226 DRY FARMING 



be lessened but not entirely controlled. By using the 

 duck-foot cultivator small weeds of all types can be 

 killed. By harrowing, young weeds can often be les- 

 sened at a very low cost whether they appear in the 

 fallow or growing crop. 



Digging by hand is not a popular method of weed 

 control but when Canada or Sow Thistle are first ob- 

 served in small patches they should be "eradicated" by 

 hand if the area is too small to cultivate satisfactorily 

 with machinery. 



Crop Rotations. — If we had good crop rotations we 

 could control our weeds at a small fraction of the present 

 cost. In considering this question four important facts 

 should be kept in mind: 



1. Perennial hay crops will control weeds having short- 

 lived seeds, such as Wild Oats, providing the in- 

 troduction of other Wild Oats seeds is prevented. 



2. An occasional fallow encourages germination of 

 weed seeds in the soil and permits killing the 

 young plants shortly after they begin to grow. 



3. Intertilled crops will lessen the necessity for fal- 

 lowing to kill weeds but may not prove profitable 

 on a large acreage under present economic condi- 

 tions, 



4. The use of early maturing crops that may be har- 

 vested before weeds ripen enables one to prevent 

 seed development. Among these early crops are 

 (1) grain crops to be cut for forage, (2) Winter 

 rye and, (3) early barley. 



Chemical Sprays. — A twenty per cent, solution of Iron 

 Sulphate (100 pounds to 50 gallons of water per acre), 

 applied on bright sunny days td mustard coming into 

 bloom, will prevent inuch of it developing. Another 



