VEGETABLE AND FIELD CROPS 253 



stiff black spines or hairs. Sometimes flattened black 

 sclerotia accompany these growths. 



While the disease is not conspicuous before harvest, it 

 is really present in incipient stage upon the bulbs in the 

 field and continues to develop rapidly under storage con- 

 ditions. Here it may pass to new bulbs by contact or by 

 air currents. These dangers are much augmented by a 

 moist atmosphere. While the growth is not retarded 

 appreciably by this disease, the value of the onion is often 

 much reduced by the disfiguring growth, and the loss from 

 rot induced by it is also considerable. 



Onions before they are placed in storage should be well 

 dried. Storage bins with good ventilation, so arranged 

 as to prevent all heating or sweating of the bulbs, should 

 be provided. No infected bulbs should be stored, since 

 they will carry infection to the sound bulbs. Bins that 

 are known to be infected, i.e., which held infected onions 

 in any preceding year, should be disinfected by a thorough 

 spraying with Bordeaux mixture or plain bluestone so- 

 lution. 



Soft rot {Bacillus^ sp.). — This soft rot appeared in New 

 York in 1898. In many cases one third to one half of the 

 crop was destroyed, and the sale of the balance injured 

 because the news of the presence of the rot had reached 

 the buyers. 



Where the rot starts at the tip of the bulb, the onion may 

 appear sound, but pressure at the top or sectioning with 

 a knife reveals the rot within. Frequently a single leaf 

 scale is rotten entirely around the onion, which is other- 



1 Stewart, F. C, N.Y. (Geneva) Agr. Exp. Sta. Bui. 164, December 



