90 



.Illinois began his studies on the fungous troubles of the Mississippi 

 Valley and threw new light on the nature of blight in pear and apple. 

 His discovery and proof of this as a bacterial trouble, placed these 

 organisms, for the first time, as agents of disease in plants. 



" It was in our third period of development that the investigating 

 spirit came especially to the front. This last period extends from the 

 founding of our experiment stations in 1887 to the presenl day. The 

 experiment stations in most cases vjrovide for a botanist on their staff, 

 and usually his work as an investigator led him to deal more largely 

 with fungi than with flowering plants. The experiment stations, 

 too, provide facilities for research that were not enjoyed before. The 

 work of the stations has served to strengthen and multiply the research 

 work of our colleges and universities. At the time these stations were 

 established the Government also began to extend its botanical work, 

 especially in the line of vegetable pathology. 



'• I think we can safely state that the most characteristic 

 thing of to-day is the tendency to specialize. We can still occasionally 

 find the old type of naturalist as an investigator, tucked away in some 

 academy of science or local college, but he is a rare individual. The 

 man who hopes to do something of permanent value must select a 

 limited field in which to work, and then bend his energies to study it 

 minutely. He may be a general botanist or even naturalist, but he 

 does not want to investigate in general botany or natural history. To 

 succeed he ought to be a broad man working narrowly and deeply. 



" I have no doubt the line of study most interesting to you as hor- 

 ticulturists is that of the plant pathologist, especially of the one study- 

 in-- preventive treatments. I have not emphasized this phase of the 

 subject before, partially because it has been the side repeatedly pre- 

 sented to you and partially because the more I learn the more I realize 

 that the terms parasite and saprophyte contrast more strongly in print 

 than do the real things in nature, and so 1 am led to believe that any 

 botanist gives aid to the science, even in its economic bearings, not so 

 much from the point of view from which he works but by the thorough- 

 ness with which he works. 



"There have been four general lines followed in the treatment or 

 prevention of fungous diseases. These are spraying, seed treatment, 

 soil treatment and plant breeding. A fifth might possibly be added 

 which would include such general precautions as the selection of good 

 seed or stock, proper pruning or picking to rid the plant of diseased 

 members, rotation of crops to avoid accumulation of disease, and des- 

 truction of refuse to limit the breeding of saprophytic stages or winter- 

 ing of spore forms. On the whole spraying has proved to be the most 

 general and efficient treatment. Spraying experiments have been tried 

 lor almost all of the important troubles and remedies found for not a 

 few. Bordeaux mixture has proved its supremacy as a fungicide ; 

 the value of spraying resides in its being preventive rather than cura- 

 tive; success of prevention lies in starting before the appearance of 

 disease, by repetition as needed during period of infection and in the 

 thoroughness of the work; a final factor determining greater or less 

 success, and one that cannot be controlled, is season. Spraying, appa- 

 rently, has come to stay since it has become a common practice in the. 

 larger orchards, vineyards and even in potato fields. 



