168 BOARD OF AGRICULTURE. [Jan., 



the early stages of the smut, shows that the fungus consists of a 

 multitude of small filaments, or threads, collected in knots and 

 stringy masses within the substance of the onion leaves and bulbs. 

 At a later period a vast multitude of dark particles are found; 

 these are so fine that they can only be seen in a mass as a black, 

 dusty powder. At this time the skin of the leaves becomes broken, 

 usually in long, narrow lines, and this dust, which is really the 

 spores of the fungus, is set free. Unlike the rusts, the smut fun- 

 gus is not believed to pass in its development through distinct 

 states or forms, upon widely separated plants, and, therefore, for 

 its prevention we do not have to look outside of onion plants. 

 It is generally supposed that it has come from the wild onion, or 

 garlic, and, therefore, in the extermination of all such wild plants 

 in the region a remedy may be found. When the smut has been 

 allowed to perfect itself, the soil is more or less filled with the 

 spores, and gives truth to the expression among afflicted onion 

 growers, that " the disease is in the ground." The question of 

 ridding the soil of the onion smut resolves itself into simply this : 

 "How kill the spores therein ?" Manuring the land, and giving 

 it the highest culture, and continuing the growing of onions, will 

 not do it. It may be that by so domg the smut will not be very 

 ti'oublesome, simply because strong, healthy plants are better able 

 to withstand its attacks. This is a law which holds good with 

 diseases in general ; the better the health — the more vigorous the 

 subject, the greater the vitality; the less, disposed is the subject to 

 disorders. 



But this is not the best way to treat the onion fields that have been 

 smutted, because they are usually already under good culture. 

 There seems to be but one way — cease growing onions on the land for 

 a term of years sufficient to exhaust the vitality of the dormant 

 smut spores in the soil. Grow other crops, and in the course of 

 four or five years the smut spores will have died. At present, the 

 trouble is not wide spread, and knowing the fatal nature of the pest, 

 every precaution should be taken that its limits be not extended. 

 Those buying and selling seed should bear this in mind, for a little 

 care in not taking seed from a smutty locality may make thou- 

 sands, if not millions, of dollars difference in the great and grow- 

 ing onion interest of our country. 



