Rural School Leaflet. 



991 



applied near trees or other useful plants. Both these substances are 

 very poisonous and care should be exercised in handling them. 



Wild mustard is a very troublesome weed in many sections. After 

 numerous trials, it has been fully demonstrated that mustard can be des- 

 troyed by the use of either copper sulphate or iron sulphate. If copper 

 sulphate is used, ten to twelve pounds are used in 50 gallons of water. 

 One hundred pounds of iron sulphate are used in 50 gallons of water. 

 Fifty gallons is enough for one acre. 



When spraying for mustard, better results are secured if the crop is 

 sprayed when the weed is young. Spraying should be done when the 



Fig. 68. — Mustard — sprayed and unsprayed 



mustard has six or eight leaves, and is from two to three inches 

 in height (See Fig. 67). 



Another effectual method of destroying weeds is by use of the short 

 summer fallow. Fallows have been practiced for centuries in Europe. 

 It is simply the practice of tilling the land so that no crop or weeds 

 can grow for a season. This is done in order that a profitable crop may 

 be secured the following year. The land will be free from weeds, but the 

 crop for one year will be lost. In the short summer fallow an early 

 crop is taken from the field and the land immediately plowed. The soil 



