B. P. L— 538. 



THE CONTROL OF PEACH BROW X-ROT AND 



SCAB. 



INTRODUCTION. 



The susceptibility of peach foliage to injury from applications of 

 the usual copper fungicides has largely prohibited summer spraying for 

 the control of peach diseases. The diseases preventable by dormant 

 spraying, such as leaf -curl and the California peach blight, have 

 been easily overcome, but those requiring summer treatment have, 

 as a ride, been allowed to go unchecked for the want of a suitable 

 fungicide. The peach has therefore largely had to fight its own 

 battles against some of its worst enemies, with the result that the 

 growers of this fruit have annually sustained heavy losses. 



During the past few years the Bureau of Plant Industry has 

 endeavored to develop a fungicide that could be safely used on the 

 peach during the growing season to prevent some of the diseases of 

 the fruit and foliage. Various copper compounds in both liquid and 

 dust form were tested without satisfactory results. Experiments 

 with sulphur in various forms showed that the soluble sulphids were 

 even more caustic than Bordeaux mixture, and no encouragement 

 was obtained from the work until the so-called self -boiled lime- 

 sulphur mixture was tested. 



In the experiments of 1907, the results of winch were published in 

 Circular No. 1 of the Bureau of Plant Industry. it was found that 

 self-boiled lime-sulphur could be used as a spray on the peach without 

 injury to fruit or foliage. Brown-rot infections were held down to 

 10 per cent of the crop, while 73 per cent of the fruit on the unsprayed 

 trees rotted. The same treatment prevented the peach scab, or 

 black-spot, and some leaf diseases. 



Experiments conducted by the writers during 1908 at Marshallville, 

 Ga., Bentonville, Ark., and Xeoga, 111., verified the previous years 

 results and gave sufficient data to warrant the recommendation of 

 this mixture for general use in peach-growing districts where brown- 

 rot and scab are prevalent. The results of the 1908 experiments, 

 with suggestions for the treatment of brown-rot and scab, were pub- 

 lished in Circular Xo. 27 of the Bureau of Plant Industry. 



a These results were first reported by the writer at the Jamestown meeting of the 

 American Pomological Society, September 25, 1907, and were published in the pro- 

 ceedings of that meeting. They were- also presented before the Missouri State Hor- 

 ticultural Society. December 5. 1907, by Mr. F. W. Faurot, who assisted in the work. 

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