May, 1919 
WISCONSIN HORTICULTURE 
will give satisfaction: “Friend,” 
“Mistry, ” “Vermorel. ” The 
finess of the spray is partly regul- 
ated by the size of the opening 
in the disc of the nozzle. This 
opening should not be over one- 
sixteenth of an inch in diameter, 
and preferably somewhat less. 
SPRAYING MATERIALS 
Insect sprays — Of the poisons 
for chewing insects, none is safer 
to use and more satisfactory than 
arsenate of lead. The paste form 
is most commonly found in the 
market, and is used at the rate of 
from two to three pounds to 50 
gallons of water. 
Of the contact poisons, some 
nicotine solution is most useful 
for market gardeners to use 
against plant lice. An addition of 
sufficient fish oil, soap to this mix- 
ture to make suds will increase its 
efficiency. 
Bordeaux mixture is the most 
suitable spray for use against 
plant diseases. It is made by dis- 
solving four pounds of copper 
sulphate crystals in 25 gallons 
of water, slaking six pounds of 
good lump lime, and stirring it 
into 25 gallons of water; and 
then combining the two by pour- 
ing them simultaneously into a 
third barrel. The resulting mix- 
ture will be robin’s egg blue in 
color, and contain four pounds of 
copper sulphate, six pounds of 
lime, and 50s gallons of water. If 
the tank to be used holds 100 
gallons, double the above quant- 
ities. 
What is called a stock solution 
may be made by dissolving copper 
sulphate in one barrel in the pro- 
portion of one pound to one gal- 
lon of water; and by slaking lime 
in another barrel in the same 
proportion. As much as 20 to 30 
pounds of each material can be 
placed in each barrel. These 
barrels should be kept covered to 
prevent evaporation and main- 
tain the right proportion of one 
pound to one gallon of copper 
sulphate in one case and lime in 
the other. Made in this way, these 
stock solutions will keep indefin- 
itely. When Bordeaux is to be 
made, three more barrels are 
needed. Into one is placed four 
gallons of the stock solution of 
copper sulphate, after the stock 
solution has been thoroughly 
stirred. This in turn is diluted to 
make 25 gallons. The lime solu- 
tion is handled similarly in anoth- 
er barrel, six gallons being used 
instead of four as for the copper 
sulphate. The two are then com- 
bined by pouring each diluted so- 
lution into a third barrel at the 
same time. In this way the work 
of dissolving copper sulphate and 
slaking lime preceding each 
spraying, is not necessary. 
There are many prepared ma- 
terials on the market to take the 
place of home made Bordeaux, 
some of which seem satisfactory. 
In most instances arsenate of lead 
is combined with this to make a 
combination insecticide and fung- 
icide. Under normal market con- 
ditions it is not economical to 
use the combined insecticide and 
fungicide where the fungicide 
alone is needed. However, at the 
present time, with copper sul- 
phate costing three times its 
normal price, the use of such a 
material is advised where there 
is no danger from the use of the 
arsenate of lead. Every caution 
should be exercised in the use of 
any poison spray on vegetables 
which are used on the table 
without trimming, or where the 
edihle portion is exposed in the 
field. 
115 
TIME TO SPRAY 
Spraying is to prevent loss by 
insects and disease just as cul- 
tivation is to save soil moisture 
and prevent the growth of weeds. 
There must be prevention. The 
time of attack by insect pests is 
fairly well known. Careful ob- 
servation will take note of the 
first intruders. Where poison 
sprays are to be used the plants 
should be sprayed shortly before 
the pest is due. Squash and 
Potato bugs often precede the 
crop and stand ready for the crop 
to come through the ground. 
Early spraying is essential. 
Where a contact spray is neces- 
sary, as for plant lice, the lice 
must be present before the spray 
will work. The application should 
be early before considerable 
damage is done. 
For the fungous diseases thor- 
ough spraying before the attack 
is most important. A knowledge 
of the occurrence of the disease 
in the community is a very force- 
fid warning of the need for im- 
mediate action. 
METHOD OF APPLICATION 
Water is simply the carrier of 
the poison and the copper com- 
pound, and has no other part to 
play. After the application is 
made, the water evaporates and 
leaves these compounds to do 
their work. If portions of a plant 
are left uncovered, there is chance 
for insects to feed and disease to 
start. The necessity for high 
pressure and a good nozzle has 
been emphasized. The combina- 
tion results in a fine mist-like 
spray which spreads evenly, will 
cover foliage without drenching 
or waste of material, will make 
rapid spraying possible and pre- 
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