I02 



THE CANADIAN HORTICULTURIST. 



Fig. 2257. Peach Curl, Untreated Leak. 



1900, and was largely instrumental in giving 

 rise to the belief that spraying was of no 

 ^ value as a remedial treatment. According 

 to this view, the threads of the fungus in the 

 spring extended into the leaves of the young 

 shoots, and there formed a net-work o^ 

 threads which finally caused malformation 

 and death of the leaves. If this view be the 

 correct one, it is manifestly of little or no 

 value to spray, for the fungal threads are 

 within the plant and beyond the influence of 

 the Bordeaux. 



Frequently, however, reports were re- 

 ceived from reliable experimenters that the 

 Bordeaux mixture did exert a controlling in- 

 fluence on the disease. Messrs. Craig, Orr 

 and A. H. Pettit obtained satisfactory re- 

 sults in Ontario in 1897, 1898 and 1899, 

 while Prof. Bailey, Dr. Duggar and Dr. 

 Murrill reported excellent results in New 

 York. Other instances might also be given, 

 but these are sufficient to show that pro- 

 bably the disease was prevented from 

 spreading to the leaves because the spores 

 did not have an opportunity to germinate. 



Newton D. Pierce, of the Department of 

 Agriculture, Washington, D.C., began the 

 investigation of the Peach-Curl problem as 

 far back as 1893, and carried on an elabor- 



ate series of experiments in co-operation 

 with peach growers in many of the states. 

 His results were very conclusive as to the 

 value of Bordeaux mixture as a remedial 

 treatment, and he does not hesitate to state 

 that the disease can be efficiently controlled 

 by early spraying. 



Mr. Pierce is of the decided opinion that 

 the main source of infection of the leaves in 

 spring is the spores, which find their way to 

 the leaf buds, for over 90 per cent, of the in- 

 fections can be prevented by a single spray- 

 ing. Success depends upon an early appli- 

 cation of the Bordeaux. The first spraying 

 should be done in April when the buds are 

 beginning to swell, or from one to three weeks 

 before the opening of the blossoms in the 

 spring. If much wet weather follows, an- 

 other spraying should be made after the 

 blossoming period. 



The writer is quite aware that many 

 orchardmen may be quite skeptical in this 

 matter of Peach-Curl control, but facts are 

 accumulating so rapidly that there should be 

 but little doubt that Bordeaux mixture, ap- 

 plied at the proper time, applied in the proper 

 way, after being properly made, will control 

 the Peach Leaf-Curl. 



The peach industry is a large one, and 



Fig. 2258. Peach Curl, Treated Leaf. 



