FUNGOUS DISEASES. 1 1 9 



Variety tests show that round turnips growing 

 well out of the soil are much less susceptible to the 

 disease than those varieties which run deeply and 

 are much branched. 



Irrigation favors the development of the club 

 root. Buckwheat seems to have a wholesome effect 

 upon land infested with the club root germs, but 

 further tests are needed to warrant conclusions. 



Shading has very little effect upon the activity 

 of the Plasmodiophora. 



Many kinds of plants may be infested with the 

 disease, but none outside of the mustard family were 

 found susceptible. 



The club root germs will remain alive for a 

 long time in the soil. 



Soil may be inoculated by using infested cab- 

 bage or turnips, either applied directly to the soil or 

 by using the manure from animals to which the club 

 root cabbages or turnips have been fed. 



Winter ridging of the infested land decreases 

 the disease in the following crop, but only to a 

 limited extent. 



BLACK ROT.* 



A great many parasitic diseases of plants have 

 been known for many years, but now and then an 

 apparently new malady makes its appearance, sweep- 

 ing through sections of country, leaving devastated 

 fields in its wake. Such is the case with the cabbage 

 rot, a disease whose nature has not hitherto been 

 thoroughly recognized, but one which has made 



*Condensed from Bulletin No. 66 of the Vermont Experiment Station, 

 by Professor L. R. Jones ; and from Bulletin No. 65 of the Wisconsin Experi- 

 ment Station, by Professor H. L. Russell, from which the illustrations 

 used were reproduced 



