76 Weeds. 



be followed with all the crops grown for 

 seed, especially grasses and clovers. It 

 has already been mentioned that weed seeds 

 frequently come to us in the seed grains 

 brought to our farms for the purpose of 

 effecting a change of seed. The danger 

 here, though not easily altogether averted, 

 may yet be lessened. If the seed of all 

 cereal grains were carefully prepared by 

 such a process of screening as would sift 

 out all the smaller seeds from it, deteriora- 

 tion in the seed of this class of crops would 

 be very much less rapid than it now is, and 

 a change of seed would much seldomer be 

 required. The farmer who is so careless 

 as to sow unclean seed of his own raising, 

 or so foolish as to purchase unclean seed 

 from the seedsman because it can be bought 

 cheaply is, however, not likely to be greatly 

 concerned as to whether his farm is clean 

 or is not clean. 



5. Thoroughly clean the thrashing 

 machine before using it. Thrashing 

 machines, especially if they come from a 

 farm with a reputation for uncleanness, 

 should be carefully swept before being set 

 to work. If, in addition, they are made 

 at the first to run empty for a short time. 



