468 



Destruction of Charlock. 



To obtain the best results it is necessary to attend to the 

 following points : — 



1. The weed should not exceed three inches in height at 



the time of spraying, though fair success has some- 

 times attended treatment almost up to the time of 

 flowering. 



2. The solution must be made with clean, and, if pos- 



sible, soft water, and the vessels used in the process 

 should be of wood. 



3. The material, especially of copper sulphate, should 



be bought under a guarantee of purity of 98 per 

 cent. It should be obtained powdered, not in crystals. 

 This facilitates the solution. 



4. The solution must be applied by means of a machine 



that generates a fine spray under air pressure. A 

 hand machine of good construction will dress three 

 or four acres in a day, while a horse machine will 

 cover nearly ten times as much. The latter dis- 

 tributes the solution more perfectly and equally. 



5. Rain immediately after spraying will interfere with 



success, and the calmer the weather the more evenly 

 and effectively is the solution distributed. Moderate 

 dampness of the crop at the time of spraying is no 

 disadvantage, and better results will be got in dull 

 weather than in bright sun. 



