Ri ( ocMTiON OF Plant Bacti-riology in Europf 381 



Rolfs's direction, the new Sub-tropical Laboratory at Miami, 

 Florida, had been established. True, in 1902, for drug and 

 medicinal plant investigations, had located in Vermont and else- 

 where experimental plantations which included the growing of 

 plants in alpine regions. Fungicides and insecticides were still 

 being discovered. During the decade the self-boiled, so-called, 

 lime sulfur mixture came into usage as a fungicide to control 

 without injuring foliage a number of diseases, and later, replacing 

 the liquid, the use of dry sulphur in restricted application. 



At this time, in^the central west, the disease known as bitter 

 rot of apples, occasioning enormous losses, was being investigated 

 at the iVIississippi Valley laboratory and several state experiment 

 stations. Smith later said of this: '" 



In 1905 Scott, of the Bureau of Plant Industry, had remarkable success 

 in preventing bitter-rot of the apple by use of the Bordeaux mixture. This 

 disease which caused losses estimated at $10,000,000 in 1900, and very 

 great losses in the years immediately following, was controlled in his 

 experiments to the extent of 93 to 98 per cent. Expressed in bushels, the 

 sprayed trees (those that received 5 or more treatments at the proper time) 

 yielded 50 to 60 bushels of sound apples, while all the apples rotted on 

 the control trees, that is, A bore 1 sound apple, B, 6 sound apples, and 

 D, 2 sound apples. Tlie fungus Glowerella, cause of this rot, was exten- 

 sively studied by Hermann von Schrenk, later by many others. 



Among others, Cornelius Lott Shear, a plant pathologist of the 

 Department, contributed very valuable studies on Glomerella. 

 L. L. Harter, another Department plant pathologist, also was to 

 contribute very valuable work on sweet potato diseases.^' Smith 

 continued to hold in high esteem the work done in breeding dis- 

 ease-resistant plants. Full discussion of this subject belongs to a 

 later period. Yet, to illustrate, it may be pointed out that in 1896 

 asparagus rust swept over and alarmed large sections of the 

 nation, and by 1913 and before then J. B. Norton of the Bureau 

 of Plant Industry had bred plants ^^ resistant to the destructive 

 fungus. Smith's work mainly was now in indoor laboratory 



*" Fifty years of pathology, op. cit., 29. Concerning lime-sulfur and self-boiled 

 hme-sulfur as a.remedy against apple scab, peach leaf curl , brown rot of peach, etc., 

 see H. H. Whetzel, Outl. Hist, of Phytop., op. cit., 112-113. 



" Idem, 33. Smith said of this: " In 1913 Leonard Lee Harter described foot-rot, 

 a new disease of the sweet potato, and in 1913, 1914, and 1915, he published ori 

 stem rot of the sweet potato." See, T. S. Harding, op. cit., 81 for an account 



^^Idem, 33. 



