4.4.2, QUEENSLAND AGRICULTURAL JOURNAL. [1 Dro., 1898. 
The tobacco from the Pongey Estate burnt excellently and gave a white 
ash; in a word, it was of prime quality. The other two were heavy and oily ; 
Kwaloe burnt well, but gave an ash, grey to black in colour; Lau Bentoe burnt 
black, and gave a black ash. 
A good yield of tobacco, as regards both quantity and quality, depends 
upon two factors, viz :— 
a. Sufficient quantities of plant-food in an easily assimilable form must 
be furnished to the growing plant on a suitable soil. 
 b. The plant-food ingredients applied must bring about the conditions 
that will render possible the development of a good leaf, rich in 
mineral constituents. 
A soil intended for the cultivation of tobacco must contain a sufficient 
quantity of humus, which is generally present in virgin soils or tropical fields 
that have lain fallow for a number of years. 
However, in most instances, the quantity of humus in the soil has become 
depleted in the course of time, and, moreover, circumstances do not always 
permit of letting land lie fallow for a number of years. When this is the case, 
an artificial application of humus to the soil is of prime importance. 
Humus may be applied to the soil in the form of stable-manure, compost, 
or oil-cakes, as well as by green manuring. 
When stable-manure is used, it should be applied yearly, as the weather 
conditions in the tropics accelerate decomposition. An annual application at 
the rate of about four and a-half tons per acre is sufficient. It is best to apply 
stable-manure in a half-rotted instead of a fresh condition. The use of liquid 
manure without litter should be avoided, on account of the high percentage of 
injurious chlorine it contains. However, as the planter in the tropics has but 
rarely sufficient quantities of stable-manure at his disposal, manuring with 
composts, &c., is of prime importance. 
In the following paragraphs the most essential plant-food ingredients 
required by the tobacco-plant, the forms in which they should be used, and 
the manner of their proper application, are fully discussed. 
NITROGEN. 
A sufficient amount of nitrogenous food is indispensable for the growth 
of the tobacco-plant. This constituent furthers the development of the plant, 
and tends to produce the highest yield during the short growing season. The 
effect of different nitrogenous fertilisers upon the quality of tobacco, though, 
varies considerably, and great caution must, therefore, be exercised in selecting 
the proper substances. It is advisable to avoid those nitrogenous fertilisers 
that contain nitrogen in the form of ammonia or in the organic state; those 
in which nitrogen occurs in the form of nitrate are preferable. ‘The former are 
liable to injure the good burning quality of the tobacco-leayes and, conse- 
quently, the good aroma. 
Experience has proven that nitrate of soda and nitrate of potash, in case 
the latter material can be procured, are the best sources of nitrogen for tobacco. 
Prof. A. Cserhati* holds that sulphate of ammonia produces. an increased 
yield, though only at the expense of quality; it decidedly injures the burning 
quality of tobacco, while nitrate of soda, even though applied in large quantities, 
has no harmful effect, provided, of course, that the plant is sufficiently supplied 
with the other essential plant-food ingredients. ‘Fish guano, tankage, wool- 
refuse, hair, and liquid manure must be avoided as much as possible; Peruv. 
guano also should be applied with caution. 
* Prof. A. Cserhati: ‘‘Versuche tiber die Brennbarkeit des Tabaks,” Journal fiir Landwirth- 
schaft, vol. 43, 1895, 
