Aug. 1, 1902.] 
THE TROPICAL AGRICULTURIST. 
83 
SCIENTIFIC AND TECHNICAL 
DEPARTMENT OP THE IMPERIAL 
INSTITUTE. ^ 
RECENT EXPERIMENTS OX THE CULTIVATION 
OF TOBACCO. 
The tobacco industry has become so highly spe- 
ciftlised that it is necessary for the successful planter 
to become thoroughly acquainted with the scientific 
side of the processes involved in the caltilvation and 
fermentation of this material. Iho qualities of the 
tobacco leaf as regards the size, shape, thickness, 
flavour and aroma, the grain and general appearance, 
are so easily influenced, and so difficult to control, that 
its cultivation in new localities can only be attended 
with success after much experimental work. 
At the present time experiments are being under- 
taken in Ireland, on the culture of tobacco, by the 
Department of Agriculure. Some useful information 
on this subject is contained in Report No. 63 of the 
United States Department of Agriculture, and the 
following summary is compiled from this source. The 
report is a review of the experimental work conducted 
for some years past at agricultural experiment sta- 
tions situated in widely separated localities, and is 
intended to throw liglit upon the various problems 
connected with the growth and cultivation of tobacco. 
Methods of growing plants in seed beds. — At the 
Alabama State station various methods of staitiug to- 
bacco seed were compared. Seeds were started in 
several beds, some open and others covered with cheese 
cloth. During the first year of the experiments the 
greater number of plants in the open beds were des- 
Btroyed by a spell of cold weather, and during the 
second season they were injured by the flea beetle. 
In the covered beds the plants 3ame up well, grew 
rapidly and were not subject to insect attacks. From 
these results it is evident that under the climatic con- 
ditions of Alabama young tobacco plants are readily 
affected by low temperatures, and quickly killed by 
frosty weather. At the Colorado staition, in pursuing 
this work it was found tliat it took no loneer to pro- 
duce plants suitable for setting out by growing seeds 
in cold frames than by the use of the hotbed. 
The following method of germinating the seed at 
the Georgia station proved very successful. The seeds 
were placed in wine glasses and soaked in water for 
hal£-au-hour, the water was then poured off,— the 
glasses placed in saucers containing water, and a 
tumbler inverted over each glass so as to confine the 
moistened seed in a damp atmosphere. In about a 
week, when the seed had started to germinate it was 
sown in a cold frame, and with in a month from that 
time plants suitable for transplanting to the fields 
were obtained. 
In the experiments conducted at the Central Experi- 
mental Farm, Canada, the seeds were sown in hotbeds, 
and some of the plants thus obtained were trans- 
planted to cold frames before being set out in the 
fields. A striking difference was noticed between the 
plants set out from the hotbeds and those transplanted 
to the cold frames prior to setting out. The latter 
were stronger and grew more rapidly than those taken 
direct from the hotbeds. It was also found that if the 
plants were transplanted to a second hotbed before 
setting them out in the fields, the vigour was increased 
and the number lost in transplanting was materially 
reduced. 
In the districts where fungoid diseases gave any 
serious trouble it was found quite possible to sterilise 
the soil used for the plant bed. Boiling water, hot 
stones, or steam under high pressure may be used for 
this purpose. 
The size, weight, and condition of ripeness of the 
seed, as well as the method of planting, has been shown 
to have an important bearing upon the crop. 
Varieties oj Tobacco. — At Calhoun, the North Louisi- 
ana station— ten varieties of tobacco, namely, Cou- 
(jueror, Hester, Long-leaf Gooch, Ragland Improved 
Swoet Oronoko, White Burley, Comstock Spanish, 
Persian Ro^e, Improved Havana and Brazilian Ameri- 
can, were tested. Of these Comstoclc Spanish, Porsinn 
Rose, Improved Havana and Brazilian American, 
are oigar-leaf, and the rest aro described as bright- 
lemf varieties. The last-named, with the exception of 
White Builey, produced a leaf which, when cured, 
was of a lemon yellow colour ; they were more suc- 
cessful than the cigar-leaf varieties which, when 
cured, produced leaves too bright and in but small 
quantity. 
It was also shown that Conqnei'or, Long-leaf Gooch, 
Hester, Oronoko, and Ragland Improved, cured brighter 
than other bright-leaf v.arieties, and that Vuelta da 
Abfijo, Havana, Seed-leaf, imported Havana, Choice 
Havana, Little Dutch, and Pumpelly. produced a 
leaf of greater silkiness and finer texture than other 
cigar varieties tested. 
The kind of tobacco which can be grown in any 
district depends partly upon the climatic conditions 
and also upon the character of the soil. In testing 
varieties, therefore, consideration should in the first 
place be given to the type of tobacco adapted to the 
locality, to the soil, and the grade which the climatic 
conditions and soil may reasonably be expected to 
produce. 
Influence of distance in Plantinrj. — A study of the rela- 
tion of distance of planting to yield and thickness of 
leaf, was mane at the Wisconsin station. Plants were 
set 20 inches apart in rows 31 and 3S apart, and at 
intervals of 2-i inches in rows 42 inches apart ; close 
planting was found to increase the yield, and the plants 
nearest together in the row produced a thinner leaf 
than those further apart ; but lessening the dist:ince 
between the rows di i not have this effect. A distance 
of 31 inches between the rows was sufficient for the 
fall development of the plants. The surface area of 
the cured le?.ves per pound from the closest planting 
was 42-01 square feet, and from the widest planting 
40'86 square feet. 
Other experiments made with a viey to ascertain to 
what extent close planting may be advantageously prac- 
tised, showed that planting 1 foot apart in the row was 
not too close for Wiison Hybrid, the variety grown in 
this experiment. From these and other experiments 
it was concluded that too close planting interferes with 
the development of the leaves, while too large spaces 
between plants tend to produce coarse leaves. The 
dimensions of the leaf, thickness, elasticity, and size 
of the vines may all be more or less modified by 
giving the plants space or increasing the number in 
a row. 
fertiliser Experi>nc7(,ts.—Thevesxdts of experiments 
at Kentucky indicated that potassium, chloride, and 
sulphate, gave equally good results as fertilisers for 
tobacco, and that sodium nitrate produced a better 
quality leaf than other forms of nitrogen. 
Tests with complete fertiliser applications were also 
made. A yield of 1,460 lb. of cured leaf per acre was 
obtained after an application of 80 lb. of sodium 
nitrate, 80 lb. of dried blood, 160 lb. potassium chloride, 
And 140 lb. of double superphosphate per aDre, whereas 
by doubling the quantity of fertiliser the yield of leaf 
was increased to 1,620 lb. 
Fertilisers used on soil in a good state of fertility, 
were found to increase the yield of tobacco con- 
siderably, and potassium chloride proved more efiBcient 
than the carbonates of potassium and magnesium. 
At Calhoun experiments were conducted on red 
sandy and grey sandy soils- and it was shown that 
potash had little or no effect on the crop, but nitrogen, 
either in the form of sodium nitrate, ammonium sul- 
phate, cotton-seed meal, or dried blood, caused a 
marked increase in the quantity obtained. An appli- 
cation consisting of cotton-seed meal, acid phos- 
phate, and sulphate of potassium produce the best 
quality leaf. 
The effects of different fertilisers on tobacco were 
studied at the Virginia station. Five plots manure 
with complete fertilisers, all of the same cost pet acrei 
