the ciirculio, by its punctures, opens the way for brown-rot infection 

 of peaches, plums, etc., its control becomes doubly important. 



While the curculio is not of itself the cause of brown-rot, its work 

 very greatly favors the disease. Furthermore, it is practically certain 

 that the curculio distributes the spores of the fungus, and in the course 

 of its feeding and e^g laying actually infects the fruit with the fungus. 



As is well known, the foliage of the peach and other stone fruits is 

 especially sensitive to sprays, such as Paris green and Bordeaux mix- 

 ture. This has largely prevented the use of Bordeaux mixture and 

 other copper compounds for the control of peach diseases. While it 

 has been known for several years that arsenate of lead could be used 

 in the treatment for curculio, some injury has resulted, and on account 

 of the well-known sensitiveness of peach foliage entomologists have 

 been cautious about recommending it. The combination treatment for 

 fungous diseases and insect enemies so successful in the treatment of 

 the apple, grape, etc., has, therefore, not been possible on the peach. 



The development of the self-boiled lime-sulphur mixture, however, 

 as a fungicide has made possible the control of the brown-rot and some 

 other peach diseases. The experiments made by the Bureau of Plant 

 Industry, with the self-boiled lime-sulphur mixture on the peach, cov- 

 ering three years— from 1907 to 1909 — have shown conclusively that 

 when properly made it is perfectly harmless to the foliage, fruit, and 

 tender growth of the peach, and that it will satisfactorily control brown- 

 rot, peach scab, and other fungous diseases. 



In experiments conducted during the past season it was found that 

 the arsenate of lead could be combined with the self-boiled lime-sulphur 

 mixture for spraying peaches, and that this insecticide was apparently 

 less injurious in the combination than when used alone, and that the 

 combination was entirely successful in controlling the scab, brown- 

 rot, and curculio. The addition of arsenate of lead, as shown by these 

 and other experiments, has been practically without injurious effects 

 where not more than two applications have been made. Three appli- 

 cations, however, of an arsenate-of-lead spray are likely to cause 

 shot-holing of the leaves and an excessive reddening of the fruit, and 

 under certain weather conditions such symptoms may appear as the 

 result of only two applications of the poison, though ordinarily not to 

 an injurious extent. The great benefits to be derived from spraying, 

 it is believed, will much more than offset an}' possible slight injury. 



SOME RESULTS OF SPRAYING. 



In experiments conducted in the Hale orchard, at Fort Valley, (J a., 

 during 1909, by the Department of Agriculture, the practicability 

 of the control of peach scab, brown-rot, and the curculio was 



n For a detailed account of these experiments, see Bulletin 174 of the Bureau of 

 Plant Industry, U. S. Department of Agriculture. 

 [Cir. 120] 



