ISTew York Agkicultukal Experiment Station. 173 



placed in a moist chamber and inoculated upon the cut surface 

 •with bits of rotten onion. At the end of a week there was only a 

 trace of rot at the points of inoculation. Similar inoculations 

 with pure cultures of the Fusarium likewise gave negative results. 

 Sound onions, in moist chamber, were bored to the center with an 

 awl and bits of rotten onion introduced into the wounds. At the 

 end of a week there were no signs of rot. This experiment was 

 repeated several times and always with the same result — the onions 

 refused to rot. During these experiments the temperature of the 

 room varied from 21° to 26° C. (70° to 79° Fahr.). 



Finally, sound onions inoculated externally with bits of rotten 

 tissue were immersed in sterilized water and placed in an incu- 

 bator kept at a temperature of 36° C. (97° Fahr.). Other sound 

 onions were treated in the same way, except that they were not 

 inoculated. Still others were inoculated by boring to the center 

 and introducing rotten tissue. These latter were then put into 

 the incubator with the others, but not immersed in water. At the 

 end of six days all of the onions immersed in water were rotten,, 

 including checks; while those which had been inoculated, but kept 

 dry, were still perfectly sound. 



These experiments indicate that one important point in the pre- 

 vention of this rot is to keep the onions dry. In practice this is 

 to be accomplished by protecting stored onions from rain and by 

 draining the fields so that water will not stand upon them for any 

 length of time.* 



4 Since the above was written, some observations have been made upon the- 

 crop of 1899. The season of 1899 was unusually dry in Orange county, and 

 yet there were a good many " slippery " onions in some fields. In looking- 

 over the onion fields, it was observed that some were almost entirely free from 

 weeds, while others were thickly overgrown with them. It was in the latter 

 kind of fields that the " slippery " onions occurred. The explanation of thia 

 appears to be that the weeds kept the onions wet by retaining the dew and 

 some light showers which fell just before harvest time, thereby furnishing 

 favorable conditions for the rot. Clean cultivation will hare a tendency to 

 reduce the amount of rot. 



