batatus edulis) is a native of 
tropical South America. It was first introduced into 
Europe from Brazil, and has since proved to be well 
adapted for cultivation in the Australian States. It 
is a robust and hardy growing plant, and, given 
suitable soil and locality, is a prohfic bearer ; it la 
valuable both as food for man and cattle and should 
take a much higher position in our rotation of crops 
than it has done in the past. 
SOIL AND LOCATION 
A soil free from stones seems essential, and a sandy 
loam is the best for this crop. A stiff clayey soil 
causes the tubsrs to split when the weather beoomesi 
dry and hot. ■ ■, -i • 
The ground requires to be well drained, and m a 
dis'-rict that will be free from frost during the grow- 
ing months, viz : October toA pril. In many locahties 
the cuttings cannot be planted out until November, 
owing to the weather not being sufficiently warm to 
start the cuttings in time to plant out earlier. 
SEED BED. 
Many settlers fail in growing this crop from 
want of knowledge as to how to produce the cuttingg 
to plant out. The following is the method I hav» 
found most successful. Mark out a piece of land, in 
a sandy soil if possible, sufficiently large to allow 
the potatoes to be spread over. An area of 6 ft. 
by 6 ft. will be sufficient for 2 cwt. of potatoes. 
Then remove the top four inches of soil from the 
space and place on each side of the bed, now take 
your potatoes and lay on the bottom of the bed, 
taking care that they do not touch each other, and 
throwing out any that have started to go bad then 
put back the soil pieviously removed on the top of 
the potatoes, levellii g the bed and lightly packing 
down with the back of the spade. If the ground is 
very dry give a good watering. lu a few weeks' 
time, according to the weather, the young fchoots 
will appear above ground, when about three inches 
high they are ready for planting out. Start in one 
corner of the bed and remove the soil and lilt out 
the potato, and it will be found to be covered 
with young shoots, some potatoes having a few 
dozen, others up to a hundred shoots, according to 
the size of the potato. These shoots are now broken 
off from the tuber and are ready for planting out. 
The tubers can be replaced in the ground the same 
as before, and in a very short time a fresh crop of 
Bhoots will appear which can be removed in the 
same way, and if not too late in the season, a third 
crop may also be obtained. 
In localities where the season is late the follow- 
ing method may be adopted. Make a frame of 
same old boards, sink about J ft, in the ground and 
about 1 ft. ab'jve it. Throw out the first foot of 
soil and then place in the space about 18 inches of 
good stable manure and tread well down and cover 
with abont 4 inches of soil, leave for a couple of 
days, and then lay the potatoes on top of the soil 
the same as in the other seed bed and cover with 
3 or 4 inches of fine soil. The shoots will corns 
very quickly. If there is still any danger of frost, 
the beds must be covered at night with a light 
brush or calico screen, and the cuttings mast not 
be planted in the field until all danger of frost ia 
over. If the shoots appear in the bed in an irregular 
manner, it is better to pull them out by hand 
when required, than to disturb the whole tuber, 
which will be covered with small sprouts. Th« 
shoots will come away easily, and if pulled care- 
fully very few will be broken. The shoots should 
be kept in a box or wrapped up in a wet sack 
while being taken from the seed-bed to the field, 
and should not be left lying about exposed to the 
Ban. 
MANURB 
The Sweet Potato feeds largely on Nitrogen and 
Potaah with a smaller amount of Phosphoric Acid, and 
a manure containing these ingredients should be 
used. A mixture composed as follows; — 
3 cwt. Nitrate of Soda 
4 cwt. Kainit 
3 cv.'t Superphosphate 
per half ton would probably give good results. It 
should be applied in the ridges at the rate of 3 or 4 
cwt. per acre at the time of ridging up the grouni 
preparatory to transplanting the cuttiugs. 
PEEPAEATION OF LAND. 
The land requires to be well and deeply worked, 
and the crop responds well to deep cultivation ; being 
a summer crop it requires to obtain its moisturt 
during the dry weatht r and for this purpose sends 
its roots deep down into the soil. For this reason 
subsoiling is of great advantage to the plant as it 
is to most other plants. After the soil is well 
broken up it requires to be brought to a fine tilth 
by discing, harrowing, etc. As soon as the planti 
are nearly ready for transplanting the land should 
be drilled out into ridges, 3 feet 6 inches apart, by 
a drill plough, or a corn hilling disc is very useful 
for this purpose. The system I carried out for 
planting; was as follows : — A small hill was made 
by running the combining disc along the rows with 
