146 INJURIOUS INSECTS OF IQO0Q AND IQIO. 
copper salts which are formed have an injurious effect on certain 
plants, among them the plum. In such cases, it is necessary to em- 
ploy some other fungicide, or, at any rate, to use very weak bor- 
deaux. Nevertheless, bordeaux, although being replaced to a cer- 
tain extent by some newer fungicides—notably the self-boiled, lime- 
sulphur mixture, is probably better, for general purposes, than any 
other. The proper strength of bordeaux is still somewhat uncer- 
tain; in fact it varies with conditions. The 5-5-50 formula has 
been regarded as standard, but excellent results have been obtained 
with weaker solutions, so it is probable that, for general work, a 
4-4-50 mixture will be sufficiently strong. 
The following are the fungicides in common use as sprays: 
bordeaux mixture, lime-sulphur wash, self-boiled lime sulphur, am- 
moniacal copper-carbonate, potassium sulphide. In addition to these, 
flowers of sulphur is often used, especially against powdery mildews, 
while corrosive sublimate and formalin are used in seed treatment. 
The amount of spray to apply will vary with the size of the tree. 
A tree having a spread of twenty-five feet in full leaf will require 
at least four gallons. The person just learning to spray ordinarily 
does not put on a sufficient amount, but stops before even half of the 
required amount has been given. This is one of the main reasons 
why spraying is not as successful as it should be in the hands of 
the beginning orchardist. A man must also learn to apply the spray 
evenly and thoroughly, and, with possibly one exception, not in the 
form of drops, but in a very fine mist. 
In our discussion of the plant pests, there are perhaps many 
forms that we have not mentioned. It may be that they have never 
been reported to us as being found in this state, or perhaps are only 
of local importance. The Divisions of Entomology and Plant 
Pathology of the Experiment Station are always willing and anxious 
to find out the various pests present in the state, and will welcome 
correspondence and specimens of diseased plants, or, in the case of 
insects, the enemies themselves. 
INSECTICIDES AND FUNGICIDES. 
Alphabetically Arranged. 
AMMONIACAL “COPPER CARBONATE. This iseenct 
as good for general purposes as bordeaux mixture. It is used in- 
stead of bordeaux when it is desirable to avoid the spotting of leaves 
or ripening fruit. It is prepared as follows: Weigh out the proper 
