6 PREFACE. 



Bureau of Plant Industry. These are now being tested in trials con- 

 ducted in cooperation by the Bureau of Plant Industr}^ and the State 

 experiment stations in Vermont, Florida, Colorado, and Oregon, and 

 by the Bureau at the Arlington Experimental Farm, near Washing- 

 ton. In order fully to acclimatize the foreign varieties, these trials 

 will be continued for three 3'ears before a tinal report is made on their 

 adaptation to American conditions. This test, together with the 

 review of our present knowledge contained in this bulletin, will estab- 

 lish a proper foundation for future eli'orts in breeding better and more 

 disease-resistant varieties. The field for such work is very large. 

 Up to the present time most of the breeding has been for resistance 

 to the late-blight {PlnjtopJdliova infestan fi),2indi this will continue to be 

 the principal problem in the northern tier of States; but there is also 

 much promise of success in securing new varieties to resist scab, dr}"- 

 rot, bacterial blight, and other troubles, which in the Southern and 

 Western States are more injurious than late-blight. It is hoped tliat 

 potato specialists will give increasingly careful attention to this fea- 

 ture in their breeding and testing of varieties, for it is only by such a 

 general interest and effort that the desired information can quickl}^ be 

 secured. 



Albert F. Woods, 

 Pathologist and Physiologist. 



Office of Vegetable Pathological and 



Physiological Investigations, 



Washington, D. C'., October 6, 1905. 



