ON THE SUSCEPTIBILITY OF CLOVKi; AM) SOMK 



OTHER LEGl'MES TO STEAJ- DISEASE CAUSEJ) BY 



THE EELWORM, TYLENCHUS DIPSACI, 8YN. 



DE VA ST A TRIX, K t^H N. 



By T. COODEV, D.Sc. 



DepartmenI of Helmintholof/y, London School of Tropical Medicine, 



hite of I he Rothmnsted Experimental Station. 



(With P1m(.' 1, and Tables I and II in Text.) 



i.XTHoDrc'i'rox. 



Tt has l)een known for a number of years that red clover and rertain 

 other cultivated leuuniinous plants, besides many other non-le<iuminous 

 ones, are subject to attack from the eelworin, Ti/Ienchiis dipKocl. 



KUhn (1881) jjave an account of the disease produced in clover and 

 lucerne. Later on Ritzema-Bos (1892) showed that the worm attacking 

 clover was morpholooically indistinoui.shable from that attacking rye. 

 oats, hyacinth, carnation and several other cultivated |)Uints and certain 

 weeds. In England Miss Ormerod (1880-1 900) dealt with the subject in 

 many of her annual reports and gave a good account of the symptoms 

 })roduced by Tylenrhiis dipsaci. ])oiutiug out in 1899 the difFerences 

 between these symptoms and tliose prodiK I'd hv tlie fungus Sclfirotinin 

 trifolionim. 



More recently Amos (1919) has published a paper dealing witli i.lie 

 difficulties of growing clover, in which lie states in general terms the 

 comparative susceptibilitv of a number of different kinds of clover and 

 other leguminous plants. Also Byars (1920) and Smith (1919) liave ipiite 



