New York Agricultural Experiment Station. 107 



CONCERNING THE PREVENTION OF BLACK ROT. 



No practical treatment for black rot has yet been discovered. 

 It has been shown that the leaf-pulling- treatment instead of being 

 beneficial is positively harmful. Rotation of crops affords little 

 if any protection against the disease. Placing the seed bed on 

 soil which has never grown cabbage or related plants is a good 

 practice, but it remains yet to be proven that it is of any real value 

 as a preventive of black rot. Spraying with resin-bordeaux mix- 

 ture is, perhaps, worthy of trial, but can not be relied upon to 

 control the disease. 



The virulence of the disease depends largely upon weather con- 

 ditions, and it is unfortunate that the conditions most favorable 

 to the growth of cabbage are also the most favorable to the dis- 

 ease. Rapidly growing plants are especially liable to be attacked. 



It appears to the writers that before much progress can be made 

 toward the control of the disease it will be necessary to deter- 

 mine more definitely how the germs spread from plant to plant 

 and field to field; also, to what extent they live over winter in 

 the soil, to what extent root infection occurs and whether the 

 disease is transmitted through the seed. 



