New York Agricultural Experiment Station. 189 



alsike clover seed will be impossible until the infested fields have 

 grown other crops which will tend to free the soil of the trefoil 

 seed. Farmers who meet with such an experience will undoubt- 

 edly see the wisdom of sowing pure seed. 



MISCELLANEOUS WEEDS AND SEEDS. 



RUSSIAN THISTLE. 



{8alsola kali var. tenuifolia) 



This seed continues to occur in many alfalfa seed samples and 

 the plant has been sent in to us for identification from several 

 sources, but it always appears during the first year after seeding 

 and no trouble from it in alfalfa fields after the first season has 

 been called to our attention. "We do not, therefore, consider it 

 a bad weed. 



ROQUETTE. 



{Eruca sativa) 



Roquette, like Russian thistle, has been found in alfalfa sam- 

 ples and has caused much anxiety to alfalfa growers because of 

 its rank growth in newly seeded fields. In all cases so far re- 

 ported to us nothing is seen of this plant after the first year and 

 it is evidently not to be feared in alfalfa fields of this State. 



JOHNSON GRASS. 



(Sorghum halapense) 



The seeds of this grass have been found in a number of alfalfa 

 samples this year. Though this plant has not been established in 

 New York State, it is such a troublesome weed in the 'South that 

 attention is called to it at this time. Any infonnation on the be- 

 havior of Johnson grass in New York State will be appreciated by 

 this Station. Johnson grass frequently occurs in alfalfa as a 

 naked kernel or caryopsis; the outer seed coverings or glumes 

 being removed by the cleaning processes. The viability of some 

 seeds would be destroyed by this treatment but our tests show that 



