470 THE SMALL GRAINS 



weeds are not effectively controlled by chemical sprays as 

 now used : hare's ear mustard, French weed, pink cockle, 

 perennial sow thistle, lamb's quarters, pigeon grass, wild 

 oats, chess, quack-grass, sweet-grass, and wild barley. 



Fifty-two gallons of solution to an acre were employed. 

 In the 52-gallon solution, 75 to 100 pounds of iron sulfate 

 were used, or 12 to 15 pounds of copper sulfate, or J of a 

 barrel of salt, or 1J pounds of sodium arsenite. 



515. Results of other trials. At the Rhode Island 

 Experiment Station it was found that wild mustard may 

 be controlled by spraying with iron sulfate, but wild rad- 

 ish could not be so controlled, as the method is practiced 

 at present. The most satisfactory results were secured 

 with a 20 per cent solution, applying the iron sulfate at 

 the rate of 100 to 150 pounds an acre. 



It is concluded from results at the Wisconsin Experi- 

 ment Station that the eradication of Canada thistle and 

 sow thistle by spraying is not practicable for the average 

 farmer. A 20 per cent solution of iron sulfate was very 

 effective, however, on wild mustard. Cockle bur, rag- 

 weed, dandelions, daisies, and wild lettuce were also par- 

 tially eradicated at the same time that tests were made 

 upon wild mustard. 



Buckwheat is usually very free of weeds, and is one 

 of the very best crops for cleaning the land of seedy an- 

 nuals. It is planted late, allowing much early cultivation 

 for germinating and then destroying weed seedlings. It 

 grows rapidly, and soon forms a dense shade ; the weeds, 

 therefore, though having a good chance to start, are pre- 

 vented growing later. 



