452 QUEENSLAND AGRICULTURAL JOURNAL. [1 Junn, 1902. 
is liable to burn the foliage. Quicklime added in the making up of these 
mixtures will make the poison stick to the leaves better and will also limit the 
burning action onthem. ‘Too much lime must not be added, as it will clog the 
nozzle of the spray pump. Four of lime to one of Paris green is about the 
best proportion. According to “Lodeman,” sugar added to these sprays will 
make them adhere to the leaves better. This is especially applicable to copper 
spray solutions, on which I shall speak later. 
The insects that do not gnaw the outside of the leaves and plant would 
not be affected by poison that is sprayed on the outside ; therefore, a different 
application is needed—one that will kill by coming into contact with the insect. 
For soft-bodied insects and caterpillars, tobacco water, tar water, quassia, and 
many other cheap remedies are used, but are only good for aphis, caterpillars, 
&c. Some insects, such as the woolly aphis and cottony cushion scale, have a 
coating of a waxy substance over them which makes them proof against the 
abovementioned sprays, the wax preventing the insecticide from reaching their 
bodies. To kill them, the waxy coat must be destroyed, and some substance that 
dissolves it is mixed with the spray. Kerosene is the best stuff to accomplish 
this, but if it were sprayed on to a plant in a pure state it would not only 
destroy the insect, but would also kill the plant. To prevent this, an emulsion 
is made with soap, and this is generally a hard job, as a perfect emulsion is 
necessary, and no kerosene must be left unemulsified or it will burn the plant, 
and also destroy the india-rubber parts of the spraying outfit. One formula for 
making an emulsion is as follows:—Churn 2 gallons of kerosene and 3 Ib. of 
common soap in 1 gallon of water till a perfectly stable emulsion is formed. 
This is then diluted to 30 gallous with water and is ready for use. Resin with 
caustic soda makes another good spray for scale insects in general. These 
sprays cost a great deal more than tobacco water, &c., and are more trouble to 
prepare, but can always be relied upon if used judiciously. Judgment must be 
used in spraying not to use a strong spray on a tender-foliaged plant. Washes 
for scale insects are made from sulphur and lime, and prove very eflicient. 
Sprays for fungus pests naturally differ entirely from those used on insects, 
and are those that will burn or otherwise destroy the fungus without dfmaging 
the host plant. Fungi are divided into two classes—those growing on dead or 
decaying tissue and those feeding on living tissue. To the latter class belong 
the fungi which generally attack cultivated plants. Some fungi start their 
mischievous work in the centre of the plant, and this makes it very difficult to 
destroy them—in fact, it is practically impossible to get rid of them without 
destroying the plant itself. Others confine their attacks to the surface of the 
stalks and leaves, and it is with the latter we shall principally deal. 
The only chance one has of eradicating a fungus is to take it in hand 
before it becomes firmly established and before its spores have penetrated into 
the tissue of the plant. When this happens the tissues of the plant must be 
destroyed to kill the fungus, and it is plain that the cure is worse than the 
disease. All sprays and applications must be preventives, as a cure is 
impossible when the fungus once becomes firmly established, unless it is one 
that confines its attacks to the surface of the plant. The best method of 
preventing attacks of these diseases is by covering the stems and branches 
with some dressing (care being taken to fill all the little crevices in the bark), 
which either prevents germination or destroys the spores as soon as they have 
germinated. © 
The materials in general use for the prevention of fungus pests are 
bluestone, lime, and sulphur, bluestone being the most important. These 
are made up into various sprays and applications, the chief of which is 
Bordeaux mixture. Some say that if London purple is added at the rate of 
1 1b. per 100 gallons of mixture, a more effective spray is formed, but dis- 
cretion must be used in so doing. Bordeaux mixture may be called the 
standard spray for fungi. Lime and sulphur boiled in water in equal propor- 
tions is a remedy for mildews. Other washes are made of sulphur, lime, and 
salt. The fungus ‘“ Oidium” of the grape is entirely prevented and cured by 
