88 THE PLANT WOELD 



THE ASPARAGUS RUST.* 

 By Byeon T>. Halsted. 



THE nist of tlie asparagus is caused by a fungus that was described 

 b}^ DeCandolle as Puccinia asparagi in the year 1805. From this 

 it is seen that the rust upon the asparagus has been known to 

 science for nearly a hundred years. No search of the early writings 

 upon gardening has been made for a mention of the trouble, but it is 

 reasonable to suppose that more or less of this fungus has existed be- 

 yond the history of man. 



The only mention of its being found in the United States pre\'ious 

 to 1896 is by Dr. Harkness, and correspondents in California inform us 

 that the rust is not found there at the present time. It is impossible to 

 account for the unusual outbreak of the rust in the eastern United 

 States in 1896, which, after a full correspondence with botanists, horti- 

 culturalists and asparagus growers, seemed to be limited in that year 

 to New England, Long Island, New Jersey and Delaware. In 1897 it 

 was gathered, by wide correspondence, that the rust had spread only 

 alang the Atlantic Coast, and as far south as South CaroKna, where it 

 became a genuine source of alarm in the large asparagus fields around 

 Charleston; but as yet the vast interior and western United States were 

 free from the nist. In 1898 the disease had spread westward as far as 

 Michigan, and southward to Georgia, with a full measure of it in Penn- 

 sylvania, During the year 1899, with careful observers in each State 

 and Territory, one is able to add Ohio, Indiana, Illinois, Kansas, and 

 North Dakota to the infested area. For the year just closed, it is 

 reported as being in evidence in Nebraska, South Dakota, and last of 

 all, the gap between Illinois and the west is filled by its being found in 

 Iowa. 



It is not likely that the spread of this disease has been phenom- 

 inally rapid, but on account of its first coming into the country at this 

 late date when the Experiment Stations are established, and spies, so 

 to say, may be set upon its movements, it becomes possible to note its 

 progress both in direction of the invasion and the rate of its advance. 

 In order to offer some clue as to the method of the dispersion of this 

 rust, it may be interesting to mention in passing some personal obser- 

 vations in the field. For example, there were two asparagus beds 

 standing at right angles to each other; and separated by a small place 

 containing a house and barn. In position it was like the letter T, but 

 with the horizontal top piece somewhat removed from the upright. One 



* This paper has been prepared at the request of the Editors. In substance it has 

 appeared before in another journal, but its exceptional interest make? its repetition 

 desirable. 



