6 SPRAYING PEACHES. 
outbreaks are likely to occur during moist, humid weather as the 
fruit begins to ripen. The brilliant prospects of the orchardists are 
thus within a few days obliterated as if by fire. 
The peach scab is the only other destructive disease of the fruit in 
the eastern United States, and, while it does not occur in such sud- 
den and disastrous outbreaks, the sum total of the injuries caused 
by it are very important, resulting in a shrinkage in crop values of 
perhaps $1,000,000 annually. This disease occurs all over humid 
America where the peach is grown and is especially troublesome 
east of the Allegheny Mountains. It not only renders much of the 
fruit unfit for market, but so mars the appearance of the marketed 
fruit as to reduce its value. 
The plum curculio is of scarcely less importance in its relation to 
the successful production of the peach than the diseases above men- 
tioned. By its punctures of the fruit in feeding and egg laying and 
the injury resulting from the larve, or grubs, within the fruit it brings 
about a reduction in yield of a valuation amounting to perhaps not 
Jess than $3,750,000 annually. The puncturing of the fruit also 
greatly favors the brown-rot, and curculio control is a prime essen- 
tial in preventing losses from this malady. Although the plum 
curculio is very generally distributed eastward of the Rocky Moun- 
tains, it is especially abundant in the Middle and Southern States. 
During years of full fruit crops its injuries are less important, sim- 
ply more or less thinning the fruit; but when the crop is light little 
fruit may escape its ravages. 
The troubles mentioned have more than kept pace with the devel- 
opment of the peach-growing industry, and the cultivation of this 
crop, especially in the South, has become more and more hazardous, 
Practical means for their control have, therefore, been most urgently 
needed, and much attention has been given by investigators of the 
Department of Agriculture and of the various agricultural experi- 
ment stations to supply this want. While it has been possible by 
the use of certain sprays, such as Bordeaux mixture and Paris green, 
to effectively reduce these troubles, the sensitiveness of the foliage 
and fruit of the peach has practically prevented their employment, 
and the peach grower has been almost helpless against them. A 
spray effective in the control of these troubles and which at the same 
time may be used with perfect safety on the trees and fruit has been 
the most important requirement to place the industry on a reason- 
ably secure foundation. 
Experiments begun by the Bureau of Plant Industry some three 
or four years ago and carried out under varying climatic and other 
conditions in different parts of the eastern United States have estab- 
lished beyond question the effectiveness of the self-boiled lime- 
440 
