I04 Report of the Botanist of the 



The black rot germs are ividcly distributed. — As yet there is very 

 little exact knowledg-e concerning the mode of dissemination of 

 the black rot germs. Either the germs are now abundant in 

 nearly all soils in the cabbage-raising sections of the State, or 

 else they are disseminated with remarkable facility. Although 

 the virulence of the disease varies greatly in different fields it is 

 rare to find a field wholly exempt if the season is at all favorable 

 for the disease. It is very often destructive in fields which have 

 never before grown cabbage or other cultivated plants of the 

 cabbage family. 



Because of the wide distribution of the disease germs it is 

 apparently useless to attempt to prevent the spread of the disease 

 by the removal of diseased plants. At least, no success is to be 

 expected until it is definitely known how the germs are dissem- 

 inated. 



EXPERIMENTS ON CAULIFLOWER. 



During the past four seasons in which the cabbage experi- 

 ments have been in progress at Phelps similar experiments have 

 been carried on with cauliflower on Long Island; but these 

 experiments have been barren of results because of a lack of the 

 disease. During four consecutive seasons there was not enough 

 black rot in the experiment fields to give the leaf-pulling treat- 

 ment a fair trial. Nevertheless, it will be abandoned. Since it is 

 a pronounced failure with cabbage it is altogether likely that it 

 will not succeed with cauliflower for the same reasons. 



On cauliflower, spraying with resin-bordeaux mixture^^ has also 

 been tried during four seasons. Owing to a scarcity of the dis- 

 ease the results are inconclusive but sufficiently encouraging to 

 warrant the continuation of the experiments. 



i* For the preparation of resin-bordeaux mixture see Bulletin i88 of this Station, 

 page 247, footnote. 



