B. P. I.—654. 
SPRAYING PEACHES FOR THE CONTROL OF 
BROWN-ROT, SCAB, AND CURCULIO. 
INTRODUCTION. 
The peach-growing industry in the United States at the present 
time has become a very important one, being second in extent among 
fruits only to the cultivation of the apple. According to the 1900 
census there were in the territory east of the Rocky Mountains, which 
is subject to the troubles treated in this bulletin, approximately 
91,000,000 bearing peach trees. Since that time the number of 
bearing trees has increased by perhaps one-fourth, making a possible 
total of 113,750,000 trees. Careful estimates indicate that the 
quantity of fruit annually harvested by peach growers in this terri- 
tory is not less than 10,000,000 bushels. Thus the crop for 1910, 
although an unusually large one, was for the territory mentioned, 
probably not less than 12,000 000 bushels, with a gross valuation of 
about $12,000,000 to $16,000,000. 
Although many insects and parasitic fungi occur on the peach, 
comparatively few are of much economic importance. Of the dis- 
eases of the peach, the brown-rot (Sclerotinia fructigena (Pers.) 
Schrét.) and scab, or black-spot (Cladosporium carpophilum Thiim.}, 
are responsible for practically all of the damage to the fruit crop and 
the insect injury is limited almost entirely to the attack of one 
species, the plum curculio (Conotrachelus nenuphar Herbst.). 
The brown-rot probably causes more loss to peach growers than all 
other maladies of the peach combined, with perhaps the exception of 
“yellows,” which kills the trees outright. In the South the brown- 
rot often causes the destruction of half or even practically all of the 
crop, and throughout the territory under consideration the annual 
shrinkage in yield is perhaps 25 to 35 per cent of the crop, representing 
a valuation of about $3,000,000 to $4,000,000. Although the brown- 
rot is always present in the peach orchards of humid sections, causing 
a rotting of a certain proportion of the fruit, it becomes notably 
destructive only under certain weather conditions, when within a 
period of 10 days or two weeks it will spread so rapidly as to result 
in the destruction of practically the entire crop. Such disastrous 
440 b) 
