86 SPRAYING PEACHES, 
Of the various arsenicals available for use, well-made arsenate of 
lead has proved to be the safest. Shortly after the development of 
this comparatively new insecticide, it was at once extensively ex- 
perimented with on peaches by numerous entomologists and it was 
tried to a limited extent by peach growers. A single application of 
arsenate of lead in water did not result in injury so important as to 
prevent its use. However, when two or three applications were 
made, as is necessary in the control of the curculio, serious shot-holing 
and falling of the leaves and even burning of the fruit resulted, the 
latter, in extreme cases, falling to the ground. The use of lime with 
arsenate of lead lessened the danger of injury considerably, but used 
even in this way for two or three treatments, especially under certain 
weather conditions, resulted in extensive injury to foliage and fruit. 
When it was established that the self-boiled lime-sulphur wash was 
an effective fungicide and entirely safe as a spray for the peach, one of 
the interesting questions presented was whether arsenate of lead 
might be safely used with it to effect a combination spray for both 
insects and diseases. While on chemical grounds it appeared that 
the addition of arsenate of lead to the self-boiled lime-sulphur mixture 
would result in an important decomposition of the spray and greatly 
add to its probable injurious character, in practice the combined 
spray was found to be entirely safe. Observations extending over 
three seasons have failed to show any serious injury resulting from 
the use of this spray, even when as many as three applications were 
made. Thus, in the test of numerous brands of arsenate of lead at 
Barnesville, Ga., during 1910, carried out by Mr. E. W. Scott, of the 
Bureau of Entomology, peach trees were given three thorough appli- 
cations: (1) With arsenate of lead in limewater at the rate of 2 
pounds to 50 gallons, and (2) in the self-boiled lime-sulphur wash 
used at the same strength. In all cases very serious injury resulted 
to fruit and foliage on the plats sprayed with the arsenate of lead in 
limewater, whereas there was no discernible injury on the plats 
treated with arsenate of lead in the self-boiled lime-sulphur wash. 
It is not understood why the arsenate of lead apparently loses its in- 
jurious properties when used in the self-boiled lime-sulphur wash, 
though its safe employment in this way is most fortunate. 
In the schedule of applications only two arsenate of lead treat- 
ments are recommended, as these will measurably control the 
curculio and a third treatment would considerably increase the 
danger of injury. Where the curculio is very destructive, however, 
the grower should use his judgment as to whether a third application 
of the poison would be advantageous. 
The effect of the arsenate of lead upon the fruit is to increase 
its color notably. This increase in color from two applications in 
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