April 1, 1903.J Supplement to Uie " Tropical AgricaiturisV' 
719 
of the muscles of the spine. Improvement is 
slow (assuming a change of diet) but giadunl. 
There is uo fever. Mules appear to be more 
susceptible. 
NEW VARIETIES OF SWEET POTATOES. 
(J. W, Mollison Inspector- General of Agriculture 
for India.) 
I imported three American varieties of sweet 
potatoes last year. These were first tried on the 
Bombay farms. The first Bombay crop was 
propagated from imported tubers, the second crop 
was propagated in the usual way from cuttings. 
It was planted on the j8th of April and was 
lifted at the end of July. A large number of 
cuttings were distributed from the first crop to 
various parts of India; therefore only about 
one-fourth acre was planted for the second crop. 
The area was too small for very reliable outturn 
figures. I give, however, the reults as under: — 
lbs. per acre. 
Nansemond ... ... 14,470 
New Jersey ... ... 16,782 
Virginia . . ... 21,413 
The land was not directly manured but was 
in good condition. The produce from the whole 
plot d^ih acre) was sold for Es. 90, or Es. 303 
per acre. 
2. The crop also yielded a very large number 
of cuttings which have been used for distribution 
and for planning an extended area at the Bombay 
farms, I have now seen these varieties growing 
on various descriptions of soil in the Punjab, 
Bengal, Central Provinces and Bombay. The 
plants everywhere show great vigour of growth. 
1 believe the introduction of these vrarieties to 
be an undoubted success. It is important, there- 
fore, to have these American varieties tiied in 
all districts where the crop is important. 
Cuttings can be supplied during October for 
experimentcl trials if applications are made to 
my ofKce at Nagpur. 
3. The crop does best on deep alluvial soil of 
a sandy or loamy character, but will also do 
well cu any free working naturally dry soil of 
fair depth. The best crops are grown under 
irrigation in the rabi season; but in districts 
where the cold of winter is severe and the toial 
rainfall is not excessive, the crop uill probably 
do best if planted in June-July. The American 
varieties are not likely to thrive on deep black-soil. 
4. The results reported from Poona show 
that the tubers were all sound and of gocd si. ape 
and size. They were proved to cock well and 
have good flavour. The A'irgiuia variety produced 
4 or 5 tubers from each plant. These tubers 
were larger than those usually obtained from 
indigenous varieties. The Nansemond and New 
Jersey varieties produced 16 to 18 tubers from 
one plant. These tubers were smaller than those 
from ordinary indigenous varieties, but were all 
of good marketable size. The tubers of each 
variety grew not fur from the surface in clusters, 
and were much easier to dig than those of ordinary 
Indian varieties. 
5. The cultivator of sweet potatoes is put 
to no particular expense for seed. lie simply 
uses as cuttings the haulins of a previous crop. 
These cuttings may have to be planted in a nur- 
sery. A small nur.-ery planted in March when 
the rabi crop is harvested will provide cuttin-^'s 
for planting a kharif crop in July, and this crop 
will, in its turn, provide cuttings for the next 
rabi crop which should be planted in October- 
November. 
6. Full details regarding methods of culti- 
vating this crop are given in Volume III of my 
Agricultural Text-book, but for easy reference I 
may refer to important points here. 
7. The soil should be of suitable class and be 
well worked by repeated ploughiiigs and harrow- 
iugs. Beds should be formed if irrigation is 
required. The crop can be propagated from tubers, 
but more economically from cuttingg or pieces of 
mature stem having four nodes to each cutting. 
The best cuttings are got from the middle portion 
of the stems. The date of planting the main 
crop will depend upon the uiual custom in any 
particular district. The main crop is sometimes 
planted in flat beds and sometimes. .in ridges made 
about 18 inches apart. The latter method is 
preferable. The cutting.-, it planted in ridges, 
should be buried half way between the base and 
the apex and on each side of eiich ridge. Each 
cutting should be planted with two nodes buried 
and two ends above ground. A vigorous growth 
of long trailing stems is soon produced if the 
crop is healthy and very little hand-weeding is 
required. No irrigation is given in the rains, but 
if planted in the rabi seasou irrigation is necessary 
every 8 to 15 days according to the character of 
the soil, 
8. The sterns when in contact with wet soil 
after rain or irrigation becume attached to the 
soil by rooting at the nodes. This must be 
prevented, otherwise small tbin tubers" of no 
marketable value form at each point of attachment. 
The tubers which form at the main root, moreover 
will not grow so large as when the stems are kept 
quite free. The stems during growth must be 
repeatedly lifted clear from the ground and turned 
over to prevent the formation of these roots. 
These operations must be dene often if the crop 
is good and the foliaage luxuiiant, and always 
with care, so that the stems aud leaves are 
d imaged ns little as po.ssible, 
9. In a luxuriant crop the growing points 
of the long trailing stems may he pruned off 
without damaging the crop in any way. These 
prunings provide a delicate vegetable. 
10. The crop should be lifted when the 
stems near the grosving point get hard and fibrous 
and the h.aves turn yellow. The vines should 
be reaped close to the ground and cuttings 
selected for a nursery. Such of the vines or 
porticn.s thereof as are green and succulent can 
be used as cattle fodder. Irrigation water should 
be withheld as the crop ajproaches maturity. 
Wheii the tubers are ripe they should be lifted 
at C!!ce, otherwise much damage will be done by 
rsat aud white-ants, &c. 
