1?2 ELEMENTS OF FARM PRACTICE 



Perennial weeds grow year after year, or until something 

 unusual happens to kill them. In this class are found 

 the very worst weeds with which the farmer has to contend. 

 Some of the more common and more troublesome peren- 

 nial weeds are quack grass, Canada thistle, sow thistle, 

 morning-glory, and curled dock. These weeds not only 

 grow from seed, but persist in growing and spreading even 

 if prevented from seeding. They grow from underground 

 root stalks or stems. When the land is plowed or culti- 

 vated, instead of the roots' being killed they are broken into 

 pieces which start to grow and produce new plants. 



To eradicate perennial weeds is one of the most difficult 

 jobs a farmer has to do. Many farmers do get rid of them, 

 but some farmers just give up and say it cannot be done. 

 To kill them one must not only prevent the plants from 

 seeding, but must kill the roots as well. The roots can 

 be killed only by digging them out of the ground and re- 

 moving them from the field, or by starving them out. The 

 roots can be starved only by preventing them from forming 

 leaves. This can be done best by plowing the land very 

 thoroughly, and then by disking and harrowing very care- 

 fully and very often for about three months. This requires 

 lots of work, and is very expensive; but, if the work is care- 

 fully done, even quack grass can be eradicated. 



Spraying. — Certain weeds, such as mustard, ragweed, 

 and dandelions, may be killed by spraying with chemicals, 

 even when growing in a grain field without injuring the 

 grain. Either sulphate of iron or sulphate of copper may 

 be used, the former being the cheaper. The solution should 

 be sprayed on the weeds by means of a machine made for 

 this purpose. For mustard or dandelions mix 100 pounds 

 of iron sulphate in 50 gallons of water. Stir thoroughly and 

 spray on a bright day. About 50 gallons is required for an 

 acre. On the general diversified farm, however, where crops 

 are rotated, and hay and pasture crops and cultivated crops 

 are grown, the kinds of weeds that can be killed by spraying 

 are kept well in check by regular methods of cultivation. 



Bulletins. — For further information about weeds, how 

 to identify them and eradicate them, write to your State 

 Experiment Station and ask for bulletins on weeds. 



