DISEASES OF THE PATE PALM. 125 



Prepare the mixture as follows : 



Powder the copper sulphate and then dissolve it in a little 

 hot water in an earthenware or a wooden vessel. When quite 

 cold add 28-36 gallons (7 to 9 kerosene tinfuls) of cold water to 

 the solution. 



Next slowly and thoroughly slake the quicklime in another 

 vessel by first adding to it about a pint of water and repeatedly 

 adding that amount of water as the previously applied liquid is 

 used up by the lime. Continue until about a kerosene tinful of 

 water has been added and the whole lime is dissolved into a 

 cream. The lime must be stirred well during this slaking process. 

 When quite cold stir the lime water again and filter it through a 

 coarse sacking into the vessel containing the copper sulphate, 

 stirring the copper sulphate all the time. Add water to the 

 mixture to make the whole lot up to about 50 gallons (12J 

 kerosene tinfuls) and apply within 6-8 hours after its preparation 

 as the ingredients are not easily kept in suspension in the liquid 

 longer than that, and the mixture is not so adherent to the plants. 



The above proportions of lime and copper sulphate must 

 be adhered to carefully as these proportions are required to 

 neutralise each other. The copper sulphate by itself is injurious 

 to plants therefore none of it should exist in the free state in the 

 prepared wash. This is sometimes the case when old or clayey 

 quicklime is used. 



To test whether the mixture is properly made, dip a clear 

 steel knife blade into the solution. If a brown deposit appears 

 on it, it indicates that free copper sulphate exists in the wash, 

 therefore a little more lime should be added to it. When a 

 great excess of lime is used the wash is almost useless. A wash 

 as near the neutral point as possible should be prepared. 



The exact amount of water mentioned above is not essential 

 but that is the amount found useful when the mixture is used 

 as a general fungicide in various parts of the world. 



The wash should be applied with a spraying machine in all 

 cases. 



