FLORIDA STATE HORTICULTURAL SOCIETY 
47 
The addition of arsenical poisons, where 
it is necessary to also control leaf-eating 
insects, is also suggested. 
NEED OF A DOUBLE SPRAY 
The need of a double spray has long 
been apparent to the writer, and the pre¬ 
ceding account is a brief record of his 
efforts to solve the problem. By a double 
spray is meant one that would serve both 
as an insecticide and a fungicide. Citrus 
growers especially need to spray more 
and more with fungicides on account of 
melanose, scab and withertip, and in do¬ 
ing so frequently have to follow up this 
spraying with an insecticide in order to 
control scale insects and whiteffies. If the 
control of the diseases and insects could 
be accomplished in one spraying a great 
saving would result. In this respect the 
preceding experiments can only be re¬ 
garded as preliminary, since the results 
obtained against insects were inconclus¬ 
ive. But a beginning has been made, and 
the writer hopes that the mixture experi¬ 
mented with can be perfected as an insec¬ 
ticide, especially against scales and white- 
fly. 
The writer is not the first one to at¬ 
tempt the perfection of a double spray, 
but the products obtained have not come 
into general use. Thus soap and bor¬ 
deaux have been mixed and used with 
some degree of success; lime-sulphur 
solution also has both fungicidal and in¬ 
secticidal properties, but is useful only 
against a few fungi and scale insects of 
the armored group with a waxy covering. 
Bordeaux being the standard fungi¬ 
cide, and emulsions of oils the standard 
insecticides, the difficulty encountered is 
that these two mixtures cannot be com¬ 
bined because the bordeaux breaks up the 
soap of the emulsions, resulting in the 
liberation of free oil. The problem 
therefore resolved itself into the possibil¬ 
ity of combining an oil directly with the 
bordeaux, as explained. 
The results with the linseed oil as .a 
“sticker” for the bordeaux are believed 
to- be important and it is hoped will prove 
useful. 
Discussion 
Mr. Hume: I have seen the work 
which Dr. Berger has been carrying on; 
in fact, I have been conversant with it for 
a good many months, and I believe Dr. 
Berger has found one of the most impor¬ 
tant things that have come up on the 
making of spraying mixtures, for a long 
time. Of course, he has not worked out 
all of the details, but he has given us the 
basis for a very great improvement. 
