environmental conditions influenced the results of the treatment and it was desira- 

 ble to develop a method which would be suitable for every year under a wide range 

 of conditions. The AAriters beheve that after six years of experimenting they are 

 ready to publish definite recommendations. In the present bulletin there are also 

 presented the experiments and data on which the recommendations are based, along 

 with the results of some other accessory lines of investigation on onion smut. 



HISTORY OF THE DISEASE 



Onion smut is probably a disease of American origin, although its history previ- 

 ous to 1857 is unknown. Onions have been cultivated and used by all the civilized 

 races of the world in all ages. Starting with the inscriptions on the pyramids, there 

 is an enormous amount of ancient and modern literature on all phases of onions and 

 onion culture, but it contains no mention of smut or any trouble which might be 

 interpreted as smut previous to the middle of the 19th century, when it was first 

 found in New England. If smut is of Old World origin, this omission is certainly 

 nothing short of remarkable. Is it not more probable that it occurred in an incon- 

 spicuous way on some other closely related American plant and thence passed over 

 to the onion which it found to be a more suitable host? To be sure, we have no 

 published record of its occurrence on any othet American plant (except for one 

 record of a wild onion, Allium Ncvidense, in the Far West) ; but when one recalls 

 that new diseases and new hosts of disease organisms are being discovered every day, 

 and that it may occur on its wild host plant only as an inconspicuous seedling dis- 

 ease, this does not seem to be a serious objection. The fact that the disease has 

 been found on twenty-six other species of plants of the same genus not previously 

 reported as affected by smut (p. 8) indicates that all of the host plants of the onion 

 smut have not yet been found. 



The first published record of the existence of onion smut which the wiiters have 

 seen is in the Proceedings of the Essex Institute for 1857 (31: 207, 211-214)*. 



Since this interesting article seems to have escaped the notice of other students 

 of the diseaset and is in a rather inaccessible publication we quote it in full. At a 

 field meeting of the society at Beverly, Mass., on June 24, 1857, a letter was read by 

 the secretary from Mr. J. W. Proctor,! a Danvers farmer. This letter according to 

 the report of the secretary, Mr. Wheatland, 



"treated of the smut of the onion and of a maggot, which attacks that vegetable, 

 threatening serious injury to the onion crops. He considered that at least half the 

 estimated crop of the present season would be lost. This letter was referred to a 

 committee consisting of Messrs. S. P. Fowler, George D. Phippin, and Henry F. 

 King, in order that it might make the necessary investigation, and report on the 

 subject at some subsequent meeting of the Society." 



At the next meeting, which was held at Wenham on July 10, 1857, Mr. Geo. D. 

 Phippin of Salem, made the following report on onion smut: 



"As to the second agency found so destructive in the cultivation of the onion 

 your committee report that the smut found growing in the leaves of the onion plant 

 has been examined under the microscope; but the specimens used were so imperfect 

 that no information of a decisive character has been obtained. It is evident that 

 the smut of the onion is a parasitical fungus which originates and develops itself 

 within the cellular tissues of the leaves looking in some stages of growth like the fila- 

 ments of a Botrytis. It makes its appearance on the first leaf and descends toward 

 the root destroying the texture and rendering the leaf spongy and streaked with a 

 black dust. Perhaps then it may originate from the use of too much putrescent 



♦Numbers in parenthesis refer to bibliography in the back of this bulletin. Numbers after the colon 

 give the page on which statements referred to may be found. 



fAll the writers on onion smut who have mentioned the matter at all (Farlow, Thaxter, Stone, Walker, 

 Cornu, et al.) quote as the first published record, the observation of Ware (51), 12 years later. Probably a 

 more thorough search through the agricultural literature of Essex County just previous to 1S57 would reveal 

 earlier allusions to smut. 



JTen years previous to this date Mr. Proctor, who appears to have been an onion grower of considerable 

 prominence, presented "An Essay on the Cultivation of the Onion" before the Essex Agricultural Society 

 (33) in which he gave considerable attention to the pests and enemies of the onion, but no mention is made 

 of smut. The fact that a practical, keen observer like Mr. Proctor had never seen smut leads us to believe 

 that it was not present at that early date in the Danvers section. 



