164 MASSACHUSETTS AGRICULTURE. 



MASSACHUSETTS. 



THE ONION-SMUT.* 



By W. G. Farlow, 



Assistant Professor of Botany in Harvard University. 



Not quite two years ago, our attention was called by Pro- 

 fessor W. H. Brewer of New Haven, to a disease of onions, 

 popularly known as the smut, which was causing great injury 

 in some parts of Connecticut, particularly near Wethersfield, 

 where, as is well known, the onion forms the most important 

 crop. We were not successful in obtaining any specimens 

 of the disease until the spring of 1876, when we received some 

 young onions affected with the smut, from Mr. S. B. Sherwood 

 of Green's Farms, .Conn., and Mr. S. M. Wells of Wethersfield. 

 From the letters of Professor Brewer, and the statements of 

 Mr. Sherwood and Mr. Wells, it seems that the smut makes 

 its appearance in May, sometimes when the plants are only 

 an inch high, but often not until they have reached a larger 

 size. In some cases the bulbs do not grow at all, in others 

 they grow to be as large as one's fist, but are "diseased between 

 the layers." The injury to the onion crop is estimated by 

 the gentlemen just mentioned at several thousand dollars a 

 year in the region of Southport and Wethersfield, Conn., and 

 they agree in stating that no application of sulphate of copper 

 or similar substance to the seed has proved of any use where 

 the disease has once got into the soil. 



More recently, we have had some conversation with Mr. 

 Benjamin P. Ware of Marblehead, Mass., who is an extensive 

 cultivator of onions, and has suffered at times severe pecuniary 

 loss in consequence of the injury to the crop caused by the 

 smut. Mr. Ware makes the statement that his onions are 

 attacked by two distinct diseases, one of which is found on 

 the plants which are going to seed, the other on the young 

 seedlings. The former appears like a white flocculent mould, 



* See Plate, frontispiece. 



