ADDITIONAL EVIDENCE ON THE COMMIJNICABILITY OF PEACH 

 YELLOWS AND PEACH ROSETTE. 



By ERWIN F. SMITH. 

 PART I. PEACH YELLOWS. 



I. INTRODUCTORY. 



(1) Destructive nature of yellows. Peach yellows is a perplexing and 

 destructive disease. Oil all bands it is conceded to be one of the most 

 serious with which American fruit-growers have to contend. Form- 

 erly this disease was confined to a small district on the Atlantic coast, 

 but during the last twenty years it has invaded distant regions hitherto 

 free, and has entirely ruined the peach industry over very considerable 

 areas. Within ten years the disease has taken a fresh and very strong 

 hold upon orchards in the Delaware and Chesapeake region, the north 

 portion of the peninsula, and has destroyed thousands and thousands 

 of trees, rendering a great industry unprofitable or precarious. It 

 seems to be native to the eastern United States, having, so far as we 

 know, not been reported from California. Diligent inquiry also has 

 thus far failed to bring to light any notice of its occurrence in Europe 

 or other parts of the globe. 



The last negative evidence is from Mr. Newton B. Pierce, of the Di- 

 vision of Vegetable Pathology. From May to October, 1890, he was in 

 Mediterranean countries investigating vine diseases. Mr. Pierce trav- 

 eled extensively in France, Italy, Sicily, and Algeria, and looked care- 

 fully for this disease. He examined peach trees in a great many local- 

 ities, and observed the fruit in the principal markets, but failed to find 

 any traces of yellows. Inquiries of many persons devoted to the scien- 

 tific study of agriculture and horticulture also proved fruitless. They 

 had not seen or heard of anything resembling this disease. 



The distribution of the disease and the losses occasioned thereby 

 were set forth somewhat fully in my first bulletin and do not concern 

 us at this time. It is proper to state, however, that the losses continue 

 in the infected districts; that the disease has appeared in new localities ; 

 and that regions now healthy are also threatened. The yellows is 

 certainly as far south as southern Virginia and probably as far west as 



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